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Julie Brigham-Grette
Julie Brigham-Grette is a glacial geologist and a professor in the Department of Geosciences at the University of Massachusetts Amherst where she co-directs the Joseph Hartshorn Quaternary Laboratory. Her research expertise is in glacial geology and paleoclimatology; she has made important contributions to Arctic marine and terrestrial paleoclimate records of late Cenozoic to recent, the evolution of the Arctic climate, especially in the Beringia/ Bering Strait region, and was a leader of the international Lake El’gygytgyn Drilling Project in northeastern Russia. Early life and education Brigham-Grette received a BA in geology from Albion College (Michigan) in 1976 graduating magna cum laude. While an undergraduate enrolled in a course on Glaciers and the Pleistocene at Albion College, Professor Lawrence D. Taylor inspired her to study glacial geology and paleoclimatology. In 1977, Brigham-Grette began her graduate studies at the Institute of Arctic and Alpine Research (I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Geology
Quaternary geology is the branch of geology that study developments from 2.6 million years ago onwards. In particular, Quaternary geology study the process and deposits that developed during the Quaternary, a period characterized by glacial-interglacial cycles. Quaternary geology has developed over time from being originally a branch of historical geology to becoming a science on its own. Quaternary geochronology Quaternary geological investigations that require the dating of rocks or sediments require a complementary array of methods to determine that age. Although radiometric dating has rapidly gained importance for Quaternary dating there has historically been a reliance on chemical/biological traces, geomorphic, and relative dating (also known as correlative dating). Since Quaternary geology involves studying changes on the earth surface up to the present, Quaternary geologists benefit from the preservation of time-dependent chemical or biological processes. These methods includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baffin Island
Baffin Island (formerly Baffin Land), in the Canadian territory of Nunavut, is the largest island in Canada and the fifth-largest island in the world. Its area is , slightly larger than Spain; its population was 13,039 as of the 2021 Canadian census; and it is located at . It also contains the city of Iqaluit, the capital of Nunavut. Name The Inuktitut name for the island is , which means "very big island" ( "island" + "very big") and in Inuktitut syllabics is written as . This name is used for the administrative region the island is part of ( Qikiqtaaluk Region), as well as in multiple places in Nunavut and the Northwest Territories, such as some smaller islands: Qikiqtaaluk in Baffin Bay and Qikiqtaaluk in Foxe Basin. Norse explorers referred to it as ("stone land"). In 1576, English seaman Martin Frobisher made landfall on the island, naming it "Queen Elizabeth's Foreland" and Frobisher Bay is named after him. The island is named after English explorer Willia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ordini). The term "quaternary" was introduced by Jules Desn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate
A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate group C(=O)(O–)2. The term is also used as a verb, to describe carbonation: the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverageseither by the addition of carbon dioxide gas under pressure or by dissolving carbonate or bicarbonate salts into the water. In geology and mineralogy, the term "carbonate" can refer both to carbonate minerals and carbonate rock (which is made of chiefly carbonate minerals), and both are dominated by the carbonate ion, . Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock. The most common are calcite or calcium carbonate, CaCO3, the chief constituent of limestone (as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid Dating
Amino acid dating is a Dating methodology (archaeology), dating technique used to estimate the age of a specimen in paleobiology, molecular paleontology, archaeology, forensic science, taphonomy, sedimentary geology and other fields. This technique relates changes in amino acid molecules to the time elapsed since they were formed. All biological tissues contain amino acids. All amino acids except glycine (the simplest one) are optical activity, optically active, having a stereocenter at their α-carbon, C atom. This means that the amino acid can have two different configurations, "D" or "L" which are mirror images of each other. With a few important exceptions, living organisms keep all their amino acids in the "L" configuration. When an organism dies, control over the configuration of the amino acids ceases, and the ratio of D to L moves from a value near 0 towards an equilibrium value near 1, a process called racemization. Thus, measuring the ratio of D to L in a sample enabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is provided by tools such as paleomagnetism and stable isotope ratios. By combining multiple geochronological (and biostratigraphic) indicators the precision of the recovered age can be improved. Geochronology is different in application from biostratigraphy, which is the science of assigning sedimentary rocks to a known geological period via describing, cataloging and comparing fossil floral and faunal assemblages. Biostratigraphy does not ''directly'' provide an absolute age determination of a rock, but merely places it within an ''interval'' of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand, however, to the point where they share the same system of naming strata (rock layers) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gifford H
Gifford or Giffords may refer to: People *Gifford (given name) *Gifford (surname) *Gabby Giffords (b. 1970), a former United States politician Places Canada * Gifford Peninsula, on the South Coast of British Columbia * Gifford, British Columbia, a locality in the Matsqui Prairie area of the City of Abbotsford, British Columbia * Gifford Slough, a slough in the Matsqui Prairie area of the City of Abbotsford, British Columbia * Gifford Creek, a creek in the Cariboo region of the British Columbia Interior England * Aveton Gifford, Devon * Bowers Gifford, Essex * Broughton Gifford, Wiltshire * Crowmarsh Gifford, Oxfordshire * Fonthill Gifford, Wiltshire * Stoke Gifford, Gloucestershire Scotland * Gifford, East Lothian * Giffordland, North Ayrshire United States * Gifford Park, a neighborhood of Omaha, Nebraska * Gifford, Florida * Gifford, Idaho * Gifford, Illinois * Gifford, Indiana * Gifford, Iowa * Gifford, New York * Gifford Creek (New York), a creek * Gifford, Pennsylvani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaskan
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states (Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th parallel, wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Level
Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised geodetic datumthat is used, for example, as a chart datum in cartography and marine navigation, or, in aviation, as the standard sea level at which atmospheric pressure is measured to calibrate altitude and, consequently, aircraft flight levels. A common and relatively straightforward mean sea-level standard is instead the midpoint between a mean low and mean high tide at a particular location. Sea levels can be affected by many factors and are known to have varied greatly over geological time scales. Current sea level rise is mainly caused by human-induced climate change. When temperatures rise, mountain glaciers and the polar ice caps melt, increasing the amount of water in water bodies. Because most of human settlement and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
