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Land Bridges Of Japan
Due to changes in sea level, Japan has at various times been connected to the continent by , with continental Russia to the north via the Sōya Strait, Sakhalin, and the Mamiya Strait, and with the Korean Peninsula to the southwest, via the Tsushima Strait and Korea Strait. Land bridges also connected the Japanese Islands with each other. These land bridges enabled the migration of terrestrial fauna from the continent and their dispersal within Japan. Geological background Around 25 million years ago, the Sea of Japan began to open, separating Japan from the continent and giving rise to the Japanese island arc system of today. The Sea of Japan as a back-arc basin was open both to the northeast and to the southwest by 14 Ma, while marine transgression further contributed to the isolation and insulation of Japan. Due to the level of tectonic activity in the area and significant subsidence of the Japanese Islands since the Miocene, exact quantification of historic sea level chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Past Sea Level
Global or eustatic sea level has fluctuated significantly over Earth's history. The main factors affecting sea level are the amount and volume of available water and the shape and volume of the ocean basins. The primary influences on water volume are the temperature of the seawater, which affects density, and the amounts of water retained in other reservoirs like rivers, aquifers, lakes, glaciers, polar ice caps and sea ice. Over geological timescales, changes in the shape of the oceanic basins and in land/sea distribution affect sea level. In addition to eustatic changes, local changes in sea level are caused by tectonic uplift and subsidence. Over geologic time sea level has fluctuated by more than 300 metres, possibly more than 400 metres. The main reasons for sea level fluctuations in the last 15 million years are the Antarctic ice sheet and Antarctic post-glacial rebound during warm periods. The current sea level is about 130 metres higher than the historical minimum. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary International
''Quaternary International'' is a peer-reviewed scientific journal on quaternary science published by Elsevier on behalf of the International Union for Quaternary Research. The journal was established in 1989 and covers full spectrum of the physical and natural sciences that are commonly employed in solving problems related to the quaternary period. The editor-in-chief is Min-Te Chen (National Taiwan Ocean University). According to the 2017 ''Journal Citation Reports'', the journal has a 2016 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 2.199. References External links * Quaternary science journals English-language journals Elsevier academic journals Publications established in 1989 Journals published between 27 and 51 times per year Academic jo ... [...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] |
Early Holocene
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] |
Lesser Kuril Chain
The Lesser Kuril Chain (russian: Малая Курильская гряда, ja, しょうクリルれっとう or 小千島列島), is an island chain in the northwestern Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti .... The islands are administered as part of Yuzhno-Kurilsky District of Sakhalin Oblast, Russia, and many sources consider the chain to be geographically part of the Kuril Islands. However, the Japanese government Kuril Islands dispute, claims that these islands are not part of the Kuril Islands and are instead minor islands of Hokkaido Prefecture. The Lesser Kuril Chain lies northeast of the Nemuro Peninsula in Hokkaido, near the southwestern end of the Greater Kuril Chain, from which it is separated by the South Kuril Strait. It consists of Shikotan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kunashir
, other_names = kz, Kün Ashyr; ja, 国後島 , location = Sea of Okhotsk , locator_map = File:Kurily Kunashir.svg , coordinates = , archipelago = Kuril Islands , total_islands = , major_islands = , area = , length = , width = from to , coastline = , highest_mount = Chacha , elevation = , country = , country_admin_divisions_title_1 = Federal subject , country_admin_divisions_1 = Sakhalin Oblast , country_admin_divisions_title_2 = District , country_admin_divisions_2 = Yuzhno-Kurilsky , country_largest_city = , country_largest_city_population = , country_leader_title = , country_leader_name = , population = approx. 7000 , population_as_of = 2007 , density = , ethnic_groups = , additional_info = , country_claim = , country_claim_divisions_title_1 = Prefecture , country_claim_divisions_1 = Hokkaido , country_claim_divisions_titl ... [...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 Desnoye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamchatka Peninsula
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific coast of the peninsula runs the Kuril–Kamchatka Trench. The Kamchatka Peninsula, the Commander Islands, and the Karaginsky Island, constitute the Kamchatka Krai of the Russia, Russian Federation. The vast majority of the 322,079 inhabitants are ethnic Russians, although about 13,000 are Koryaks (2014). More than half of the population lives in Petropavlovsk-Kamchatsky (179,526 in 2010) and nearby Yelizovo (38,980). The Kamchatka peninsula contains the volcanoes of Kamchatka, a World Heritage Site, UNESCO World Heritage Site. Geography Politically, the peninsula forms part of Kamchatka Krai. The southern tip is called Cape Lopatka. (Lopatka is Russian for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proboscidea
The Proboscidea (; , ) are a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. From the mid-Miocene onwards, most proboscideans were very large. The largest land mammal of all time may have been a proboscidean; ''Palaeoloxodon namadicus'' was up to at the shoulder and may have weighed up to , almost double the weight of some sauropods like ''Diplodocus carnegii''. The largest extant proboscidean is the African bush elephant, with a record of size of at the shoulder and . In addition to their enormous size, later proboscideans are distinguished by tusks and long, muscular trunks, which were less developed or absent in early proboscideans. Three species of elephant are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. Elephantidae is the only surviving family of the or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Period
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago. The Holocene is the current interglacial. A time with no glaciers on Earth is considered a greenhouse climate state. Quaternary Period Within the Quaternary, which started about 2.6 million years before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone. Penultimate Glacial Period The Penultimate Glacial Period (PGP) is the glacial period that occurred before the Last Glacial Period. It began about 194,000 years ago and ended 135,000 years ago, with the beginning of the Eemian interglacial. Last Glacial Period The last glacial period was the most recent glacial period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shikama Tokio
(1912–1978) was a Japanese vertebrate palaeontologist. Considered the leading Japanese figure in the field in the immediate pre- and post-war years, species he described include Yabe's giant deer ('' Sinomegaceros yabei''). References External links Shikama Tokio (Japan Paleobiology Database) {{Authority control Japanese paleontologists 1912 births 1978 deaths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
