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earth_science-33/extraction_0.txt | Air temperatures on Earth have been rising since the Industrial Revolution. While natural variability plays some part, the preponderance of evidence indicates that human activities—particularly emissions of heat-trapping greenhouse gases—are mostly responsible for making our planet warmer. According to an ongoing tempe... | |
earth_science-33/extraction_1.txt | The likely range of human-induced warming in global-mean surface air temperature (GSAT) in 2010–2019 relative to 1850–1900 is 0.8°C–1.3°C, encompassing the observed warming of 0.9°C–1.2°C, while the change attributable to natural forcings is only −0.1°C to +0.1°C. The best estimate of human-induced warming is 1.07°C. W... | |
earth_science-33/extraction_3.txt | Over the historical period, changes in aerosols and their effective radiative forcing (ERF) have primarily contributed to a surface cooling, partly masking the greenhouse gas-driven warming (high confidence). Radiative forcings induced by aerosol changes lead to both local and remote temperature responses (high confide... | |
earth_science-33/extraction_4.txt | The following was contributed by **Dr. Clara Deser**, NCAR, December, 2015: The Pacific Decadal Oscillation (PDO), first defined by Mantua et al. (1997), is the dominant year-round pattern of monthly sea surface temperature (SST) anomalies in the North Pacific obtained via Empirical Orthogonal Function (EOF) analysis. ... | |
earth_science-33/extraction_5.txt | # Why did climate cool in the mid-20th Century? ## What the science says... | | | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | | Select a level... | **Basic** | | \<br> Intermediate | | \<br> Advanced | | | | Mid-century cooling involved aerosols and is irrelevant for recent global warming. | ## Climat... | |
earth_science-33/extraction_6.txt | # NEWS & VlEWS CLIMATE CHANGE # Hot questions of temperature bias Chris E. Forest and Richard W. Reynolds An unseen measurement bias has been identified in global records of sea surface temperature. The discrepancy will need correction, but will not affect conclusions about an overall warming trend. On page 646 of this... | |
subducted_plate/Intermontane_Islands1.txt | part1 -------------------
The Intermontane Islands were a giant chain of active volcanic islands somewhere in the Pacific Ocean during the Triassic time beginning around 245 million years ago. They were 600 to 800 miles (1,300 km) long and rode atop a microplate known as the Intermontane Plate. Over early Jurassic tim... | |
subducted_plate/Intermontane_Plate2.txt | part2 -------------------
Collision of the Intermontane Islands[edit]
During the early Jurassic period, the Intermontane Islands and the Pacific Northwest drew closer together as the continent moved west and the Intermontane Microplate subducted. On the continent, subduction supported a new volcanic arc that again sent... | |
subducted_plate/Intermontane_Plate1.txt | part1 -------------------
The Intermontane Plate was an ancient oceanic tectonic plate that lay on the west coast of North America about 195 million years ago. The Intermontane Plate was surrounded by a chain of volcanic islands called the Intermontane Islands, which had been accumulating as a volcanic chain in the Pac... | |
earth_science-34/extraction_0.txt | Plate-tectonic movements since the break-up of the supercontinent Pangaea are now fairly well understood. Most scientists believe that similar processes must also have occurred earlier. However, the pre-Pangaea history of plate tectonics is very difficult to decipher, because nearly all of the evidence has been obscure... | |
earth_science-34/extraction_1.txt | ## 1\. Introduction Seismic tomography has provided a breakthrough in the analysis of plate tectonic history by allowing to trace now-subducted ancient lithosphere in the Earth's mantle, where they appear as plate-like positive seismic wave-speed anomalies in the upper mantle and often more amorphous structures in the ... | |
earth_science-34/extraction_2.txt | Welcome to the website of The Atlas of the underworld – the first complete mapping of subducted plates in the Earth’s mantle and their geological interpretation. The Earth’s rigid outer shell – the lithosphere – is broken into plates that move relative to one another along discrete plate boundaries – ridges, transforms... | |
