the shrinkage of a water surface : san francisco bay the shrinkage of a water surface : copyright © 2001 paul r. baumann san francisco bay, a water body of inspiring beauty and imposing magnitude, covers an area of over 450 square miles ( 1, 165. 5 square kilometers ) in size. outlined by softly shaped hills and low mountains it extends for approximately 50 miles ( 80 kilometers ) in its north - south length and from 12 miles ( 19 kilometers ) down to one ( 1. 6 kilometers ) mile in its east - west width. it opens to the pacific ocean through a spectacular gap called the golden gate. the bay provides a large and refreshing open space for the millions of people who live and work in the crowded urban and suburban landscapes ringing its shores. figure 1 provides an overview of the bay region. this landsat 7 enhanced thematic mapper plus ( etm + ) digital image was recorded during the late spring period of 1999. it is a true color composite generated by combining etm + spectral bands 3 ( visible - red ), 2 ( visible - green ), and 1 ( visible - blue ) as red, green, and blue, respectively. the image covers the san francisco bay and delta region. the cities of san francisco and oakland can be seen to the left of center. the bright white areas correspond to urban areas, which surround the bay. san pablo and suisun bays are to the northwest of center and the sacramento river is shown in the north / northeast portion of the image. the combination of the three visible bands makes it possible to detect the flow of water and build - up of sedimentation within the bay. the large green areas in the northeast section of the image are agricultural fields in the delta region of the central valley of california. the bright green colored features at the south end of the bay are diked salt ponds. this biologically rich and psychologically serene environment is quietly and steadily being modified by the encroachment of various human activities. the bay is shrinking in size through different sedimentation processes. the goal of this instructional module is to develop a methodology using satellite imagery to identify those water areas within the bay facing the immediate danger of disappearing and determine the amount of area in immediate danger. this methodology employs a landsat 7 etm + data set ( taken july 7, 1999 ), which covers a study area of 1501 rows by 1501 elements in size. this data set not only includes san francisco bay but also the urban development around it. the problem : the shrinkage of the


set ( taken july 7, 1999 ), which covers a study area of 1501 rows by 1501 elements in size. this data set not only includes san francisco bay but also the urban development around it. the problem : the shrinkage of the bay san francisco bay is facing some major environmental problems, foremost among these is the sedimentation, and thereby, the shrinkage of the bay. in 1850, san francisco bay along with san pablo and suisun bays covered around 680 square miles ( 1761 square kilometers ). by 1970, 250 square miles ( 647 square kilometers ) of water surface, mainly around the shores, had disappeared. see figure 2. this rapid reduction in the size of the bay corresponds to the growth and spread of human activities around the bay ' s shoreline, initially as agricultural development and salt pond construction followed by industrialization and urbanization. diking and filling in with trash and dry fill to create land for port facilities, airports, roads, industrial - commercial developments, and housing areas has been the main justification for reducing the bay ' s overall size. diking has also been done to make salt ponds. figure 3, produced under project gigalopolis at the university of california at santa barbara, shows the development and spread ( in red ) of the urban landscape within the bay area from 1800 to 2100. the years from 1800 to 1990 are based on actual census counts and the years after 1990 relate to population projections. in 1990, the san francisco - oakland metropolitan area had a population of over six million people, making it the fourth largest urban concentration in the united states. in displaying the future population growth around the bay, figure 3 is also illustrating the magnitude of the problem of keeping the bay from shrinking. of the nearly 430 square miles ( 1114 square kilometers ) left, little over half is less than 12 feet ( 3. 66 meters ) deep and can be easily and quickly filled. if filled, the bay would shrink to 187 square miles ( 484 square kilometers ) and sections would be basically converted into rivers. unlike the chesapeake, delaware, and other bays located along the atlantic coastline, san francisco bay rests completely within the political domain of one state. however, its shores fall within nine counties and thirty - two cities with various vested interests. to complicate further the jurisdiction and control issue, about twenty - two percent of the bay ' s bottomland is in private ownership with another twenty - three percent owned by cities and other local governments. most of this bottomland is situated around the bay ' s present shoreline


the jurisdiction and control issue, about twenty - two percent of the bay ' s bottomland is in private ownership with another twenty - three percent owned by cities and other local governments. most of this bottomland is situated around the bay ' s present shoreline where most future development is likely to occur. california controls about fifty percent of the bay ' s bottom and the federal government only has about five percent. fortunately, the u. s. corps of engineers now has jurisdiction over all tidelands below mean high tide within the bay. because of this jurisdiction permits are now required for any diking or filling in, and to obtain a permit public notification and an environmental impact study are required. in addition, the san francisco bay conservation and development commission ( bcdc ) was established to bring together the various interest groups concerned about the use and development of the bay and to prepare a plan. the bcdc points out that as the result of its efforts the filling process has dropped from 2300 acres ( 931 ha ) per year before 1965 to now 15 acres ( 6 ha ) per year. also, the san francisco bay national wildlife refuge was created in the southern part of the bay and most of the salt ponds reside within the refuge. pond diking can significantly modify tidal zone habitats where salt water and fresh water blend to form biologically rich environments. these various governmental attempts to protect the bay can have an impact on the large and more publicized endeavors to fill in sections of the bay. however, the harder issue relates to how to control the acceleration of sedimentation due mainly to the increased paving of urban and suburban land surfaces which creates more and faster runoff of storm water. due to growing environmental concerns about storm water runoff, the national pollutant discharge elimination system ( npdes ) act was passed. the goal of npdes is the reduction and elimination of pollutants in storm water discharge from large and medium size municipal storm sewer systems. large sewer systems serve populations greater than 250, 000 and medium size systems deal with populations between 100, 000 and 250, 000. in the implementation of this act, the united states environmental protection agency published a series of regulations in november 1990 requiring municipalities and industries to obtain npdes storm water permits. since no federal funds were made available to achieve this mandated program, each local government has been faced with finding funds within its own budget, which generally means an increase in local property taxes. the physical environment the climate of the bay area can be described best as having warm, dry summers and mild, wet winters. under the koeppen


been faced with finding funds within its own budget, which generally means an increase in local property taxes. the physical environment the climate of the bay area can be described best as having warm, dry summers and mild, wet winters. under the koeppen climatic classification system the area is defined as a coastal mediterranean climate ( csb ). september is the warmest month with daily temperatures generally in the 70 ' s. january is the coolest month but winter temperatures rarely reach the freezing level. it is slightly warmer on the east shore of the bay than the west shore. total rainfall is about 20 inches during the year, coming predominately in the winter. figure 4 is a climatic data chart showing the monthly average temperatures and precipitation levels at the oakland airport. it illustrates the mild temperatures throughout the year and the summer dry condition. fog, generally associated with san francisco, occurs mainly on the pacific side of the city. the coastal mountains and hills keep most of the daytime fog from reaching within the bay area. during the summer the climate is associated with stable air coming from a subtropical high - pressure cell located over the pacific ocean, near the california coast. being so close to the land, due to the california cold ocean current, the air from the cell has little opportunity to collect any moisture from water surfaces to provide rainfall. precipitation amounts, during this period of the year, correspond to semiarid and arid conditions. during the winter when the entire global circulation system migrates southward, the subtropical high - pressure cell situated off of the california coast shifts south. this movement allows the westerlies from the cell to travel over more water before reaching the bay area, and thereby, bringing in more precipitation. this rain comes mainly in the form of cyclonic precipitation but the hills throughout the bay area do produce some orographic rainfall. in some years the subtropical high - pressure cell does not shift away from its summer position resulting in a dry winter. after the normal dry summer, a dry winter followed by a second dry summer results in a drought situation. with respect to storm water runoff and sedimentation the winter is a much more active period especially at the beginning of the winter rainy season when impervious urban surfaces are covered with tremendous amounts of grit and hillsides are bare of vegetation from a long, dry summer. due to the excellent climate in the bay area few homes need air conditioning. however, the filling of the bay can significantly change this situation. the daily tidal flow within the bay serves as a natural air conditioning system. decreasing the volume and


dry summer. due to the excellent climate in the bay area few homes need air conditioning. however, the filling of the bay can significantly change this situation. the daily tidal flow within the bay serves as a natural air conditioning system. decreasing the volume and surface area of water adversely impacts this system. it also increases the probability of more temperature inversions, the prime condition for air pollution and smog. in addition to the tidal flow, the salt ponds maintain the water level, and thereby, the natural air conditioning. the elimination of the ponds to protect wildlife habitats and reduce the filling process will change this situation. this situation might occur anyway due to the economics involved in salt production. ironically, the excellent climate, one of the principal reasons why so many people have elected to live in the bay area, might be changed by too many people living there. in 1830, french scientist gustave gaspard de coriolis identified what is now called the coriolis force. the coriolis force deals with the movement of fluids such as water and air on the face of the earth and how they are deflected away from their original direction of movement due to the earth ' s rotation. in the northern hemisphere, fluids are deflected to the right from their point of origin and in the southern hemisphere they are deflected to the left. most often the coriolis force is discussed in respect to the flow of air but it also affects the flow of water. the greeks understood this situation when they built the city of alexandria in egypt. they placed the city to the left or on the west side of the nile so that sediment carried by the nile into the mediterranean sea would not clog the city ' s port. on leaving the nile, point of origin, sediment is deflected to the right or to the east of the river. today, this situation creates problems for the city of port said, which is at the mediterranean entrance to the suez canal. the city regularly has to dredge its port of sediment. at the south end of san francisco bay, the coyote river carries sediment into the bay in the same manner as the nile brings sediment into the mediterranean sea. over geological time the east side of the bay has filled in more than the west side so that today the east side has a large alluvial plain. other physical processes have also been involved in the creation of this plain. the urbanization and industrialization processes in recent decades have promoted horizontal growth versus vertical growth. for example, commercial activities and industries prefer to have single


