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Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Younger Dryas
The Younger Dryas (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stage of the Pleistocene epoch (c. 2,580,000 to 11,700 years BP) and it preceded the current, warmer Holocene epoch. The Younger Dryas was the most severe and long lasting of several interruptions to the warming of the Earth's climate, and it was preceded by the Late Glacial Interstadial (c. 14,670 to 12,900 BP). The change was relatively sudden, taking place in decades, and it resulted in a decline of temperatures in Greenland by 4~10 °C (7.2~18 °F), and advances of glaciers and drier conditions over much of the temperate Northern Hemisphere. A number of theories have been put forward about the cause, and the most widely supported by scientists is that the Atlantic meridional overturning circulation, which transports warm water fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene Glacial Retreat
The Holocene glacial retreat is a geographical phenomenon that involved the global retreat of glaciers ( deglaciation) that previously had advanced during the Last Glacial Maximum. Ice sheet retreat initiated ca. 19,000 years ago and accelerated after ca. 15,000 years ago. The Holocene, starting with abrupt warming 11,700 years ago, resulted in rapid melting of the remaining ice sheets of North America and Europe. Geographical alterations Antarctica Radiocarbon dating has been used to date the start of glacial retreat on Alexander island 18,000 years ago. The outermost locations like Marguerite Bay were fully deglaciated 12,000 years ago and the further inland locations continued deglaciating for an additional 3,000 years. The Larsen ice shelf was formed in the early Holocene at a latest estimation of 10,700 years ago. Certain segments of the ice shelf have collapsed as recently as 1995 for Larsen A and a large segment of Larsen B collapsed in 2002. Europe The many valleys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meghalayan
The Meghalayan age is the name given in 2018, by the International Commission on Stratigraphy, to the current age or latest geologic age – or uppermost stage of the Quaternary. It is also the upper, or latest, of three subdivisions of the Holocene epoch or series. This way of breaking down time is based only on geology; for example it's unrelated to the three age system of historical periods into which human development is sometimes divided. The Meghalayan begins 4,200 years BP ( 2251 BCE or 7750 HE), leaving room for the possible introduction of the Anthropocene. Helama & Oinonen (2019) dated the start of the Meghalayan to 2190-1990 BCE. The age began with a 200-year drought that impacted human civilizations in the Eastern Mediterranean, Mesopotamia, the Indus Valley and the Yangtze River Valley. "The fact that the beginning of this age coincides with a cultural shift caused by a global climate event makes it unique," according to Stanley Finney, Secretary General of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flandrian Interglacial
The Flandrian interglacial or stage is the name given by geologists and archaeologists in the British Isles to the first, and so far only, stage of the Holocene epoch (the present geological period), covering the period from around 12,000 years ago, at the end of the last glacial period to the present day. As such, it is in practice identical in span to the Holocene. The Flandrian began as the relatively short-lived Younger Dryas climate downturn came to an end. This formed the last gasp of the Devensian glaciation, the final stage of the Pleistocene epoch. The Flandrian is traditionally seen as the latest warm interglacial in a series that has been occurring throughout the Quaternary geological period. The first part of the Flandrian, known as the Younger Atlantic, was a period of fairly rapid sea level rise, known as the Flandrian transgression. It is associated with the melting of the Fenno-Scandian, Scottish, Laurentide and Cordilleran glaciers. Fjords were formed durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northgrippian
In the geologic time scale, the Northgrippian is the middle one of three ages or stages of the Holocene Epoch or Series. It was officially ratified by the International Commission on Stratigraphy in June 2018 along with the earlier Greenlandian and later Meghalayan ages/stages. The age takes its name from the North Greenland Ice Core Project (NorthGRIP). The age began 8,276 BP (6326 BCE or 3854 HE), near the 8.2-kiloyear event, and goes up to the start of the Meghalayan, which began 4,200 BP (2250 BCE or 7750 HE), near the 4.2-kiloyear event. See also * Geologic time scale * NorthGRIP The drilling site of the North Greenland Ice Core Project (NGRIP or NorthGRIP) is near the center of Greenland (75.1 N, 42.32 W, 2917 m, ice thickness 3085). Drilling began in 1999 and was completed at bedrock in 2003. The cores are cylinder ... * 5th millennium BC References 7th millennium BC *01 Geological epochs * *03 * {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenlandian
In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending 8,276 BP (6237 BCE or 3764 HE), it is the earliest of three sub-divisions of the Holocene. It was officially ratified by the International Commission on Stratigraphy in June 2018 with the later Northgrippian and Meghalayan Ages/Stages. The lower boundary of the Greenlandian Age is the GSSP sample from the North Greenland Ice Core Project in central Greenland (75.1000°N 42.3200°W). The Greenlandian GSSP has been correlated with the end of Younger Dryas The Younger Dryas (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stage ... (from near-glacial to interglacial) and a "shift in deuterium excess values". Referenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interglacial
An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene interglacial began at the end of the Pleistocene, about 11,700 years ago. Pleistocene During the 2.5 million years of the Pleistocene, numerous glacials, or significant advances of continental ice sheets, in North America and Europe, occurred at intervals of approximately 40,000 to 100,000 years. The long glacial periods were separated by more temperate and shorter interglacials. During interglacials, such as the present one, the climate warms and the tundra recedes polewards following the ice sheets. Forests return to areas that once supported tundra vegetation. Interglacials are identified on land or in shallow epicontinental seas by their paleontology. Floral and faunal remains of species pointing to temperate climate and indicating a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation RCYBP stands for the explicit "radio carbon years before present". Usage The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. This usage differs from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Time Scale
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 (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 standardized international units of geologic 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 precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age (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 (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 standardized international units of geologic 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 precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Species
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically modern hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