earth_science-34/extraction_8.txt | ## Abstract Across the entire mantle we interpret 94 positive seismic wave-speed anomalies as subducted lithosphere and associate these slabs with their geological record. We document this as the _Atlas of the Underworld_, also accessible online at www.atlas-of-the-underworld.org, a compilation comprising subduction sy... | |
earth_science-34/extraction_9.txt | ## _Convergent boundaries_ The size of the Earth has not changed significantly during the past 600 million years, and very likely not since shortly after its formation 4.6 billion years ago. The Earth's unchanging size implies that the crust must be destroyed at about the same rate as it is being created, as Harry Hess... | |
using_accelerometer_as_a_seismograph/Peak_ground_acceleration2.txt | part2 -------------------
Geophysics[edit]
Earthquake energy is dispersed in waves from the hypocentre, causing ground movement omnidirectionally but typically modelled horizontally (in two directions) and vertically. PGA records the acceleration (rate of change of speed) of these movements, while peak ground velocity ... | |
using_accelerometer_as_a_seismograph/Peak_ground_acceleration4.txt | part4 -------------------
Comparison of instrumental and felt intensity[edit]
Peak ground acceleration provides a measurement of instrumental intensity, that is, ground shaking recorded by seismic instruments. Other intensity scales measure felt intensity, based on eyewitness reports, felt shaking, and observed damage.... | |
using_accelerometer_as_a_seismograph/Richter_scale5.txt | part5 -------------------
Magnitude empirical formulae[edit]
These formulae for Richter magnitude
M
L
{\displaystyle \ M_{\mathsf {L}}\ }
are alternatives to using Richter correlation tables based on Richter standard seismic event
(
M
L
=
0
,
{\displaystyle {\big (}\ M_{\mathsf {L}... | |
using_accelerometer_as_a_seismograph/Peak_ground_acceleration1.txt | part1 -------------------
Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. Earthquake shaking generall... | |
using_accelerometer_as_a_seismograph/Richter_scale2.txt | part2 -------------------
Richter magnitudes[edit]
The Richter magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are included to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquake. T... | |
earth_science-35/extraction_1.txt | 2.5.1 Converting from Peak Acceleration and Velocity to Instrumental Intensity Wald and others (1999b) recently developed regression relationships between Modified Mercalli intensity I mm (Wood and Neumann, 1931, later revised by Richter, 1958) and PGA or PGV specifically for ShakeMap use by comparing the peak ground-m... | |
earth_science-35/extraction_8.txt | What is the difference between earthquake magnitude and earthquake intensity? What is the Modified Mercalli Intensity Scale? ============================================================================================================================ Magnitude scales, like the moment magnitude, measure the size of the e... | |
aurora/Aurora1.txt | part1 -------------------
An aurora (pl. aurorae or auroras),
also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of... | |
earth_science-36/extraction_0.txt | ## Discover the Physics of Auroras - ### Magnetospheres and Geomagnetic Storms Many planets, including Earth, are surrounded by a large magnetic shield called a **magnetosphere**. On Earth, this shield stems from the churning molten metal core inside the planet and extends far out into space. Our magnetosphere protects... | |
earth_science-36/extraction_1.txt | # Aurora !Aurora Aurora The Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights) are the result of electrons colliding with the upper reaches of Earth’s atmosphere. (Protons cause faint and diffuse aurora, usually not easily visible to the human eye.) The electrons are energized through acceleration... | |
earth_science-36/extraction_2.txt | **9. The Polar Aurora** _Fritz_ \[1881; _Eather_, 1980\] estimated that, given clear skies, aurora could be observed about 100 nights a year in the region where it was most frequent. However, imaging cameras aboard satellites, more sensitive than the eye, observe a ring of diffuse aurora around the polar cap at most ti... | |
earth_science-36/extraction_3.txt | ### **What is the Aurora?** Aurora is the name given to the glow or light produced when electrons from space flow down Earth’s magnetic field and collide with atoms and molecules of the upper atmosphere in a ring or oval centered on the magnetic pole of Earth. The collisions produce light much like how electrons flowin... | |