a large alluvial plain. other physical processes have also been involved in the creation of this plain. the urbanization and industrialization processes in recent decades have promoted horizontal growth versus vertical growth. for example, commercial activities and industries prefer to have single story buildings, which spread out horizontally over the land rather than having vertical structures several stories tall. these processes generate the need for large areas of flat land. the alluvial plain on the east side of the bay meets this need. thus, the industrial center of the bay is oakland, not san francisco. san francisco and the other cities on the west side of the bay lack flat land for development. the horizontal expansion of urbanization has resulted in more land being changed into impervious surfaces. on april 15, 1999, landsat 7 was successfully placed into orbit and its enhanced thematic mapper plus ( etm + ) started recording images. the data set used in this module comes from an etm + image recorded on july 7, 1999. it covers san francisco bay but not san pablo and suisun bays. it is 1501 lines by 1501 elements in size. the software package earthscenes is used throughout this module and all the functions required to complete tasks associated with this lesson are available in this package. an etm + data set has eight bands. six of the bands are identical to the landsat 4 and 5 thematic mapper bands. they cover the same spectral range and have the same spatial resolution of 30m by 30m. these spectral bands are 1 - 5 and 7. the thermal infrared band, band 6, found on the etm + scanner is also available but its spatial resolution has increased from 120m by 120m to 60m by 60m. it covers the same spectral ranges ; however, the data have been provided in low and high gain, making for two bands, band 6l and band 6h. finally, there is a panchromatic band, which has a wide spectral range extending from the green visible through the near infrared portion of the spectrum. this band has a spatial resolution of 15m by 15m. the spatial resolution of the panchromatic band provided with this module has been modified in order to relate to the size of the bands, which is 30m by 30m. to convert all the bands to correspond to the panchromatic band size of 15m x 15m would result in some of the images appearing fuzzy. also, to cover the geographic area being studied a data set with a 15m by 15m resolution would


convert all the bands to correspond to the panchromatic band size of 15m x 15m would result in some of the images appearing fuzzy. also, to cover the geographic area being studied a data set with a 15m by 15m resolution would be four times the size of the present data set and would introduce some problems of displaying reasonable size areas for the lesson. the panchromatic band was reduced down in size by dropping out every other element and every other line. the panchromatic will not be needed for this particular module. band 6l and band 6h are not included with the data set provided for this module. they introduced certain technical issues when trying to convert them to the same resolution as the other bands. before attempting to measure the amount of water area that is in danger of being lost, some observations might help in demonstrating how serious the situation is. the visible bands are better for detecting differences within a water body than the near and middle infrared bands, which are good for separating water surfaces from land conditions. figure 5, a true color composite of bands 1, 2, and 3, shows that urbanization of the east side of the bay around oakland and san leandro extends down to the water ' s edge. however, in moving southward on this side of the bay, urbanization appears to have shifted away from the water ' s edge, and large wetlands and salt ponds exist between the bay and the urban development. most of this area is under pressure to be developed because of the need for flat land and economic development. figure 6 is a false color composite ( bands 4, 3 and 2 ), which shows the west side of the bay directly across from the wetlands and salt ponds on the east side of the bay. the west side of the bay faces even greater pressure for flat land because so little of such land exists initially. an examination of figure 6 shows how urbanization is moving southward taking over the wetlands and salt ponds. thus, a true concern exists for the potential shrinkage of the bay. once the wetlands and salt ponds are developed, the next step is to extend further out into the bay. by the removal of the wetlands and the straightening out of streams, sediment from the surrounding hills and grit from impervious urban surfaces wash into the bay. figure 7 is a false color composite ( bands 4, 3 and 2 ) superimposed on a navigational chart of the area around the city of san lorenzo. note on the color composite that a delta shaped area extends into the bay. this is deposition of sediment


a false color composite ( bands 4, 3 and 2 ) superimposed on a navigational chart of the area around the city of san lorenzo. note on the color composite that a delta shaped area extends into the bay. this is deposition of sediment and grit being carried by the san lorenzo creek into the bay. note on the chart that this deposition is described as being " foul. " there are two other items to be noted on the chart. the spatial pattern of the sediment and grit flowing into the bay does not correspond to the pattern appearing on the satellite image. the chart, like any map, is an attempt to generalize conditions based on limited information. the image most likely provides a more accurate picture. the second item is the numbers in the bay. these are depth figures given in feet. the bay is only 1 to 2 feet deep in this area. it would not take too much effort to fill in this area. figure 8 covers an area immediately north of the area shown in figure 7. a boat moving in a straight line from a marina can be observed in this composite. this boat and its wake cannot be detected in the regular images or other color composites. this color composite is the result of stretching the three visible bands twice. the navigational chart shows why this boat is moving along in a straight line. a path in the bay floor has been opened, which allows boats from the marina to reach deeper water. another reason why this path exists can be seen on the chart. it contains the sewer line for mulford gardens and san leandro. thus, people with yachts have to follow a sewer line to reach open water. note the area immediately east and southeast of the marina and compare it to the same area on the figure 7 color composite. the bright red areas on figure 7 form a golf course associated with the marina. it is hard to detect the golf course on the figure 8 color composite. the chart shows part of the golf course as being built on the " foul " area. this difference is due to the chart being produced in 1986 and the satellite image being taken in 1999. however, this difference also illustrates how quickly a " foul " land area was converted into a land use to fulfill certain human interests. the initial step in addressing the problem of identifying endangered areas within the bay is to select the best spectral band to use for the analysis. as indicated previously the three visible bands show variations within water, which make them the best candidates for the task. the near and middle infrared bands do not provide much differentiation within


within the bay is to select the best spectral band to use for the analysis. as indicated previously the three visible bands show variations within water, which make them the best candidates for the task. the near and middle infrared bands do not provide much differentiation within water but they do an excellent job of separating water from land. the thermal infrared bands do not have the spatial detail required. the panchromatic band is another possible candidate but its wide spectral range includes the near infrared portion of the spectrum, which makes it a weaker candidate. each of three visible bands displays spectral variations within the bay. since these bands are conveying reflective energy, it is important to determine if they are showing surface conditions on the water or water depth. the deeper the water, the harder it becomes to identify depth. a deep channel is maintained at the south end of the bay as indicated on the chart portion of figure 9. this channel is around 40 feet deep, which makes it difficult for the visible bands to identify it. however, the channel can be seen on all three bands, which have been superimposed on the chart in figure 9. this indicates that any one of the bands can be used to identify more shallow water areas. a closer examination of the three bands reveals another important item. the reflective nature of the salt ponds and wetlands in band 2 and band 3 is very similar to the reflective conditions within the bay, which might create problems separating these areas from water within the bay. band 1 has similar problems but not to the degree found in the other two bands. thus, band 1 will be used throughout the remainder of this lesson. band 1 was stretched between 63 and 190 to make better use of most of its data. see figure 10. its original dynamic range was 63 to 250 but only. 005 of its data values fell between 190 and 250. one of the difficulties in using band 1 or any of the visible bands is that many of the reflectance values associated with water surfaces are also found with land surfaces. it would be impossible to pick out the endangered water areas without also having a large amount of various land surfaces being selected. thus, it becomes necessary to negate or reduce land surface conditions. band 4 is the best spectral band to separate the land from the water. band 4 was first stretched between 14 and 197. next, the pixel read - out function was used to determine the water value range and the land value range, which were 1 - 52 and 53 - 250, respectively. using this information a density slice classification of band 4 was created with


and 197. next, the pixel read - out function was used to determine the water value range and the land value range, which were 1 - 52 and 53 - 250, respectively. using this information a density slice classification of band 4 was created with two classes, water and land. this classification was saved as a new layer in the earthscenes master image file. the data values in this layer were " 1s " and " 2s " for water and land. this layer was stretched and saved as a new layer. in the new layer all water surfaces had a value of 1 and all land surfaces a value of 250. this layer and the stretched band 1 layer were added to produce another layer. in adding the two layers together all values above 250 were designated to be truncated. since all the land values in the one layer were already 250, the addition of these values to the corresponding pixels in band 1 resulted in all the land pixels being above 250, and therefore, assigned the value of 250. in the case of the water pixels, only the value of 1 was being added to them and they would not exceed 250 and be truncated. figure 11 shows the new layer for band 1 with land surfaces appearing all in white and not conflicting with water, with respect to reflectance values. it might be desirable to create and view the histogram for this new layer. see figure 12. the water values barely appear on the histogram since all the land values have been assigned the value of 250 and that bar on the histogram dominates. a review of this histogram shows that the water values range between 11 and 102. with this information, the new layer was stretched to produce yet another layer. the values used in the stretching process were 1 and 105. since there were no water values above 102, placing the upper limit slightly above 102 kept the higher reflectance water pixels from merging with the land values. figure 13 shows the histogram for the new layer. the distribution across the histogram of the water pixel values is more spread out and easier to see in comparison to figure 12. figure 14 displays the new layer. this layer shows a much greater variation within the water surfaces but at the same time no variation in the land surfaces occurred. this is the layer from which the final classification and measurements will be obtained. the goal of the module is to identify the endangered areas within the bay and determine the amount of area in immediate danger of disappearing. those areas with one - half foot or less of water coverage should be viewed


the final classification and measurements will be obtained. the goal of the module is to identify the endangered areas within the bay and determine the amount of area in immediate danger of disappearing. those areas with one - half foot or less of water coverage should be viewed as areas that are already more land than water. these areas are basically those sections along the edge of the bay that have been designated as being " foul " or " muck " areas. as mentioned above, the navigational charts and the satellite image do not exactly agree on the coverage and location of these areas. the satellite image might be providing a more accurate presentation of these areas. for the purpose of this module, the areas between one - half to two feet of water coverage are the areas in immediate danger of disappearing and resulting in further shrinkage of the bay. the navigational charts are too large to present in a digital format for this lesson. thus, using key sections of the charts and the pixel read - out function, it was determined that the spectral values ranging between 186 and 249 corresponded reasonably close to the one - half to two foot water coverage area. when these values were compared to the histogram, figure 13, it was interesting to note the obvious break point in the histogram at 186. a density slice classification was done on the histogram producing three classes. see figure 15. the classes were : other water and wet surfaces ( 1 - 185 ), endangered water areas ( 186 - 249 ), and land surfaces ( 250 ). figure 16 is the three - class map created from this classification. the red colored areas are the endangered sections of the bay. they are mainly on the east side of the bay where sediment and grit from the hills and urban areas are dumped into the bay. winter rain, mainly in the form of cyclonic precipitation, comes across the bay moving eastward. the west side of the hills around the bay produce orographic rainfall ; whereas, the east side of the hills fall into rain shadow areas. the hills on the east side of the bay face westward and receive the rain, which in turn washes sediment and grit into the east side of the bay. the hills on the west side of the bay are in the rain shadow areas and do not receive as much rain resulting in less runoff. the rain around these hills occurs on the pacific ocean side and runoff flows more into the ocean. in addition, the impact of the coriolis force, which was previously discussed, must be considered. thus, it is not surprising to find the


