|
Late Lutetian Thermal Maximum
The Late Lutetian Thermal Maximum (LLTM), also known as the C19r Event, was a hyperthermal event that occurred during the Lutetian epoch. Timing The LLTM occurred about 41.52 Ma, amidst a broader cooling trend known as the Middle-Late Eocene Cooling (MLEC), and lasted for about 30 kyr. It is believed to have been a globally synchronous event. Causes The LLTM coincided with exceptionally high insolation of the Northern Hemisphere caused by the coincidence of a precession minimum modulated by high eccentricity and an obliquity maximum, which also cooccurred with maxima in the 2.4 Myr eccentricity cycle and the 1.2 Myr obliquity cycle. Effects The high solar irradiance experienced by the Earth during the LLTM caused an acceleration of the water cycle, increasing the rate of runoff and input of terrestrial sediment into the ocean. This resulted in the freshening and eutrophication Eutrophication is a general term describing a process in which nutrients accumulate in a bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperthermal Event
A hyperthermal event corresponds to a sudden warming of the planet on a geologic time scale. The consequences of this type of event are the subject of numerous studies because they can constitute an analogue of current global warming. Hyperthermal events The first event of this type was described in 1991 from a sediment core extracted from a drilling of the Ocean Drilling Program (ODP) carried out in Antarctica in the Weddell Sea. This event occurs at the boundary of the Paleocene and Eocene epochs approximately 56 million years ago. It is now called the Paleocene-Eocene Thermal Maximum (PETM). During this event, the temperature of the oceans increased by more than 5 °C in less than 10,000 years. Since this discovery, several other hyperthermal events have been identified in this lower part of the Paleogene geological period: * the Dan-C2 event at the beginning of the Danian stage of the Paleocene, about 65.2 million years ago, quite the basis of the Cenozoic era; * the D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lutetian
The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene Subepoch. Stratigraphic definition The Lutetian was named after Lutetia, the Latin language, Latin name for the city of Paris. The Lutetian Stage was introduced in scientific literature by French geologist Albert de Lapparent in 1883 and revised by A. Blondeau in 1981. The base of the Lutetian Stage is at the first appearance of the nanofossil ''Blackites inflatus'', according to an official reference profile (GSSP) established in 2011. Of two candidates located in Spain, the Gorrondatxe section was chosen.See thwebsite of Eustoquio Molinafor these candidates. The top of the Lutetian (the base of the Bartonian) is at the first appearance of calcareous nannofossils, calcareous nanoplankton s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (geology)
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardised international units of geological time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth-Science Reviews
''Earth-Science Reviews'' is a monthly peer-reviewed scientific journal published by Elsevier. It covers all aspects of Earth sciences. The editors-in-chief for this journal are A. Chin, C. Doglioni, J.L. Florsheim, M.F.J. Flower, G.R. Foulger, A. Gómez-Tuena, S. Khan, S. Marriott, A.D. Miall, G.F. Panza, J.A. Sanchez-Cabeza, M. Strecker, E.S. Takle, M. Widdowson, and P.B. Wignall. Abstracting and indexing This journal is abstracted and indexed by: According to the ''Journal Citation Reports'', the journal has a 2012 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 7.339. References External links {{Authority control Earth and atmospheric sciences journals Elsevier academic journals English-language journals Monthly journals Academic journals esta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Irradiance
Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m2) in SI units. Solar irradiance is often integrated over a given time period in order to report the radiant energy emitted into the surrounding environment (joule per square metre, J/m2) during that time period. This integrated solar irradiance is called solar irradiation, solar radiation, solar exposure, solar insolation, or insolation. Irradiance may be measured in space or at the Earth's surface after atmospheric absorption and scattering. Irradiance in space is a function of distance from the Sun, the solar cycle, and cross-cycle changes.Michael Boxwell, ''Solar Electricity Handbook: A Simple, Practical Guide to Solar Energy'' (2012), pp. 41–42. Irradiance on the Earth's surface additionally depends on the tilt of the measuri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar System as Earth's North Pole. Due to Earth's axial tilt of 23.439281°, there is a seasonal variation in the lengths of the day and night. There is also a seasonal variation in temperatures, which lags the variation in day and night. Conventionally, winter in the Northern Hemisphere is taken as the period from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer is taken as the period from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the Year#Astronomical years, astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geochemistry, Geophysics, Geosystems