earth_science-36/extraction_4.txt | ### What causes the light that we call the aurora: The light in the upper atmosphere is caused by energetic electrons zipping down the magnetic field lines of Earth and colliding with the atoms and molecules of the atmosphere (primarily O and N2). When the electrons collide with the atmosphere, they transfer momentum e... | |
earth_science-36/extraction_6.txt | ## Abstract \[1\] During 2001 and 2002, when the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite had its apogee in the Northern Hemisphere and the Polar spacecraft, owing to the apsidal precession of its orbit, reached higher altitudes in the Southern Hemisphere, the two spacecraft offered a uniq... | |
earth_science-36/extraction_7.txt | ## Abstract The solar-wind magnetosphere interaction primarily occurs at altitudes where the dipole component of Earth’s magnetic field is dominating. The disturbances that are created in this interaction propagate along magnetic field lines and interact with the ionosphere–thermosphere system. At ionospheric altitudes... | |
earth_science-36/extraction_9.txt | # ABSTRACT Auroral studies have shown that there are systematic displacements and significant intensity differences of the aurora in the two hemispheres. Such observations have been systematically correlated with the various components of the interplanetary magnetic field (IMF) and hemispherical differences in solar ex... | |
earth_science-36/extraction_10.txt | WASHINGTON — For many years, scientists assumed the aurora seen around the north pole was identical to the aurora seen around the south pole. The poles are connected by magnetic field lines and auroral displays are caused by charged particles streaming along these field lines. Because the charged particles follow these... | |
rifting/Madagascar_Plate1.txt | part1 -------------------
The Madagascar Plate or Madagascar block is a tectonic plate holding the island of Madagascar. It was once attached to the Gondwana supercontinent and later the Indo-Australian Plate.
Rifting in the Somali Basin began at the end of the Carboniferous 300 million years ago, as a part of the Karo... | |
rifting/Madagascar_Plate3.txt | part3 -------------------
Rifting[edit]
The Madagascar plate experienced two major rifting events during the break-up of Gondwana. First, it separated from Africa about 160 Mya (million years ago), then from the Seychelles and India 66–90 Mya.
The first rifting event, separation from Somalia and the rest of Africa, cau... | |
earth_science-37/extraction_0.txt | 1. Introduction ---------------- The Central Atlantic Magmatic Province (CAMP) is one of the largest Large Igneous Provinces on Earth. It was emplaced at ca. 201 Ma, close to the Triassic–Jurassic boundary, during the early stages of the breakup of the supercontinent of Pangaea that led to the opening of the Central At... | |
earth_science-37/extraction_1.txt | Timing and geometry of early Gondwana breakup ============================================= Wilfried Jokat , Wilfried Jokat * jokat@awi-bremerhaven.de Alfred Wegener Institute for Polar Research, Bremerhaven, Germany Tobias Boebel , Tobias Boebel Alfred Wegener Institute for Polar Research, Bremerhaven, Germany Matthia... | |
earth_science-37/extraction_2.txt | Abstract.The South Atlantic rift basin evolved as a branch of a large Jurassic–Cretaceous intraplate rift zone between the African and South American plates during the final break-up of western Gondwana. While the relative motions between South America and Africa for post-break-up times are well resolved, many issues p... | |
earth_science-37/extraction_3.txt | ABSTRACT A U±Pb zircon age of 91.2+0.2 Myr from western India (St. Mary islands) confidently links India with the Late Cretaceous magmatic province in Madagascar (&84±92 Ma), and the U±Pb age is within analytical error of the U±Pb age of the Analalava gabbro pluton (91.6+0.3 Myr) in northeastern Madagascar. Palaeomagne... | |
earth_science-37/extraction_4.txt | Palaeogeography --------------- edit The final stages of the breakup of Pangaea occurred during the Paleogene as Atlantic Ocean rifting and seafloor spreading extended northwards, separating the North America and Eurasian plates, and Australia and South America rifted from Antarctica , opening the Southern Ocean . Afri... | |
earth_science-37/extraction_5.txt | The NGS was initiated during the Jurassic as an intracratonic seaway separating Greenland from Norway[24]. This incipient NGS persisted into the early Eocene, during which time lithospheric breakup commenced between the East Greenland Fracture Zone in the north and the southern tip of Greenland (around chron C24n.3n 54... | |