. the rain around these hills occurs on the pacific ocean side and runoff flows more into the ocean. in addition, the impact of the coriolis force, which was previously discussed, must be considered. thus, it is not surprising to find the greatest concentration of the endangered areas on the east side of the bay. one pattern of interest is the red colored area farther out in the bay directly in line with san lorenzo creek and its " foul " delta. is sediment and grit from this stream flowing farther out into the bay? another pattern of interest is that the " foul " and " muck " areas were classified as water surfaces. in band 1, these areas have a low ( dark ) reflectance level similar to deep areas within the bay. in general, the classification produced very good results. some misclassifications occurred in the salt ponds and on the san mateo - hayward bridge crossing over the bay. these errors are minor and the classification is well within the 85 percent accuracy range accepted for land ( water ) cover maps. in addition to the map, pixel counts were provided for the three classes. these counts are provided in the below table. | other water and wet surfaces | | 621, 545 | | 138, 157. 6 | | 55, 912. 4 | | 215. 87 | | 559. 12 | | endangered water areas | | 71, 024 | | 15, 787. 3 | | 6, 389. 1 | | 24. 66 | | 63. 89 | with these figures and knowing that each pixel is 30m x 30m in area, various areal counts can be calculated. in other words, the endangered water areas within the bay cover 15, 787. 3 acres ( 6, 389. 1 ha ) or 24. 66 square miles ( 63. 89 square kilometers ). one must keep in mind that this instructional module only covers a portion of the entire bay region. it does take into account san pablo bay and suisun bay, which based on figure 1 appear to have a greater proportion of endangered water conditions than san francisco bay. below are the three key navigational charts used in this module. also, below are some web sites dealing with the topic of the bay and its endangered environment. access usgs - water flow, wetlands, water quality, hazards and more, from the us geological survey the bay institute of san francisco - dedicated to the protection and restoration of the ecosystems of san francisco bay, the sacramento - san joaquin delta, and the rivers


common lisp / advanced topics / numbers common lisp has much more support for performing number - crunching tasks than most programming languages. this is achieved by having support for large integers, rational numbers, and complex numbers, as well as many functions to work on them. types of numbers the hierarchy of the number type is as follows : fixnums and bignums fixnums are integers which are not too large and can be manipulated very efficiently. which numbers are considered fixnums is implementation - dependant, but all integers in [ - 215, 215 - 1 ] are guaranteed to be such. bignums are integers which are not fixnums. their size is limited by the amount of memory allocated for lisp, and as such they can be really large. operations on them are significantly slower than on fixnums. of course, that doesn ' t make them less useful. ratios represent the ratio of two integers. they have the form numerator / denominator. the function / which performs division always produces ratios when its arguments are integers or ratios. for example ( / 1 2 ) will result in 1 / 2, not 0. 5. other arithmetic operations also work fine with ratios. float is short for floating - point number, a datatype used to represent non - integer numbers in most programming languages. there are four kinds of floats in common lisp, which provide increasing precision ( implementation - dependent ). by default, implementations assume short floats, which have limited precision. to input a more precise float, other textual notations must be used, e. g., " 1. 0d0 " for a double - float. complex is a datatype for representing complex numbers. the notation for complexes is # c ( real imaginary ). real and imaginary parts are both either rational or floating - point. the operations that can be performed on complexes include all arithmetic operations and also many other functions which can be extended to complex numbers ( such as exponentiation and logarithm ). the following functions are defined for all kinds of numbers : - the arithmetical operations +, -, *, / are quite obvious ( note, though, that they can have more than two parameters ). - sin, cos, tan, acos, asin, atan provide trigonometric functions. - the same, with h at the end ( like asinh ) provide corresponding hyperbolic functions. - exp and expt perform exponentiation. exp accepts one parameter and calculates


as ratio with the largest absolute value that is less than absolute value of ratio, and round chooses an integer that is closest to ratio ( if there are two such numbers, an even integer is chosen ). note : these functions return two values ( see multiple values ). - ffloor, fceiling, ftruncate, fround are the same as above but the quotient is converted to the same float type as number. - ( mod a b ) returns the second value of ( floor a b ). - ( rem a b ) returns the second value of ( truncate a b ). - float converts its first argument ( a real ) to a float. it may be useful to avoid slow operations with rational numbers ( see example 1 ). the second optional argument may be supplied, which must be float - it will be used as a prototype. the result would be of the same floating - point type as a prototype. - rational and rationalize convert a real number to rational. when this number is a float rational returns a rational number that is mathematically equivalent to float. rationalize approximates the floating - point number. the former function usually produces ratios with a huge denominator so it ' s not as useful as you may think. - numerator and denominator return the corresponding parts of a rational number. - complex creates a complex number from its real part and imaginary part. functions realpart and imagpart return real and imaginary part of a number. predicate returns a non - nil result if it ' s true and nil if it is false. - zerop - the number is zero ( there may be several zeros in lisp - integer zero, real zero, complex zero, there may be negative zeros too ). - plusp, minusp - the real number is positive / negative. - evenp, oddp - the integer is odd / even. - integerp - the number is integer ( of the type integer - see type tree above ). - floatp - the number is float. - rationalp - the number is rational. - realp - the number is real. - complexp - the number is complex.


witness of his time “ goya is always a great artist and often a terrifying artist … adding to the spanish satirical spirit, fundamentally joyful and humorous, as it was in the time of cervantes, something much more modern, a quality that is highly appreciated in modern times, as is love for the indefinable, a terrifying sense of nature, of human features that have acquired animal characteristics … ” charles baudelaire, curiosites esthetiques ( 1868 ) the exhibition traces the artistic path of one of the greatest masters in art history. being the successor of the predominant art tradition of the times before him, goya is commemorated as the precursor of the modern narrative. bearing witness to a turbulent period in spain and europe, goya reflects the social circumstances of the era with a critical perspective. the exhibition unites his various oil paintings and engraving series and shed light on goya ’ s extraordinary imagination with his realistic and at times frigthening style that makes him one of the best narrators of darkness. francisco de goya was born on march 30th 1746 in zaragoza as the fourth child of a couple formed by the gilder jose goya and gracia lucientes. goya first began his schooling in the escuelas pias, where he coincided with his best friend martin zapater. after he attended to the school of the painter jose luzan where he learned the essence of aragonese painting. in 1775, goya moved to madrid, summoned by the court painter antonio rafael mengs, possibly at the request of his brother - in - law francisco bayeu, to work as painter of models in the royal tapestry factory of santa barbara. on 1786, he was appointed royal painter and after the crowning of charles iv on 1789, goya became court painter. in 1799, he appointed as the first court painter.


a birthstone is a gemstone, usually in the form of personal jewelry and most often in the form of a ring or pendant. each stone is traditionally associated with various qualities that symbolize the month of birth in the gregorian calendar. history of birthstones the first century jewish historian josephus proclaimed a connection between the twelve stones in aaron ' s breastplate, the twelve months of the year, and the twelve signs of the zodiac. translations and interpretations of the passage in exodus regarding the breastplate have varied widely, however, with josephus himself giving two different lists for the twelve stones ( kunz argues that josephus saw the breastplate of the second temple, not the one described in exodus ). st. jerome, referencing josephus, said the foundation stones of the new jerusalem ( revelation 21 : 19 – 20 ) would be appropriate for christians to use. in the eight and ninth century religious treaties were written associating a particular stone with an apostle, as revelation stated their name would be inscribed on the foundation stones, and his virtue. practice became to keep twelve stones and wear one a month. wearing a single birthstone is only a few centuries old, although modern authorities differ on dates : kunz places the custom in eighteenth century poland, while the gemological institute of america starts it in germany in the 1560s. modern lists of birthstones have little to do with either the breastplate or the foundation stones of christianity. tastes, customs and confusing translations have distanced them from their historical origins, with one author calling the 1912 kansas list " nothing but a piece of unfounded salesmanship. " ancient traditional birthstones are society - based birthstones. the table below contains many stones which are popular choices, often reflecting polish tradition. the gregorian calendar has poems matching each month with its birthstone. these are traditional stones of english - speaking societies. tiffany & co. published these poems " of unknown author " for the first time in a pamphlet in 1870. by her who in this month ( january ) is born no gem save garnets should be worn ; they will ensure her constancy, true friendship, and fidelity. the february - born shall find sincerity and peace of mind, freedom from passion and from care, if they an amethyst will wear. who in this world of ours their eyes in march first open shall be wise, in days of peril firm and brave, and wear a bloodstone to their grave. she who from april dates her years, diamonds shall wear, lest bitter tears for vain repentance