''Geochemistry, Geophysics, Geosystems'' is a peer-reviewed open-access scientific journal covering research in Earth and planetary processes with a focus on understanding the Earth as a system. The journal is published by Wiley on behalf of the American Geophysical Union. As of May 2022 the editor-in-chief is Claudio Faccenna (Roma Tre University and University of Texas at Austin). Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 4.480. References External links *{{Official website, https://agupubs.onlinelibrary.wiley.com/journal/15252027 English-language journals Creative Commons Attribution-licensed journals Earth an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrological Cycle
The water cycle (or hydrologic cycle or hydrological cycle) is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth across different reservoirs. The mass of water on Earth remains fairly constant over time. However, the partitioning of the water into the major reservoirs of ice, fresh water, salt water and atmospheric water is variable and depends on climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere due to a variety of physical and chemical processes. The processes that drive these movements, or fluxes, are evaporation, transpiration, condensation, precipitation, sublimation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different phases: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. The water cycle is driven by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runoff (hydrology)
Runoff is the flow of water across the earth, and is a major component in the hydrological cycle. Runoff that flows over land before reaching a watercourse is referred to as ''surface runoff'' or ''overland flow''. Once in a watercourse, runoff is referred to as '' streamflow'', ''channel runoff'', or ''river runoff''. ''Urban runoff'' is surface runoff created by urbanization Urbanization (or urbanisation in British English) is the population shift from Rural area, rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. .... Background Surface runoff Urban runoff Channel runoff Model Curve number References {{hydrology-stub Hydrology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophication
Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the surface of a river, lake, etc., often because chemicals that are used to help crops grow have been carried there by rain. Eutrophication may occur naturally or as a result of human actions. Manmade, or cultural, eutrophication occurs when sewage, Industrial wastewater treatment, industrial wastewater, fertilizer runoff, and other nutrient sources are released into the environment. Such nutrient pollution usually causes algal blooms and bacterial growth, resulting in the depletion of dissolved oxygen in water and causing substantial environmental degradation. Many policies have been introduced to combat eutrophication, including the United Nations Development Program (UNDP)'s sustainability development goals. Approaches for prevention and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous Nannofossils
Calcareous nannofossils are a class of tiny (less than 30 microns in diameter) microfossils that are similar to coccoliths deposited by the modern-day coccolithophores. The nannofossils are a convenient source of geochronological data due to the abundance and rapid evolution of the single-cell organisms forming them (nannoplankton) and ease of handling of the sediment samples. The practical applications of calcareous nannofossils in the areas of biostratigraphy and paleoecology became clear once the deepwater drilling took off in 1968 with the Deep Sea Drilling Project, and they have been extensively studied ever since. Nannofossils provide one of the most important paleontological records with the contiguous length of 220 million years. History of research Christian Gottfried Ehrenberg, while examining the chalk from Ruegen, recorded in 1836 an observation of what was later termed " coccolith" and had pictured the coccoliths and Discoasters in his ''Mikrogeologie' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeogeography, Palaeoclimatology, Palaeoecology
''Palaeogeography, Palaeoclimatology, Palaeoecology'' ("''Palaeo3''") is a peer-reviewed scientific journal publishing multidisciplinary studies and comprehensive reviews in the field of palaeoenvironmental geology. The journal is edited by Howard Falcon-Lang, Shuzhong Shen, Alex Dickson, Mary Elliot, Meixun Zhao, Lucia Angiolini. It was established in 1965 and is currently published by Elsevier. Indexing and abstracting ''Palaeogeography, Palaeoclimatology, Palaeoecology'' is indexed and abstracted in the following databases: According to the ''Journal Citation Reports'', ''Advance in Space Research'' has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 3.318. References External links * Elsevier academic journals English-language journals Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