earth_science-37/extraction_6.txt | Abstract -------- The warmest global temperatures of the past 85 million years occurred during a prolonged greenhouse episode known as the Early Eocene Climatic Optimum (52–50 Ma). The Early Eocene Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica f... | |
earth_science-37/extraction_7.txt | 1. Introduction The opening of the main Southern Ocean gateways, Drake Passage and the Tasmanian gateway separating South America and Australia from Antarctica respect- ively, enabled the present-day global ocean circulation pattern to develop (Kennett, 1977; Lawver, Gahagan, &Dalziel,2011; Livermore, Nankivell, Eagles... | |
earth_science-37/extraction_8.txt | Throughout the greater Red Sea rift system the initial late Cenozoic syn-rift strata and extensional faulting are closely associated with alkali basaltic volcanism. Older stratigraphic units are either pre-rift or deposited during pre-rupture mechanical weakening of the lithosphere. The East African superplume appeared... | |
salt_pits/Exercise_Ions_&_Solutions_Salt_Farming2.txt | San Francisco Bay Salt Ponds:
Due to variable algal concentrations, vivid colors, from pale green to bright red, are created in the evaporation ponds. The color indicates the salinity of the ponds. Micro-organisms change their hues as the salinity of the pond increases. In low to mid-salinity ponds, green algae ... | |
earth_science-38/extraction_0.txt | Before humans started building settlements and cities along the shores of San Francisco Bay, one of the world’s largest estuaries was surrounded by some of the world’s most extensive wetlands. Tidal marshes around the Bay served as natural water filters, with vegetation and shellfish improving the water quality by draw... | |
earth_science-38/extraction_1.txt | ### Solar salterns _Dunaliella_ was first spotted in saltern evaporation and crystallizer brines \ [1\]-\ [3\],\ [29\] and relatively much information is available about the occurrence of the genus in salterns worldwide \ [51\]-\ [55\]. In crystallizer ponds, _D. salina_ is found in numbers that vary from ~150 to ~3000... | |
earth_science-38/extraction_2.txt | _**Halobacterium salinarum**_, formerly known as _**Halobacterium cutirubrum**_ or _**Halobacterium halobium**_, is an extremely halophilic marine obligate aerobic archaeon.[\[2\]](https://en.wikipedia.org/wiki/Halobacterium_salinarum?utm_source=chatgpt.com#cite_note-MicrobioJ-2) Despite its name, this is not a bacteri... | |
earth_science-38/extraction_3.txt | ### 5\. Production of Carotenoids by Haloarchaea ### 5.1. Type, Content and Biosynthesis of Haloarchaeal Carotenoids Halophilic archaea are extreme halophilic microorganisms mainly grouped into the _Haloferacaceae_ family, phylum _Euryarchaeota_, _Archaea_ domain. They are (mostly) aerobic and generally red-pigmented. ... | |
earth_science-38/extraction_4.txt | **Gypsum** is a mineral that, on Earth, forms when sulfate- and calcium-rich salt water evaporates. One of the key reasons Curiosity is working in Gale Crater is that scientists suspect the sediment mound at its center contains gypsum—the product of an ancient lake when Mars was a much warmer, wetter place. In 2005, th... | |
methane_clathrates/BF001445042.txt |
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methane_clathrates/BF001445043.txt | AbstractMethane clathrates are stable at depths greater than about 200 m in permafrost regions and in ocean sediments at water depths greater than about 250 m, provided bottom waters are sufficiently cold. The thickness of the clathrate stability zone depends on surface temperature and geothermal gradient. Average stab... | |
earth_science-39/extraction_0.txt | ## USGS Estimates 53.8 Trillion Cubic Feet of Natural Gas Hydrate Resources in the Alaska North Slope ### New Geologically Based Assessment Estimates 53.8 Trillion Cubic Feet of Recoverable Natural Gas Resources By Communications and Publishing September 10, 2019 Access to 3D seismic mapping, along with a greater under... | |
earth_science-39/extraction_1.txt | 7 Methane Hydrates Gas hydrates are solid, ice-like substances made of water cages stabilized by gas molecules through van der Waals-type (weak, charge-based) attraction. Since the main gas is CH4, gas hydrates are often referred to as methane hydrates or clathrates: the general name for structured cage-like substances... | |
solid_inner_core/Earth%27s_inner_core1.txt | part1 -------------------
Earth's inner core is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 20% of Earth radius or 70% of the Moon's radius.