of ours their eyes in march first open shall be wise, in days of peril firm and brave, and wear a bloodstone to their grave. she who from april dates her years, diamonds shall wear, lest bitter tears for vain repentance flow ; this stone, emblem of innocence, is known. who first beholds the light of day in spring ' s sweet flowery month of may and wears an emerald all her life shall be a loved and happy wife. who comes with summer to this earth, and owes to june her hour of birth, with ring of agate on her hand can health, wealth, and long life command. the glowing ruby shall adorn, those who in july are born ; then they ' ll be exempt and free from love ' s doubts and anxiety. wear a sardonyx or for thee, no conjugal felicity ; the august - born without this stone, ` tis said, must live unloved and lone. a maiden born when september leaves are rustling in september ' s breeze, a sapphire on her brow should bind ` twill cure diseases of the mind. october ' s child is born for woe, and life ' s vicissitudes must know, but lay an opal on her breast, and hope will lull those woes to rest. who first comes to this world below with drear november ' s fog and snow, should prize the topaz ' s amber hue, emblem of friends and lovers true. if cold december gave you birth, the month of snow and ice and mirth, place on your hand a turquoise blue ; success will bless whate ' er you do. — gregorian birthstone poems in 1912, in an effort to standardize birthstones, the ( american ) national association of jewelers met in kansas and officially adopted a list. the jewelry industry council of america updated the list in 1952 by adding alexandrite to june and citrine to november ; specifying pink tourmaline for october ; replacing december ' s lapis with zircon ; and switching the primary / alternate gems in march. the most recent change occurred in october 2002, with the addition of tanzanite as a december birthstone. britain ' s national association of goldsmiths created their own standardized list of birthstones in 1937. | this section requires expansion. ( may 2012 ) | a hindu text from 1879, mani mala, lists gems for each month. birthstones by cultures early civilizations, such as those in india and babylon, have attributed gemstones


birthstones in 1937. | this section requires expansion. ( may 2012 ) | a hindu text from 1879, mani mala, lists gems for each month. birthstones by cultures early civilizations, such as those in india and babylon, have attributed gemstones with magical properties and especially to their relationship with the signs of the zodiac. over time, astrologers assigned gems of certain colors to the twelve signs of the zodiac to help people influence the planets in their favor. | aquarius | | 21 january – 21 february | | garnet | | pisces | | 22 february – 21 march | | amethyst | | aries | | 22 march – 20 april | | bloodstone | | taurus | | 21 april – 21 may | | sapphire | | gemini | | 22 may – 21 june | | agate | | cancer | | 21 june – 22 july | | emerald | | leo | | 23 july – 22 august | | onyx | | virgo | | 23 august – 22 september | | carnelian | | libra | | 23 september – 23 october | | chrysolite | | scorpio | | 24 october – 21 november | | beryl | | sagittarius | | 22 november – 21 december | | topaz | | capricorn | | 22 december – 21 january | | ruby | birthday ( day of the week ) stones while this word has also been used as synonym of birth stone ( see above ), there is a separate list of assignment according to the day of the week of the recipient ' s birth : - monday : pearl, crystal - tuesday : ruby, emerald - wednesday : amethyst, lodestone - thursday : sapphire, carnelian - friday : emerald, cat ' s eye - saturday : turquoise, diamond - sunday : topaz, diamond - kunz, george f ( 1913 ). the curious lore of precious stones. lippincott. pp. 275 – 306. - gleadow, rupert ( 2001 ). the origin of the zodiac. dover publications. pp. 130 – 131. - kunz ( 1913 ), p. 289 - knuth, bruce g. ( 2007 ). gems in myth, legend and lore ( revised edition ). parachute : jewelers press. p. 294. - knuth, p. 299 - knuth, p. 298 - knuth, p. 293 - knuth, p. 310 - gleadow, p. 132 - kunz ( 1913


jewelers press. p. 294. - knuth, p. 299 - knuth, p. 298 - knuth, p. 293 - knuth, p. 310 - gleadow, p. 132 - kunz ( 1913 ), p. 320 - farrington, oliver cummins ( 1903 ). gems and gem minerals. mumford. pp. 63 – 64. - kunz ( 1913 ), p. 317 - knuth, p. 311 - " tanzanite ". american gem trade association. retrieved 6 feb 2012. - " december birthstone : turquoise or tanzanite ". jewelry information center. retrieved 2011 dec 20. - " birthstones ". goldsmiths. retrieved 18 apr 2012. - knuth, p. 336 - kunz ( 1913 ), p. 315 - kunz ( 1913 ), p. 315 - " birthstones ". american gem trade association. retrieved 6 feb 2012. - " tips & tools : birthstones ". the national association of goldsmiths. retrieved april 18, 2012. - knuth, p. 336 - schwam, gena. " birthstones : myth and history : december - month of turquoise ". burke museum of natural history and culture. retrieved january 30, 2013. - " december birthstone ". international colored gemstone association. retrieved january 30, 2013. - knuth, p. 318 - kunz ( 1913 ), pp. 345 – 347 - kunz ( 1913 ), pp. 332 – 333


| | it has been suggested that hymns and hymn tunes be merged into this article. ( discuss ) proposed since may 2010. | a hymn tune is the melody of a musical composition to which a hymn text is sung. musically speaking, a hymn is generally understood to have four - part ( or more ) harmony, a fast harmonic rhythm ( chords change frequently ), and no refrain or chorus. from the late sixteenth century in england and scotland, when most people were not musically literate and learned melodies by rote, it was a common practice to sing a new text to a hymn tune the singers already knew which had a suitable meter and character. there are many hymn tunes which might fit a particular hymn : a hymn in long metre might be sung to any hymn tune in long metre, but the tunes might be as different as those tunes that have been used for centuries with hymns such as te lucis ante terminum, on one hand, and an arrangement of the calypso tune used with jamaica farewell, on the other. the practice of naming hymn tunes developed to help identify a particular tune. the name was chosen by the compiler of the tune book or hymnal or by the composer. the majority of names have a connection with the composer and many are place names. most hymnals provide a hymn tune index by name ( alphabetical ) and a hymn tune index by meter. in some instances a particular text and tune have an almost exclusive partnership with each other, such as reginald heber ' s text, " holy, holy, holy! " sung to john bacchus dykes ' s tune nicaea. in other instances a text may be used with a variety of tunes, such as " o for a thousand tongues to sing " sung to any of lyngham, oxford new, arden, lydia, richmond, azmon, or university. in yet other instances a tune may partner several texts, such as dix for " as with gladness, men of old ", " christ, whose glory fills the skies ", " god of mercy, god of grace ", " lord, to you immortal praise ", and " for the beauty of the earth ". by contrast, in germany and scandinavia, tune names were not typically used even when a hymn tune was used for more than one text. the custom in such cases was to use part of the first line of the first text with which the tune was associated as a name for the tune : for example lasst uns erfreuen ( all


was used for more than one text. the custom in such cases was to use part of the first line of the first text with which the tune was associated as a name for the tune : for example lasst uns erfreuen ( all creatures of our god and king ), gelobt sei gott ( good christian men ) and was lebet, was schwebet ( o worship the lord in the beauty of holiness ). renaming of tunes occurs from time to time, when a tune is chosen to be printed in a hymnal. when chorales were introduced in england during the eighteenth century, these tunes were sometimes given english - style tune names. the ravenscroft psalter of 1621 was the first english book which specified, by name, which tune should set each text. this followed the procedure used for the first time in the 1616 scottish psalter. in this early time of defining text / tune marriages, editors of different psalters were apt to use different names for the same tune. for example, the french tune, in the scottish psalter ( 1564 ), was the same tune as dundee in the ravenscroft psalter. common practice nowadays is for the composer of a tune to name it. typically, worship services in churches and synagogues include hymns which are sung by the congregation, accompanied by organ, or piano, and / or sometimes by guitars or other instruments. details of performance vary depending on the designated style of the service, or by the hymns themselves. some hymns specify unison singing, and other hymns are sung in parts ( usually soprano, alto, tenor, bass ). it is common practice for a congregation to sing all the hymns in unison, but in some traditions part singing is encouraged. sometimes, especially on longer texts, variety in the performance is introduced. varied performance practices may include : - varied harmonization for a stanza - descant added by sopranos, above the melody - " fauxbourdon " with the melody sung by tenors, and the harmonies sung by the other parts - a modulation ( usually for the last stanza ) into the next higher key other possibilities for varied performance can be invited through explanation either in the service bulletin or through verbal instruction by the pastor or the minister of music. combining some or all of these and can add interest to singing while enhancing the sense of the text. for example : - a stanza sung only by the choir - a stanza sung only by the congregation - a stanza sung only by men - a stanza sung only


some or all of these and can add interest to singing while enhancing the sense of the text. for example : - a stanza sung only by the choir - a stanza sung only by the congregation - a stanza sung only by men - a stanza sung only by women - a stanza sung only by the left half of the sanctuary - a stanza sung only by the right half of the sanctuary, etc. some hymn tunes lend themselves to being sung in canon. | | this section needs additional citations for verification. ( may 2008 ) | st. paul encourages christians to " let the word of christ dwell in you richly in all wisdom ; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the lord " ( col. 3 : 16 ), " [ s ] peaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the lord. " ( eph. 5 : 19 ). in 313 ad, the emperor constantine issued the edict of milan, which "... gave the christians the right to practice religion openly. " at that time the language of the people was latin. use of latin continued in the roman church long after it ceased to be the vernacular. by the early 16th century, the time of martin luther, the people had long since become only observers during the church services ; the singing was still in latin, and was done by choirs of priests and monks ( although the choirs sometimes included a few lay musicians as well ). as part of his efforts at reform, after martin luther prepared a version of the mass in latin, he prepared a version in german, adapting parts of the liturgical texts of the mass as chorales in the vernacular which could be sung and understood by the congregation. luther arranged the music for some of these by adapting the music of existing plainsong melodies ; he set other texts to newly composed tunes composed by others, or by himself. an example of the latter is the tune he composed for his german translation of psalm 46, ein feste burg. nicholas temperley wrote in the hymn tune index that luther " wished his congregations to take part in the singing, but in general they failed to do so " and " it was the calvinist, or ' reformed ', branches of protestantism that succeeded in establishing congregation hymn singing in worship. " luther ( 1483 – 1546 ) posted his theses against roman church practices, particularly " indulgences ", in 1517, which signalled the start of the reformation


