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Topic Review
Carcharodontosaurus
Carcharodontosaurus (/ˌkɑːrkəroʊˌdɒntoʊˈsɔːrəs/; lit. sharp-toothed lizard) is a genus of large carcharodontosaurid theropod dinosaur that existed during the Cenomanian age of the Late Cretaceous in Northern Africa. The genus Carcharodontosaurus is named after the shark genus Carcharodon, itself composed of the Greek karchar[os] (κάρχαρος, meaning "jagged" or "sharp") and odōn (ὀδών, "teeth"), and the suffix -saurus ("lizard"). It is currently known to have two species: C. saharicus and C. iguidensis.
  • 3.2K
  • 09 Nov 2022
Topic Review
Climate Change and Indigenous Peoples
Climate change disproportionately impacts indigenous people around the world, especially in terms of their health, environments, and communities. Indigenous people found in Africa, the Arctic, Asia, Australia, the Caribbean, Latin America, North America and the Pacific have strategies and traditional knowledge to adapt to climate change. These knowledge systems can be beneficial for their own adaptation to climate change as well as applicable to non-indigenous people.   The majority of the world’s biological, ecological, and cultural diversity is located within Indigenous territories. There are over 370 million indigenous peoples found across 90+ countries. Approximately 22% of the planet's land is comprised of indigenous territories, varying slightly depending on how indigeneity and land usage is determined. Indigenous people have the important role of the main knowledge keepers within their communities, including knowledge relating to the maintenance of social-ecological systems. The United Nations Declaration on the Rights of Indigenous People recognizes that Indigenous people have specific knowledge, traditional practices, and cultural customs that can contribute to the proper and sustainable management of ecological resources. Indigenous Peoples have a myriad of experiences with the effects of climate change because of the varying geographical areas they inhabit across the globe and because of the differences in cultures and livelihoods. Indigenous Peoples have a wide variety of experiences that Western science is beginning to include in its research of climate change and its potential solutions. The concepts of ancestral knowledge and traditional practices are increasingly respected and considered in Western scientific research.
  • 530
  • 09 Nov 2022
Topic Review
Daisyworld
Daisyworld, a computer simulation, is a hypothetical world orbiting a star whose radiant energy is slowly increasing or decreasing. It is meant to mimic important elements of the Earth-Sun system, and was introduced by James Lovelock and Andrew Watson in a paper published in 1983 to illustrate the plausibility of the Gaia hypothesis. In the original 1983 version, Daisyworld is seeded with two varieties of daisy as its only life forms: black daisies and white daisies. White petaled daisies reflect light, while black petaled daisies absorb light. The simulation tracks the two daisy populations and the surface temperature of Daisyworld as the sun's rays grow more powerful. The surface temperature of Daisyworld remains almost constant over a broad range of solar output.
  • 306
  • 09 Nov 2022
Topic Review
Submarine Canyon
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from canyon floor to canyon rim, as with the Great Bahama Canyon. Just as above-sea-level canyons serve as channels for the flow of water across land, submarine canyons serve as channels for the flow of turbidity currents across the seafloor. Turbidity currents are flows of dense, sediment laden waters that are supplied by rivers, or generated on the seabed by storms, submarine landslides, earthquakes, and other soil disturbances. Turbidity currents travel down slope at great speed (as much as 70 km/h), eroding the continental slope and finally depositing sediment onto the abyssal plain, where the particles settle out. About 3% of submarine canyons include shelf valleys that have cut transversely across continental shelves, and which begin with their upstream ends in alignment with and sometimes within the mouths of large rivers, such as the Congo River and the Hudson Canyon. About 28.5% of submarine canyons cut back into the edge of the continental shelf, whereas the majority (about 68.5%) of submarine canyons have not managed at all to cut significantly across their continental shelves, having their upstream beginnings or "heads" on the continental slope, below the edge of continental shelves. The formation of submarine canyons is believed to occur as the result of at least two main process: 1) erosion by turbidity current erosion; and 2) slumping and mass wasting of the continental slope. While at first glance, the erosion patterns of submarine canyons may appear to mimic those of river-canyons on land, due to the markedly different erosion processes that have been found to take place underwater at the soil/ water interface, several notably different erosion patterns have been observed in the formation of typical submarine canyons. Many canyons have been found at depths greater than 2 km below sea level. Some may extend seawards across continental shelves for hundreds of kilometres before reaching the abyssal plain. Ancient examples have been found in rocks dating back to the Neoproterozoic. Turbidites are deposited at the downstream mouths or ends of canyons, building an abyssal fan.
  • 1.4K
  • 09 Nov 2022
Topic Review
New Guinea Highlands
The New Guinea Highlands, also known as the Central Range or Central Cordillera, is a long chain of mountain ranges on the island of New Guinea, including the island's tallest peak, Puncak Jaya 16,024 ft (4,884 m), the highest mountain in Oceania. The range is home to many intermountain river valleys, many of which support thriving agricultural communities. The highlands run generally east-west the length of the island, which is divided politically between Indonesia in the west and Papua New Guinea in the east.
  • 2.1K
  • 09 Nov 2022
Topic Review
McClintock Arctic Expedition
The McClintock Arctic Expedition of 1857 was a British effort to locate the last remains of the lost Franklin Arctic Expedition. Led by captain Francis Leopold McClintock aboard the steam yacht Fox, the expedition spent two years in the region and ultimately returned with the only written message from the doomed expedition. McClintock and crew were awarded the Arctic medal in recognition of their achievements.
  • 362
  • 09 Nov 2022
Topic Review
Massetognathus
Massetognathus (/ˌmæsɪˈtɒɡnəθəs/ MASS-ə-TOG-nə-thəss; Greek for "chewing muscle jaw") is an extinct genus of plant-eating traversodontid cynodonts. They lived during the Triassic Period about 235 million years ago, and are known from the Chañares Formation in Argentina and the Santa Maria Formation in Brazil.
  • 310
  • 09 Nov 2022
Topic Review
Homogenization (Climate)
Homogenization in climate research means the removal of non-climatic changes. Next to changes in the climate itself, raw climate records also contain non-climatic jumps and changes, for example due to relocations or changes in instrumentation. The most used principle to remove these inhomogeneities is the relative homogenization approach in which a candidate station is compared to a reference time series based on one or more neighboring stations. The candidate and reference station(s) experience about the same climate, non-climatic changes that happen only in one station can thus be identified and removed.
  • 274
  • 09 Nov 2022
Topic Review
Outline of Geophysics
The following outline is provided as an overview of and topical guide to geophysics: Geophysics – the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations have a broader definition that includes the hydrological cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets.
  • 772
  • 09 Nov 2022
Topic Review
Bush Encroachment
Bush encroachment (also shrub encroachment, woody encroachment, bush thickening, woody plant proliferation) is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause biome shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Bush encroachment is often considered an ecological regime shift and can be a symptom of land degradation. Its causes include land use intensification, such as high grazing pressure and the suppression of wildfires. Climate change is found to be an accelerating factor for woody encroachment. The impact of bush encroachment is highly context specific. It is often found to have severe negative consequences on key ecosystem services, especially biodiversity, animal habitat, land productivity and groundwater recharge. Across rangelands, woody encroachment has led to significant declines of productivity, threatening the livelihoods of affected land users. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally. Various countries actively counter woody encroachment, through adapted grassland management practices and targeted bush thinning. In some cases, areas affected by woody encroachment are classified as carbon sinks and form part of national greenhouse gas inventories. However, carbon sequestration effects of woody encroachment are highly context specific and still insufficiently researched.
  • 4.4K
  • 08 Nov 2022
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