There are no samples of Earth's core accessible for direct measurement, as there are f... | |
solid_inner_core/Phase_diagram3.txt | part3 -------------------
Types[edit]
2-dimensional diagrams[edit]
Pressure vs temperature[edit]
A typical phase diagram. The solid green line shows the behaviour of the melting point for most substances; the dotted green line shows the anomalous behavior of water. The red lines show the sublimation temperature and th... | |
earth_science-3/extraction_0.txt | # Shock Melting Curve of Iron: A Consensus on the Temperature at the Earth's Inner Core Boundary ## 1 Introduction Earth's core is composed of an iron alloy with a certain amount of light elements, such as Si, S, O, C, and H (Li & Fei, 2014). The melting temperatures of iron and its alloys at high pressures are critica... | |
earth_science-3/extraction_1.txt | 1. Introduction Earth's core is composed of an iron alloy with a certain amount of light elements, such as Si, S, O, C, and H (Li & Fei, 2014). The melting temperatures of iron and its alloys at high pressures are critical geophysical parameters for understanding the thermal structure, inner core solidification, and en... | |
earth_science-3/extraction_2.txt | Related Perspective Molten iron in Earth-like exoplanet cores By Youjun Zhang, Jung-Fu LinScience**14 Jan 2022** With the discovery of planets outside our Solar System, the search for life on other planetary bodies is one of the grand challenges of our time. This search among the diverse landscape of planets has driven... | |
earth_science-3/extraction_3.txt | ## Outer Core: The outer core, which has been confirmed to be liquid (based on seismic investigations), is 2300 km thick, extending to a radius of ~3,400 km. In this region, the density is estimated to be much higher than the mantle or crust, ranging between 9,900 and 12,200 kg/m3. The outer core is believed to be comp... | |
earth_science-3/extraction_5.txt | **Earth's inner core** is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,230 km (760 mi), which is about 20% of Earth's radius or 70% of the Moon's radius.[\[1\]](https://en.wikipedia.org/wiki/Earth%27s_inner_core?utm_source=chatgpt.com#cite_note-monner2010-1)[\[... | |
magma_chambers/Seismic_tomography4.txt |
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magma_chambers/Seismic_tomography5.txt | Reflection tomography originated with exploration geophysics. It uses an artificial source to resolve small-scale features at crustal depths.[8] Wide-angle tomography is similar, but with a wide source to receiver offset. This allows for the detection of seismic waves refracted from sub-crustal depths and can determine... | |
earth_science-40/extraction_0.txt | Researchers from the U.S. Geological Survey and Oregon State University examined the area beneath Yellowstone Volcanic system finding that although an eruption is unlikely anywhere in the area, changes to the northeast area of the volcanic system will be the key to understanding future eruptions. Scientists at USGS map... | |
earth_science-40/extraction_1.txt | Here, using the Yellowstone plateau as an example, we review current understanding of magma storage regions as relevant to volcanic hazards. We focus on two popular techniques for characterizing magma reservoirs, one geophysical (seismic tomography) and the other petrological (geospeedometry). Magma is a high-temperatu... | |
earth_science-40/extraction_2.txt | In the Southern Volcanic Zone of the Chilean Andes between 34° and 36°S, several large-volume silicic eruptions have occurred during the Quaternary behind the volcanic front. These include the Maipo-Diamante caldera, the Calabozos caldera, the Puelche volcanic field, and the Laguna del Maule (LdM) volcanic field \ _Hil... | |
earth_science-40/extraction_3.txt | ## Introduction In the central Andes between 14°S and 28°S is the Central Volcanic Zone (CVZ), a collection of andesitic to dacitic stratovolcanoes, regionally extensive voluminous crystal-rich dacitic ignimbrites, and minor small-volume monogenetic mafic centers (de Silva and Francis, 1991). Located at the center of t... | |