protestantism that succeeded in establishing congregation hymn singing in worship. " luther ( 1483 – 1546 ) posted his theses against roman church practices, particularly " indulgences ", in 1517, which signalled the start of the reformation, "... but six or seven years passed after the inception of his reformation before he gave his thought to hymns.... luther wished to refine the worship of the church by excluding what he thought were needless complications while retaining, through the use of music, the essential spirit of christian devotion as enshrined in the church ' s tradition.... the year 1524 saw the first official luther hymnals. " luther wanted the congregation to participate in singing, with german texts sung to tunes straightforward enough for ordinary people to sing. " luther himself wrote many new religious texts to be used with well - known german folk songs. vom himmel hoch is one of these. " luther was a gifted and well - trained musician. he composed and found hymn tunes which were accessible for ordinary people to sing, and "... at the same time he encouraged church choirs to continue the tradition of polyphonic motets within the lutheran mass. he used various textures and styles of music in ways which were most appropriate and effective for each. " luther also adapted the music of existing plainsong melodies as hymn tunes. families enjoyed singing hymns in parts in their homes, for the family ' s enjoyment and edification, but unison singing was the custom in church. the reformed church and the ( french ) genevan psalter were the result of work by john calvin ( 1509 – 1564 ). his profound reverence for scripture "... caused him to insist that public praise in church should be confined to the language of the bible, adapted to the minimum extent required for congregational singing. he was "... the architect of the tradition of metrical psalmody. " calvin heard lutheran hymn singing while he served minister of the reformed church of strasbourg ( 1538 - 41 ). in fact, routley says, " [ m ] etrical psalmody was really born [ in strasbourg ] rather than in geneva. " clement marot ( c. 1497 - 1544 ) was a french court poet in strassbourg, who had begun setting psalms in metrical versions before calvin met him. although marot remained a catholic, calvin included marot ' s psalm versions in the psalter. the first geneva


was a french court poet in strassbourg, who had begun setting psalms in metrical versions before calvin met him. although marot remained a catholic, calvin included marot ' s psalm versions in the psalter. the first genevan psalter, 1542, contained 6 psalms by calvin and 30 by marot. the genevan psalter of 1562 contained all 150 psalms, and included the works of calvin ' s successor, theodore de beza ( 1509 – 1565 ). calvin did not approve of free religious texts ( hymns ) for use in church ; scripture was the only source of texts he approved. calvin endorsed only singing of metrical psalm texts, only in unison, only a cappella, with no harmonization and no accompanying instruments of any kind. tunes for the metrical psalm versions came from several men, including louis bourgeois ( c. 1501 - c. 1561 ), and claude goudemil ( c. 1525 - 1572 ). there were 110 different meters used for the texts in calvin ' s psalter, and 125 different tunes to set them. the music was very difficult ; the long tunes were hard for ordinary people to grasp. but later adaptations ( and simplifications ) of these tunes have added to current day hymn tunes repertoire. routley states that metrical psalmody was actually the first english protestant hymnody. england ' s reformation began when king henry viii separated the english church from the catholic church in rome in 1532. king henry ' s heir was king edward vi, who ascended to the throne in 1547. thomas sternhold ( d. 1549 ), groom of the royal wardrobe at the end of henry viii ' s reign and during edward vi ' s, "... began metricizing psalms for the edification of the young new king ( ten years old when he came to the throne in 1547 : sixteen when he died in 1553 ). " interestingly, sternhold ' s work paralleled marot ' s efforts in the french court ; sternhold ' s "... strong puritan strain moved him to replace with sacred songs the trivial secular music that was the court ' s normal entertainment ; this led him to versify certain psalms in the ballad metre that would enable them to be sung to tunes already known. " ( forest green, kingsfold, etc. ). the ballad meter, " which sternhold used very nearly without variation, " had 4 iambic lines


psalms in the ballad metre that would enable them to be sung to tunes already known. " ( forest green, kingsfold, etc. ). the ballad meter, " which sternhold used very nearly without variation, " had 4 iambic lines of 14 syllables, which breaks down to 8686 8686 ( our double common meter dcm or cmd ). also, a simpler " half length " tune evolved, now described as common meter ( cm = 8686 ). the english aimed at a psalter of all 150 psalms, virtually all in ballad meter. sternhold started the task, writing a total of 37 by the time he died, when john hopkins took over the work..... in the year of [ sternhold ' s ] death, a little book without music containing 44 psalms was published, of which 36 were by sternhold and eight by his collaborator john hopkins ( d. 1570 ). progress on the psalter was interrupted when king edward died in 1553, and his elder half sister mary ( " bloody mary " ) became queen. she tried to reinstate catholicism as the state religion. churchmen whose lives were threatened fled to the continent, some ending up in geneva, where they encountered the 1551 genevan psalter and the congregational singing which it supported. when elizabeth i ascended the throne after her sister ' s death in 1558, the exiled churchmen returned to england, bringing them an anglo - genevan psalter containing all the psalms plus a few tunes to set them, along with their desire to add congregational singing to church services. at that point work continued with the sternhold and hopkins psalter, adding psalms to it from the anglo - genevan psalter. the complete psalter was published in 1562 by john daye. " it is at this point important to remember that all these versions of the psalter, up to and including 1562, were published for private use. there was not, by 1562, strictly a ' church of england ' that could authorize the use of it in church. " the question of " authorization " of the sternhold and hopkins psalter for use in church services is discussed at length in john julian ' s dictionary of hymnology ; actually, the psalter was used in church whether it was ever officially authorized or not. " few books have had so long a career of influence. with the growing puritanism psalm - singing came to be esteemed the most divine part of god


, the psalter was used in church whether it was ever officially authorized or not. " few books have had so long a career of influence. with the growing puritanism psalm - singing came to be esteemed the most divine part of god ' s public service. " books did not print the music with hymns in hymnals, until the middle 19th century. tunes were printed separately in tune books. some of those printed in america in the 19th century ( for example, lowell mason ' s, or george root ' s ) use four staff systems. the tune name, but no composer credit, appears above each tune. the melody of the tune appears in the tenor ( fauxbourdon ), often with the first stanza words, printed above the tenor staff. during the decade 1791 - 1800, more than 8, 000 hymn tunes were printed in great britain and between 7, 000 and 8, 000 were printed in the united states ; during the decade 1801 - 1810, about 11, 000 hymn tunes were printed in great britain, while more than 15, 000 were printed in the united states. the total number of hymn tunes published with english - language texts in publications from 1535 up to and including 1820 is recorded as 159, 123. many early hymnals were published in editions which contained only texts. the early methodist movement provides an example. the co - founders, john wesley and his brother charles wesley, published several text - only collections, culminating in a collection of hymns, for the use of the people called methodists, in 1780. john wesley published tune books separately, culminating in sacred harmony, in 1780. in 1786, with the fifth edition of the text - only collection, wesley indicated at the head of each hymn the tune to which he intended it to be sung. among the tunes in sacred harmony that are still in use are derby, helmsley, and savannah. accompanists to hymn singing had a tune book, a volume which a collection of tunes, most without words, the exception being the occasional lyric when underlay of words to the music was ambiguous. an example of this was the bristol tune book. as more people became musically literate, it became more common to print the melody, or both melody and harmony in hymnals. contemporary practice in the u. s. and canada is to print hymn tunes so that lyrics underlay the music ; the more common practice in the uk is to print the hymn tunes on one page, and the hymn text either below, or on facing pages. among twentieth - century


s. and canada is to print hymn tunes so that lyrics underlay the music ; the more common practice in the uk is to print the hymn tunes on one page, and the hymn text either below, or on facing pages. among twentieth - century developments was the publishing of the english hymnal in 1906 under the music editorship of ralph vaughan williams. more recently, ethnic hymns and tunes have been included, descants have been added for some hymns, freer song - like styles have been accepted, and accompaniments by guitar and / or other instruments have been notated. - routley, erik ( 1980 ). christian hymns, an introduction to their story ( audio book ). princeton : prestige publications, inc. p. part 6, " the beginnings of english psalmody, 1549 – 1567 ". - compton ' s encyclopedia, vol. 5, 1968 edition. chicago : f. e. compton co. 1968. p. 548. - routley. christian hymns ( audio book ), op. cit. p. part 3, " reformation hymnody ". - temperley, nicholas ( 1998 ). the hymn tune index : a census of english - language hymn tunes in printed sources from 1535 to 1820. oxford university press. isbn 0 - 19 - 311150 - 0. - routley, erik ( 1981 ). the music of christian hymns. chicago : gia publications, inc. pp. 21 – 22. isbn 0 - 941050 - 00 - 9. - doran, carol ( 1990 ). " popular religious song ". in raymond f. glover. the hymnal 1982 companion. vol. 1. new york : the church hymnal corporation. p. 16. isbn 0 - 89869 - 143 - 5a. - doran. p. 21. unknown parameter | book = ignored ( help ) ; missing or empty - routley. " section 3 : the age of luther ". christian hymns ( audio book ), op. cit. - routley. the music of christian hymns, op. cit. p. 28. - ibid. p. 29. - ibid. p. 29. - " section 5, the psalmody of calvin ' s geneva ". christian hymns ( audio book ), op. cit. unknown parameter - routley. the music of christian hymns, op. cit. p. 35. - routley. the music of christian hymns


calvin ' s geneva ". christian hymns ( audio book ), op. cit. unknown parameter - routley. the music of christian hymns, op. cit. p. 35. - routley. the music of christian hymns, op. cit. pp. 36 – 37. - ibid. p. 38. - julian, john ( 1985 ). dictionary of hymnology. grand rapids : kregel publications. pp. 863 – 864. isbn 0 - 8254 - 2960 - 9. unknown parameter | subject entry = ignored ( help ) - ibid. p. 864b. unknown parameter | subject entry = ignored ( help ) - stone, alfred ( 1891 ). the bristol tune book ( third edition ed. ). london, uk, new york, ny : novello, ewer & co. - raymond f. glover, ed., the hymnal 1982 companion, four volumes, the church hymnal corporation, new york, 1990. - franz hildegrandt and oliver a. beckerlegge, eds., the works of john wesley, volume 7 : a collection of hymns for the use of the people called methodists, oxford university press, 1983. includes appendix j : wesley ' s tunes for the collection, 1786. - john julian, a dictionary of hymnology, 2 vols., dover publications, new york, 1957. - d. dewitt wasson, hymntune index and related hymn materials, three volumes, scarecrow press, lanham, maryland, 1998. - erik routley, the music of christian hymns, gia publications, chicago, il, 1981. - austin c. lovelace, the anatomy of hymnody, gia publications, chicago, il, 1965.


naval station norfolk | | this article needs additional citations for verification. ( april 2008 ) | | naval station norfolk | naval station norfolk in june 2009 | | iata : ngu – icao : kngu – faa lid : ngu | | airport type | | military : naval station | | operator | | united states navy | | location | | norfolk, virginia, u. s. | | occupants | | u. s. fleet forces command | naval station norfolk ( iata : ngu, icao : kngu, faa lid : ngu ), in norfolk, virginia, is a base of the united states navy, supporting naval forces in the united states fleet forces command, those operating in the atlantic ocean, mediterranean sea, and indian ocean. ns norfolk, also known as the norfolk naval base, occupies about four miles ( 6 km ) of waterfront space and seven miles ( 11 km ) of pier and wharf space of the hampton roads peninsula known as sewell ' s point. it is the world ' s largest naval station, supporting 75 ships and 134 aircraft alongside 14 piers and 11 aircraft hangars, and houses the largest concentration of u. s. navy forces. port services controls more than 3, 100 ships ' movements annually as they arrive and depart their berths. air operations conducts over 100, 000 flight operations each year, an average of 275 flights per day or one every six minutes. over 150, 000 passengers and 264, 000 tons of mail and cargo depart annually on air mobility command ( amc ) aircraft and other amc - chartered flights from the airfield ' s amc terminal. the land on which the naval station is located was originally the site of the 1907 jamestown exposition. during this exposition, high - ranking naval officers agreed that this site was ideal for a naval activity. a bill was passed in 1908 proposing that the u. s. congress allow $ 1 million for the purchase of the property and buildings, but it died when the assistant secretary of the navy was given a choice between this property and a new coal ship. he replied that a new ship was an absolute necessity. however, immediately after the united states entered world war i in april 1917, the secretary of the navy was persuaded to buy the property. a bill was passed for the purchase of 474 acres ( 1. 9 km² ) ; it set aside the sum of $ 1. 2 million as payment for the property and an additional $ 1. 6 million for the development of the base, including piers, aviation facilities, storehouses, facilities for fuel and oil storage, a


) ; it set aside the sum of $ 1. 2 million as payment for the property and an additional $ 1. 6 million for the development of the base, including piers, aviation facilities, storehouses, facilities for fuel and oil storage, a recruit training station, a submarine base and recreation grounds for fleet personnel. rear admiral dillingham was assigned the task of coordinating the area ' s development. construction of the training camp began on independence day 1917, and within the first 30 days housing for 7, 500 men had been completed. the next six months saw the establishment of the 5th naval district headquarters and the naval operating base, which included the naval training center, naval air station, naval hospital and submarine station. by armistice day 1918, there were 34, 000 enlisted men at the base. when the available land became insufficient, a large part of the flats on the west and north were filled from dredging done to allow large ships to dock. during the fall and winter of 1917, approximately 8 million cubic yards ( 6, 000, 000 m³ ) of dredging took place. important historical events were taking place on the air side of the station as well. november 14, 1910 marked the birth of naval aviation when eugene ely, a pilot employed by the curtiss exhibition company, slowly accelerated toward the end of a 57 - foot ( 17 m ) wooden ramp constructed on the bow of the cruiser uss birmingham. the heavy cruiser was anchored in the james river, not too far from the site of the civil war ' s famous ironclad battle of hampton roads between the monitor and merrimac. nas norfolk started its roots training aviators at naval air detachment, curtiss field, newport news, on may 19, 1917. approximately five months later, with a staff increasing to five officers, three aviators, ten enlisted sailors and seven aircraft, the detachment was renamed naval air detachment, naval operating base, hampton roads. the aircraft, all seaplanes, were flown across the james river and moored to stakes in the water until canvas hangars were constructed. the new location offered sheltered water in an ice - free harbor, perfect for seaplane landings, good anchorage on the beach front, accessibility to supplies from naval station norfolk and room for expansion. its mission was to conduct anti - submarine patrols, train aviators and mechanics and run an experimental facility. world war i when the united states became involved in world war i, the size of the navy ' s air component was rapidly expanded. in the 19 months of u. s. participation, a force


aviators and mechanics and run an experimental facility. world war i when the united states became involved in world war i, the size of the navy ' s air component was rapidly expanded. in the 19 months of u. s. participation, a force of 6, 716 officers and 30, 693 enlisted served in naval aviation. the training of mechanics to support the aircraft began in january 1918 at the norfolk detachment and the first patrol was conducted five months later. by then, the air detachment was recognized as one of the most important sources of trained naval aviators. in recognition of its importance, on august 27, 1918, the detachment became naval air station hampton roads, a separate station under its own commanding officer, lt. cmdr. patrick n. l. bellinger. as world war i came to an end, the former nas hampton roads saw erratic growth, growing to nearly 167 officers, 1, 227 enlisted men and 65 planes. but, it was after the war that demobilization had threatened the future of naval aviation. within seven months of the war ' s end, navy manpower fell to less than half its wartime highs. the republican party rose to power in 1920, promising fiscal austerity. congress cut naval appropriations by 20 % and manpower navy - wide was reduced. the carriers which congress had authorized were impossible to man. after the 1929 stock market crash and the onset of the great depression, president herbert hoover favored more naval limitation through international conferences, but the air operations in norfolk continued. using the same theories of eugene ely ' s flight nearly 13 years earlier, another milestone was achieved. the air station developed an arresting device to train pilots for deck landings aboard the fleet ' s first aircraft carrier, uss langley. at the same time, the station also began work on the development of the catapult. in january 1923, the secretary of the navy ordered a detailed study of the capacity of the bases and stations during war and peace. in comparing the development of the fleet and shore establishments, only hampton roads met the requirements. lighter - than - air operations, important for off - shore patrols during the war, ceased in 1924. in an effort similar to base closure struggles the military has today, civilian employees of the assembly and repair department ( forerunner of the former naval air depot ) joined the norfolk chamber of commerce in successfully fighting the planned suspension of aircraft overhaul work. the training of air groups from newly commissioned aircraft carriers such as langley, saratoga and lexington demanded expansion, but appropriations were meager for shore establishments. during the 1920s


) joined the norfolk chamber of commerce in successfully fighting the planned suspension of aircraft overhaul work. the training of air groups from newly commissioned aircraft carriers such as langley, saratoga and lexington demanded expansion, but appropriations were meager for shore establishments. during the 1920s and ' 30s the naval station operated at a reduced operating tempo. the training component processed only 1, 600 individuals by the late 1920s. by 1927, the naval training station, whose primary mission was to operate 12 service schools and train new recruits, had been reduced considerably from its wartime status, training only 560 recruits at a command with triple that capacity. during the late 1930s, major construction took place at naval station norfolk. at this time, building k - bb ( naval station headquarters ), the galley, and many barracks were built. as the 1930s came to a close, the station also began to prepare for total war. by 1939, when the atlantic fleet returned to the east coast, the naval station was clearly the biggest naval installation on the atlantic coast. in april 1939, in something of a test, the naval station refueled, restocked, and returned to service 25 ships in one week. this force was but the prelude to about 100 ships converging on norfolk at the time. it included the battleships california, idaho and new mexico and the carriers, lexington, ranger, yorktown and enterprise. the expansion of shipboard aviation in the 1930s brought renewed emphasis to naval air station norfolk. reverting to its experimental roots, development and testing of catapult and arresting gear systems took the highest priority at the air station. the commissioning of the aircraft carriers ranger, yorktown, wasp, and hornet increased the tempo of routine training in navigation, gunnery and aerial bombing as new air wings formed prior to world war ii. this demanded expansion, but appropriations for shore activities were meager. although congressional approval was gained in 1934 for the purchase of land that would expand the airfield by 540 acres ( 2. 2 km² ), the matter was dropped. at the outbreak of war in europe on september 1, 1939, nas norfolk encompassed 236 acres ( 1. 0 km² ) with two small operating areas, chambers field and west landing field. during world war ii, the naval air station had a direct combat support role in the area of anti - submarine patrols. president franklin d. roosevelt ' s response to the start of the war in europe was the national emergency program of september 8, 1939. it resulted in fantastic growth for all navy activities in the norfolk area. the combat support role