earth_science-40/extraction_4.txt | The Altiplano of the central Andes is a broad plateau with substantial relief (elevations $3 . 5 { - } 4 . 7 ~ \\mathsf { k m } )$ that overlies a $7 0 – \\mathbf { k m }$ -thick crust (Isacks, 1988). Located in the Altiplano area, Cerro Uturuncu is a stratovolcano within a regional cluster of young calderas and ignimb... | |
earth_science-40/extraction_5.txt | ## Introduction The Altiplano-Puna Magma Body (APMB) resides within the Altiplano-Puna plateau, a region that is characterized by a higher mean elevation[1], [2] than the Altiplano to the north, a thickened crust[3], [4], and a very thin mantle lithosphere[4]. The thin lithosphere beneath the APVC may result from conve... | |
earth_science-40/extraction_6.txt | ## Abstract Magnetotelluric (MT) data were collected at the Laguna del Maule volcanic field (LdMVF), located in central Chile (36°S, 70.5°W), which has been experiencing unprecedented upward ground deformation since 2007. These data were used to create the first detailed three-dimensional electrical resistivity model o... | |
earth_science-40/extraction_7.txt | ## Abstract Supereruptions are the largest explosive volcanic eruptions on Earth. They generate catastrophic, widespread ash-fall blankets and voluminous ignimbrites, with accompanying caldera collapse. However, the mechanisms of generation, storage and evacuation of the parental silicic magma bodies remain controversi... | |
earth_science-40/extraction_8.txt | Physical decoupling of the crystal, melt and volatile phases will also affect their chemical signatures. In this way, different processes are recorded by the non-eruptible mush, the mobile melt, and the magma (which may combine both mobile and nonmobile elements). Segregation of melt from crystal mush explains extensiv... | |
earth_science-40/extraction_9.txt | ### 8\. Applications to volcano monitoring What implications does our new understanding of the depth and form of magma reservoirs have for monitoring (and forecasting) eruptions? The previous sections summarize geophysical and petrological evidence for multiple magma storage areas in the crust, and deep storage regions... | |
earth_science-40/extraction_10.txt | Despite extensive seismic surveys in various volcanic settings across the world, eruptible melt lenses have yet to be unequivocally detected. For example, local earthquake tomography using traveltimes in the Taupo Volcanic Zone, one of the most active rhyolitic systems on Earth with a magma eruption rate of 9.5 × 10−3 ... | |
geomagnetic_pulse/Geomagnetic_jerk5.txt |
From Wikipedia, the free encyclopedia
Sudden change in the Earth's magnetic field
In geophysics, a geomagnetic jerk or secular geomagnetic variation impulse is a relatively sudden change in the second derivative of the Earth's magnetic field with respect to time.[1]
These events were noted by Vincent Courtillot... | |
earth_science-41/extraction_1.txt | ## 1\. Introduction A geomagnetic jerk can be defined as a sudden change (a _V_-shape like change) in the slope of the geomagnetic secular variation, i.e., the first time derivative of the Earth's magnetic field ( Mandea et al., 2010). Geomagnetic jerks were first reported by Courtillot et al. (1978). Various technique... | |
earth_science-41/extraction_2.txt | # Geomagnetic jerks finally reproduced and explained April 22, 2019 Earth The Earth’s magnetic field experiences unpredictable, rapid, and intense anomalies that are known as geomagnetic jerks. The mechanisms behind this phenomenon had remained a mystery until the recent research of a CNRS researcher at l’Institut de p... | |
earth_science-41/extraction_3.txt | 1\. Introduction Typically, global SV varies smoothly over decades. However, sometimes relatively rapid changes occur on the timescale of several months to a year that interrupts the steady progression. These rapid changes in SV are known as geomagnetic jerks (e.g. Courtillot et al., 1978; Brown et al., 2013). They are... | |
earth_science-42/extraction_0.txt | ### Significance Evidence for carbon cycling or biologic activity can be derived from carbon isotopes, because a high 12C/13C ratio is characteristic of biogenic carbon due to the large isotopic fractionation associated with enzymatic carbon fixation. The earliest materials measured for carbon isotopes at 3.8 Ga are is... | |