anti - submarine patrols. president franklin d. roosevelt ' s response to the start of the war in europe was the national emergency program of september 8, 1939. it resulted in fantastic growth for all navy activities in the norfolk area. the combat support role began on october 21, 1939, when a 600 - mile ( 970 km ) - wide neutrality zone was declared around the american coast. four norfolk - based patrol squadrons, vp - 51, us vp - 52, vp - 53 and vp - 54 were among the first units to enforce the zone. world war ii world war ii profoundly changed the appearance of the naval station. with the eruption of war in europe in september 1939, the station began to vibrate with activity. by december, the navy had over $ 4 million in projects underway on the station. by the summer of 1940 the station employed some 8, 000 personnel, a number larger than any time since the end of world war i. the hepburn board had made recommendations to congress earlier in the year that would also double the size and workload of the station. since chambers and west fields were encroaching on the activities of the former naval operating base, it was decided to expand to the east. east camp, with an area of about 1, 000 acres ( 4 km² ) between the east side of naval station and granby street, had been sold off by the army at the end of world war i. congress authorized its repurchase in early 1940. on june 29 of that year, a contract was signed with the virginia engineering company of newport news for the expansion of the station. the cost of expansion and construction was to reach more than $ 72 million. hangars, a new dispensary, three runways, magazine areas, warehouses, barracks and docking areas were patterned after similar existing airfields. the plan was revised and approved by captain p. n. l. bellinger, returning as commanding officer 20 years after first holding the job. bellinger insisted that as many structures as possible be permanent ones. the air station was still largely composed of temporary hangars and workshops left over from world war i. many were unsafe and costly to maintain. the last permanent structure added had been the administration building, constructed in 1930. special attention was paid to control facilities. prior to the expansion, operations from chambers field had no traffic control system except for a white placard inserted through a slot on the roof to indicate the direction of the runway in use. some 353 acres ( 1. 4 km² ) were eventually reclaimed


to the expansion, operations from chambers field had no traffic control system except for a white placard inserted through a slot on the roof to indicate the direction of the runway in use. some 353 acres ( 1. 4 km² ) were eventually reclaimed at a cost of $ 2. 1 million. two large hangars and ramps for seaplanes, barracks, officer quarters and family housing were built. this construction cut off mason creek road and the navy compensated the city by improving kersloe road between hampton boulevard and granby street. norfolk responded by renaming the road, admiral taussig boulevard, in honor of the retiring commander of the naval operating base. in july 1940, the federal government began dredging willoughby bay and the naval air station seaplane operating area at breezy point, virginia was constructed from reclaimed marshlands at the mouth of mason creek, virginia. by the time president roosevelt visited at the end of july, the station was clearly reaching the point where it could support ships engaged in war overseas. in 1941, the possibility of u. s. involvement in the war looked more likely. construction of more new facilities was pushed forward to match increased requirements. directives from washington meant facilities had to be developed to operate five aircraft carrier air groups, seven to nine patrol squadrons, the fighter director school and the atlantic fleet operational training program for 200 pilots prior to their fleet assignment. further requests were made to provide training and maintenance facilities for british aircrew from hms illustrious and formidable. in june 1941, the personnel count at the naval station dramatically increased once again. there were now about 10, 000 new recruits at the naval training station, 15, 559 officers and enlisted on station, and 14, 426 sailors assigned to ships homeported in norfolk. after pearl harbor, another $ 4 million was put into the receiving station to elevate its capacity by some 5, 500 individuals. the navy planned to double hospital capacity, as well as adding a full range of indoor and outdoor athletic facilities to go along with the construction of a new auditorium. in all, these new requirements led to enlarging the construction project to five times its original scope. at the completion of the first round of construction, east field was estimated to have the capacity for 410 land planes while breezy point ' s capacity was estimated at 72 seaplanes. from a manpower viewpoint, nas norfolk grew from an average of 2, 076 officers and enlisted in december 1940 to 16, 656 active duty in december 1943. for the first six months of 1943,


s capacity was estimated at 72 seaplanes. from a manpower viewpoint, nas norfolk grew from an average of 2, 076 officers and enlisted in december 1940 to 16, 656 active duty in december 1943. for the first six months of 1943, the flight operations department recorded an average of 21, 073 flights per month and an average of 700 flights per day. this represents a take - off or landing every two minutes, 24 hours a day. the increased pace of operations made it necessary to further physical plant growth. in order to extend runways and provide more parking areas, an additional 400 acres ( 1. 6 km² ) including the old norfolk airport were acquired. finally, by 1943, the naval air station had become the hub for a series of outlying airfields. facilities were commissioned at chincoteague, whitehurst, reservoir, oceana, pungo, fentress, monogram, and creeds, va., as well as elizabeth city, edenton, manteo, and harvey point, n. c. a new command, naval air center, had been formed october 12, 1942 under captain j. m. shoemaker, the 15th and 18th commanding officer of nas norfolk, to coordinate operations within the norfolk area. the outlying fields were used for training, patrol plane operations, practice bombing and aerial gunnery. the assembly and repair ( a & r ) department also offers an excellent example of expansion at the naval air station. in 1939, a & r occupied four world war i hangars and a few workshops. it employed 213 enlisted men and 573 civilians in the overhaul of aircraft engines and fuselages. in 1940, the naval aircraft program passed congress with a production goal of 10, 000 new planes later increased 15, 000. to support this effort, a & r, after pearl harbor, went to two 10 - hour shifts per day, seven days a week for a work force that now numbered 1, 600 enlisted and 3, 500 civilians. women, who had been employed only as seamstress for wing and fuselage fabric, began working in a & r machine shops as labor shortages became acute. during the summer of 1942, the apprentice school was opened to provide training in nine trades. by war ' s end, assembly and repair had developed into a class " a " industrial plant with peak employment of 3, 561 civilians and 4, 852 military workers. after war was formally declared following pearl harbor, germany began a u - boat offensive, " operation drumbeat ", against shipping along the atlantic coast


a " industrial plant with peak employment of 3, 561 civilians and 4, 852 military workers. after war was formally declared following pearl harbor, germany began a u - boat offensive, " operation drumbeat ", against shipping along the atlantic coast. the eastern sea frontier, a command headquartered in new york, directed the american response. locally, fleet air wing 5 units flew under its operational command of the 5th naval district. wing 5 units involved consisted of scouting squadrons, 12 os2u kingfisher seaplanes and vps 83 and 84 equipped with pby5a catalinas. by 1942, nas norfolk was home to 24 fleet units. in this early phase of the war, the u - boats had the best of it. with a peacetime mindset still prevalent, valuable ships sailed independently — backlit by the lights of seaside towns. from january through april 1942, the eastern sea frontier recorded 82 sinkings by u - boats. during the same period, only eight u - boats were sunk by u. s. forces. eventually, coastal convoys were instituted and more aircraft became available. german u - boats moved elsewhere and sinkings decreased. to move closer to their patrol areas and free up space for the training of new squadrons, nas norfolk - based patrol squadrons transferred their operations from breezy point to chincoteague and elizabeth city. nas norfolk ' s biggest contribution to the winning of world war ii was in the training it provided to a wide variety of allied naval air units. at the start of the war, training activities at nas did not fall under the direction of a single overseer. this changed on january 1, 1943 with the creation of commander air force atlantic fleet with rear admiral ( later vice admiral ) bellinger in charge. the former nas commanding officer was tasked with providing administrative, material and logistic support for atlantic fleet aviation units. airlant also furnished combat - ready carrier air groups, patrol squadrons and battleship and cruiser aviation units for both the atlantic and pacific fleets. to complete this task, fleet air wing 5 in norfolk turned over its operational commitments for the eastern sea frontier to fleet air wing 9 at nas quonset point, rhode island. in december 1942, recruit training at the base was abolished since the base was now more suitably equipped for advanced training for men going directly to the fleet. with the change in the training station and the declaration of war, the mission became that of a pre - commissioning training station. three 1, 000 foot ( 300 m ) piers, which were used as convoy


training for men going directly to the fleet. with the change in the training station and the declaration of war, the mission became that of a pre - commissioning training station. three 1, 000 foot ( 300 m ) piers, which were used as convoy escort piers, were built during world war ii. on september 18, 1943, faw - 5 assumed the primary mission of providing training under the direction of airlant. the aviation service school offered courses in metalsmith work, engine repair, radio repair and ordnance. aviation machinist ' s mate a school consisted of two months of training and two months of practical experience in a & r department shops. the advanced base aviation training unit helped sailors develop the skills necessary to maintain all types of aircraft at advanced bases in combat area. the aircraft they completed went to the fleet pool for distribution to squadrons in the process of commissioning. a similar service for maintenance crews in squadrons awaiting the commissioning of new carriers was provided by the carrier air service unit. among the earliest schools at nas was the fighter director school, which taught fleet communications and tactics, radar operations and direction of aircraft from ships before moving to georgia. the celestial navigation training unit instructed pilots being assigned to patrol squadrons. the aerial free gunnery training unit was originally located at breezy point, but moved to dam neck in 1943 to be able to carry out range work without restricting airspace. carrier qualifications training unit provided for field carrier landing practice, simulated carrier search techniques and qualification landings. any carriers available in hampton roads were used to deck - qualify pilots, but the bulk of the load went to uss charger. for most of the war, charger acted as school ship both for squadrons in training and for flight deck personnel assigned to newly commissioned carriers. the air station ' s impact on winning world war ii was more extensive than most people think. with only a few exceptions, all navy air squadrons that fought in the war trained in norfolk. the air station also trained numerous british fighter squadrons and french and russian patrol squadrons. from 1943 to the end of the war, a total of 326 u. s. units were commissioned and trained under the control of airlant. undoubtedly, the loudest noise heard and one of the most devastating navy accidents in hampton roads during world war ii occurred at 11 am september 17, 1943. a nas ordnance department truck was pulling four trailers loaded with depth charges on the taxiway between nas and the nob piers. each trailer was designed to carry four aerial depth charges. to save time, two additional charges were loaded on top


, 1943. a nas ordnance department truck was pulling four trailers loaded with depth charges on the taxiway between nas and the nob piers. each trailer was designed to carry four aerial depth charges. to save time, two additional charges were loaded on top of each trailer. compounding the problem, the charges on top were not properly chained down. one of the charges slipped loose and became wedged between the trailer and the ground. the friction of being dragged against the road caused the charge to begin smoking. an alert marine sentry spotted the smoke and notified the driver who immediately stopped the truck and ran to a nearby fire station. assistant fire chief gurney e. edwards hurried to the scene and attempted to cool down the charges with a fire extinguisher. as soon as he started his attempt, the first depth charge exploded, killing him instantly. for several minutes, charges continued to explode. the blasts shattered windows up to seven miles ( 11 km ) away ( 10 km ) and were heard in suffolk, 20 miles ( 30 km ) distant. in the center of the explosion was a group of old enlisted men ' s barracks opposite the dispensary, the vicinity of the current location of v - 88. a total of 18 buildings were destroyed by the blast. they were so badly damaged that they had to be razed. thirty - three aircraft were also destroyed with a monetary damage of $ 1. 8 million. according to official histories, the shock of the explosion found people scaling fences that had been considered man - proof and impossible to climb. other persons found themselves some time later with shoes in hand, waiting for street cars, with no memory of the event. the casualties amounted to 426, including 40 dead. among them was seaman 2nd class elizabeth korensky, the only woman killed and the first wave to die in the line of duty in the war. nas norfolk responded to the tragedy by building six new brick barracks to house the troops and added industrial space by building r - 80, the largest airplane hangar in the world. winning the war was a full - time effort. postwar period developments underscored the capacity of the naval station to change. the station at first stored inactive aircraft carriers, other reserve vessels, and finally submarines and destroyers. fire fighting and salvage control now became specialties. the atlantic fleet command came ashore in 1948 and placed its headquarters with a staff of 165 officers and 315 enlisted in an abandoned hospital. at the same time, the station rendered service to military as well as scientific pursuits. known officially as naval


specialties. the atlantic fleet command came ashore in 1948 and placed its headquarters with a staff of 165 officers and 315 enlisted in an abandoned hospital. at the same time, the station rendered service to military as well as scientific pursuits. known officially as naval operating base until 31 december 1952, on january 1, 1953 the name of the installation was changed to naval station norfolk. after the second world war, the air side of the station continued to operate at near peak levels as well. it served as operational headquarters for the fleet air command, and with the emergence of nas oceana as a master jet base in the late 1950s, the tandem formed the nucleus of the biggest air base on the east coast. the airfield was renamed as naval air station norfolk ( chambers field ) and would remain so throughout the postwar period through the end of the cold war. in 1967 it came under the control of commander, naval air force, atlantic ( comnavairlant ). the norfolk facility remained the chief supplier of aircraft parts and a major rework plant. classified as " industrial ", the station employed about 7, 500 civilians in 1946. in one postwar year the navy invested $ 36 million in the overhaul and repair plant alone. the average annual payroll in the last had of the 1950s came to nearly $ 45 million. by 1976, the air rework plant covered 174 acres ( 0. 7 km² ) and included 175 buildings. in the 1970s and 1980s its workers restored or repaired, among other craft, f - 14 tomcats, a - 6 intruders, and f - 8 crusaders. from june 1980 until june 1981, the air station handled over 135, 478 aircraft operations, 29, 832 tons of air cargo, and 132, 000 passengers. in 1996, as part of the congressional " base realignment and closure " ( brac ) process this plant, known by this time as the naval aviation depot norfolk, closed its doors. the air station, at one time, was host to more than 70 tenant commands, including several carrier groups, a carrier airborne early warning wing and associated squadrons, a helicopter sea control wing and associated squadrons, and various naval air reserve units, primarily the wing headquarters for reserve patrol wing atlantic, the local headquarters for naval air reserve norfolk and reserve e - 2 hawkeye, c - 9 skytrain ii and various helicopter squadrons. a marine corps reserve medium helicopter squadron with ch - 46 sea knight aircraft was also assigned. in addition, the air station rendered support in photography, meteorology, and electronics to the fleet


for other places with the same name, see la paz ( disambiguation ) la paz is the administrative capital of bolivia, while sucre is the constitutional capital and the seat of the supreme court. la paz was established in 1548, and is in the andes. altitude of the city ranges from about 4, 058 m ( 13, 313 ft ) above sea level in el alto ( where the airport is located ) to 3, 100 m ( 10, 170 ft ) in the lower residential area. it is the highest national capital in the world. the sight from the air as one flies into la paz is incredible. first, one sees the sprawling shantytowns of el alto, slowly giving way to the sight of la paz itself, clinging tenuously to the sides of what looks like a large gash in the earth. la paz was built in a canyon created by the choqueyapu river ( now mostly built over ), which runs northwest to southeast. the city ' s main thoroughfare, which roughly follows the river, changes names over its length, but the central tree - lined section running through the downtown core is called the prado. la paz geography, in particular the altitude, reflects the city ' s society : the lower you go, the more affluent. while many middle - class pacenos live in high - rise condos near the center, the really rich houses are located in the lower neighborhoods southwest of the prado. the reason for this division is that the lower you go in the city the milder the weather is. and looking up from the center, the surrounding hills are plastered with makeshift brick houses of those struggling in the hope of one day reaching the bottom. the satellite city of el alto, in which the airport is located, is spread over a broad area to the west of the canyon, on the altiplano. el alto international airport ( iata : lpb ) ( icao : sllp ), el alto. this is the world ' s highest international airport ; at 13, 313 ft / 4, 058 m above sea level, it ' s almost half as high as a jetliner ' s cruising altitude, and takeoffs require a longer runway due to the thin air. there is an airport departure tax of us $ 25 for international flights, bs. 15 ( around us $ 2 ) for domestic flights. tax can only be paid in cash, but several atms which also give out us $ are available at the airport. most south american airlines ( lan,


$ 25 for international flights, bs. 15 ( around us $ 2 ) for domestic flights. tax can only be paid in cash, but several atms which also give out us $ are available at the airport. most south american airlines ( lan, taca, avianca, skyairline etc. ) serve el alto airport as well local airlines ( boliviana de aviacion ( boa ), transporte aereo militar ( tam ), aerocon and amaszonas ). most international flights will make a stop over in santa cruz to pick up or drop off passengers. american airlines is currently the only u. s. carrier serving bolivia, with one daily flight from miami. state - funded boliviana de aviacion ( boa ) and tam ( usually for a cheaper price ) serve major domestic destinations as well as some major south american hubs. aerocon mainly provides air links to communities in the beni department via their hub trinidad. amaszonas provides direct service to tourist destinations like rurrenabaque or uyuni. lab ( lloyd aereo boliviano ) was bolivia ' s national airline until april 2007, when services were suspended by the bolivian government due to financial problems. while you may be in the practice of racing to immigration when you get off a plane, in order to avoid long queues, forget about this in la paz. take things very easily or you will be seriously out of breath and may suffer medical complications. just walk slowly to the immigration area. from the airport, the official rate for a taxi into central la paz is bs 60 ( about us $ 9 ). only use radio taxis with a sign on the roof. shared vans cost bs 3. 80 ( us $ 0. 50 ). when returning to the airport, please give yourself plenty of time if taking the bus. often they are full once they pass near plaza san francisco, especially during rush hour 5 - 7pm. the first bus leaves from plaza isabel de catolica in sopocachi at 6. 15 a. m. if you are taking a tam flight out of la paz airport be very careful to verify which airport it is leaving from, some tam flights leave from the el alto intl airport and others from the military base airport. i got mistakenly dropped off early morning by the taxi driver at the military airport which is about 2 km from the intl airport and had no choice but to catch a cab back for the ripoff price for 30 bs ( for 2 km


base airport. i got mistakenly dropped off early morning by the taxi driver at the military airport which is about 2 km from the intl airport and had no choice but to catch a cab back for the ripoff price for 30 bs ( for 2 km! ) as it was early morning! ( as of nov. 2011 all tam flights seem to be leaving from el alto intl. - may 2012 update - tam flights do sometimes still leave from the military airport ) the main bus terminal is in central park, near the upper end of the prado and a 15 - 20 min walk from most hostels. from this bus station, buses leave for big cities such as cochabamba, santa cruz, oruro, potosi, sucre, tarija and arica. buses leaving la paz usually stop in el alto to pick up more passengers. it sometimes takes almost an hour until you really leave the city. cochabamba 7 - 8 hr. normal day buses cost around bs 20 while " full cama " ( flat bed ) buses with for example bolivar cost bs 90. semi cama between the two. oruro 3 hr, bs 15. to chile, buses run to arica, around 8 hr, some continuing to iquique ( 12 - 14 hr - best to get the bus at 7am, later buses will result in arriving in iquique in the middle of the night. ) buses departing to, and arriving from, lake titicaca, like copacabana, sorata, desaguadero, tiwanaku and so on leave from the area " cementerio " ( the city cemetery ). buses are leaving from " parada copacabana ", " parada sorata ", " parada desaguadero " in the " cementerio " - area. buses going towards quime, any bus going to oruro from the main bus terminal will stop in conani, from whence you catch a mini - van into the cordillera de quimsa cruz. there are three types of shared public transportation in la paz : regular buses or " micros " ; shared vans, called " mini buses ", and shared taxis running set routes advertised on the windshield, called " trufis ". the former cost bs 1, 30 while the second are bs 1, 50 - 2, 30 depending on duration. a trufi will generally cost you bs 3 - 3. 50. all types have their routes indicated on the windshield, but