earth_science-42/extraction_2.txt | The discussion about small size in early metazoans is a topic that is recurrently revisited \e.g. [230– 234\]. The basic idea is that small size might have played a crucial role in their virtual absence in the Precambrian fossil record, favouring a strong taphonomic bias over actual non-existence. Small size could be a... | |
earth_science-42/extraction_3.txt | Of course, preservational biases can have huge impacts on palaeoecological studies (Nanglu and Cullen 2023). However, the exceptional preservation for many fossil localities spanning the ECT means that analytical techniques normally only applicable for extant systems can be used. The preservation of Ediacaran macrofoss... | |
earth_science-42/extraction_4.txt | ## What does the fossil record tell us? Precambrian palaeontologists are at loss to search for animal remains in ancient rocks, but results are somewhat awkward. The findings do not extend the dawn of animal life much further back. Body, trace, and chemical remains of animals are not as ancient as Darwin predicted but ... | |
earth_science-42/extraction_5.txt | ### Abstract Devonian tetrapods (limbed vertebrates), known from an increasingly large number of localities, have been shown to be mainly aquatic with many primitive features. In contrast, the post-Devonian record is marked by an Early Mississippian temporal gap ranging from the earliest Carboniferous (Tournaisian and ... | |
earth_science-42/extraction_6.txt | The origin of tetrapods, understood as an evolutionary and ecological phenomenon, was not a single event but a process that began with the acquisition of incipient terrestrial locomotory competence in the tetrapod stem group and ended with the emergence of the major crown-group clades, amphibians and amniotes. Of parti... | |
earth_science-42/extraction_7.txt | A faunal turnover of tetrapods has long been recognised between the Cisuralian and Guadalupian (early and middle Permian, respectively). The former is characterised by a diverse array of amphibians, pelycosaurian-grade synapsids (particularly carnivorous sphenacodontids and herbivorous edaphosaurids), and captorhinids,... | |
earth_science-42/extraction_8.txt | ### 1\. Introduction Adaptive radiations and mass extinctions have occupied a central position in macro-evolutionary theory as explanations for major shifts in prevailing faunas/floras at particular points in time \ [1, 2\]. Examples of rapid radiations of novel lineages to fill ecospace left vacant by large-scale exti... | |
earth_science-42/extraction_9.txt | # ABSTRACT During the Permian, tetrapods showed a major transition from basal synapsid-dominated faunas in the fi rst half to therapsiddominated faunas in the second. The transition was signifi cant in marking the beginning of richer and more complex communities, a precursor to modern terrestrial ecosystems. This chang... | |
earth_science-42/extraction_10.txt | ## Results and Discussion We identified 57 types of mouthparts and reported their distribution during time (Fig. 1, Supporting Information). Some types concern orders, groups of families, while other are found in single subfamilies. The chosen types are characterized by their high specialization in feeding and biology,... | |
earth_science-42/extraction_11.txt | # Phanerozoic _p_ O2 and the early evolution of terrestrial animals ## Abstract Concurrent gaps in the Late Devonian/Mississippian fossil records of insects and tetrapods (i.e. Romer's Gap) have been attributed to physiological suppression by low atmospheric _p_ O2. Here, updated stable isotope inputs inform a reconstr... | |
earth_science-42/extraction_13.txt | It is commonly inferred from molecular data (calibrated with the fossil record) that the LCA of the chimpanzee/bonobo–human clade existed between 6 and 8 Ma ( Steiper & Young, 2006), although some estimates have put the split considerably later ( Patterson et al. 2006). The recent discoveries of _Sahelanthropus tchaden... | |
earth_science-42/extraction_14.txt | Perhaps not surprisingly, **hominins** (see Glossary) have the starring role in **hominoid** evolution. The uniqueness of the phylogenetic tip (modern humans) makes this inevitable, with a rich history of adaptive changes and the emergence of novel phenotypes and behaviours. By contrast, while African apes have had an ... | |
earth_science-42/extraction_15.txt | The fossil record of humans is notoriously patchy and incomplete. Even so, skeletal remains and artifacts unearthed in Africa in recent decades have done much to illuminate human evolution. But what is the origin of the genus _Homo_? Villmoare _et al._ found a fossil mandible and teeth from the Afar region in Ethiopia.... | |
earth_science-42/extraction_16.txt | ## Abstract The time interval between about three and two million years ago is a critical period in human evolution—this is when the genera _Homo_ and _Paranthropus_ first appear in the fossil record and a possible ancestor of these genera, _Australopithecus afarensis_, disappears. In eastern Africa, attempts to test h... | |
earth_science-42/extraction_18.txt | These paleoecological reconstructions hinge on large, quantitative studies of fossil databases tailored to uncovering specific biotic patterns in Earth’s history. before meaningful and accurate analyses can be performed, such databases must be carefully vetted to accommodate the many forms of common bias that affect an... | |
earth_science-42/extraction_19.txt | ## Discussion ### Understanding the Structure of the Terrestrial Fossil Record How good is the terrestrial fossil record, really? Foote's ( Reference Foote1997) and Tietje and Rodel's (2017) estimates of the completeness of the mammalian and amphibian fossil record, though quite disparate in scope, correspond with our ... | |
earth_science-42/extraction_21.txt | The **Signor–Lipps effect** is a paleontological principle proposed in 1982 by Philip W. Signor") and Jere H. Lipps which states that, since the fossil record of organisms is never complete, neither the first nor the last organism in a given taxon will be recorded as a fossil.[\[1\]](https://en.wikipedia.org/wiki/Signo... | |
symmetric_crater/Impact_crater3.txt |
AfrikaansAlemannischالعربيةAsturianuAzərbaycancaবাংলাBân-lâm-gúБеларускаяБеларуская (тарашкевіца)БългарскиBosanskiBrezhonegCatalàČeštinaDanskDeutschEestiΕλληνικάEspañolEsperantoEuskaraفارسیFrançaisGalego한국어Հայերենहिन्दीHrvatskiBahasa IndonesiaItalianoעבריתქართულიҚазақшаKiswahiliКыргызчаLatinaLatviešuLëtzebuergeschLi... | |
earth_science-43/extraction_0.txt | Why are most craters circular ( even craters found on Earth)? By hurtling objects together at many miles per second in large laboratories, scientists have shown that only the most oblique impacts (less than 10° from the horizon) produce elliptical craters. The kinetic energy of an impactor behaves much like the energy ... | |
earth_science-43/extraction_1.txt | ## Shaping the Planets: Impact Cratering Impact cratering is the excavation of a planet's surface when it is struck by a meteoroid. Impacts are instantaneous events. They leave very characteristic features. **What are craters?** Craters are roughly circular, excavated holes made by impact events. The circular shape is ... | |
earth_science-43/extraction_2.txt | 6.3 Cratering mechanics the impact of an object moving at many kilometers per second with the surface of a planet initiates an orderly sequence of events that eventually produces an impact crater. although this is really a continuous process, it is convenient to break it up into distinct stages that are each dominated ... | |
earth_science-43/extraction_3.txt | The small pond of impact melt and debris on the floor of Hercules E is not circular. What forces teamed up to result in this small triangular crater floor deposit? NAC M170300291R, image width 500 m \[NASA/GSFC/Arizona State University\]. Simple craters on the Moon, roughly ≤15 - 20 km in diameter, are typically bowl-s... | |
aurora_equator/Carrington_Event4.txt |
Associated solar flare[edit]
Just before noon on 1 September 1859, the English amateur astronomers Richard Christopher Carrington and Richard Hodgson independently recorded the earliest observations of a solar flare.[8] Carrington and Hodgson compiled independent reports which were published side by side in Monthly No... |
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