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Submerged Continent
A submerged continent or a sunken continent is a region of continental crust, extensive in size but mainly undersea. The terminology is used by some paleogeologists and geographers in reference to some landmasses (none of which are as large as any of the seven generally-recognized continents). The definition of this term is unclear. If continental fragments and microcontinents smaller than , which is approximately one third of the area of mainland Australia, are excluded, then Zealandia (approximately ) would be the only geological feature which is classifiable as a submerged continent. Other notable submerged lands include Beringia, Doggerland, the Kerguelen Plateau, Mauritia, Sahul, and Sunda. Submerged continents have been sought and speculated about in regard to a possible " lost continent" underwater in the Atlantic Ocean. There was also a search in the 1930s for Lemuria Lemuria (), or Limuria, was a continent proposed in 1864 by zoologist Philip Sclater, theorize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doggerland
Doggerland was a large area of land in Northern Europe, now submerged beneath the southern North Sea. This region was repeatedly exposed at various times during the Pleistocene epoch due to the lowering of sea levels during glacial periods. However, the term "Doggerland" is generally specifically used for this region during the Late Pleistocene and Early Holocene. During the early Holocene following the glacial retreat at the end of the Last Glacial Period, the exposed land area of Doggerland stretched across the region between what is now the east coast of Great Britain, the Netherlands, north-west Germany, and the Danish peninsula of Jutland. Between 10,000 and 7,000 years ago, Doggerland was inundated by rising sea levels, disintegrating initially into a series of low-lying islands before submerging completely. The impact of the tsunami generated by the Storegga underwater landslide 8,200 years ago on Doggerland is controversial. The flooded land is known as the Dogger Lit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemuria (continent)
Lemuria (), or Limuria, was a continent proposed in 1864 by zoologist Philip Sclater, theorized to have sunk beneath the Indian Ocean, later appropriated by occultists in supposed accounts of human origins. The theory was discredited with the discovery of plate tectonics and continental drift in the 20th century. The hypothesis was proposed as an explanation for the presence of lemur fossils on Madagascar and the Indian subcontinent but not in continental Africa or the Middle East. Biologist Ernst Haeckel's suggestion in 1870 that Lemuria could be the ancestral home of humans caused the hypothesis to move beyond the scope of geology and zoogeography, ensuring its popularity outside of the framework of the scientific community. Occultist and founder of theosophy Helena Blavatsky, during the latter part of the 19th century, placed Lemuria in the system of her mystical-religious doctrine, claiming that this continent was the homeland of the human ancestors, whom she called Lemurians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas (North America and South America) from the Old World of Afro-Eurasia (Africa, Asia, and Europe). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse colonization of North America, Norse were the first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus's expedition ushered in an Age of Discovery, age of exploration and colonization of the Americas by European powers, most notably Portuguese Empire, Portugal, Spanish Empire, Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Lost Lands
Lost lands are islands or continents believed by some to have existed during prehistory, but to have since disappeared as a result of catastrophic geological phenomena. Legends of lost lands often originated as scholarly or scientific theories, only to be picked up by writers and individuals outside the academy. Occult and New Age writers have made use of lost lands, as have subaltern peoples. Phantom islands, as opposed to lost lands, are land masses formerly believed by cartographers to exist in the ''current'' historical age, but to have been discredited as a result of expanding geographic knowledge. The classification of lost lands as continents, islands, or other regions is in some cases subjective; for example, Atlantis is variously described as either a "lost island" or a "lost continent". Lost land theories may originate in mythology or philosophy, or in scholarly or scientific theories, such as catastrophic theories of geology. With the development of plate tecton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunda Shelf
Geology, Geologically, the Sunda Shelf () is a south-eastern extension of the continental shelf of Mainland Southeast Asia. Major landmasses on the shelf include the Indonesia, Indonesian islands of Bali, Borneo, Java, Madura Island, Madura, and Sumatra, as well as their surrounding smaller islands. It covers an area of approximately 1.85 million km2.va Bemmelen, R.W. (1949). ''The Geology of Indonesia.'' Vol. IA'': General Geology of Indonesia and Adjacent Archipelagoes.'' Matinus Nithoff, The Hague, 723 pp. Sea depths over the shelf rarely exceed 50 metres and extensive areas are less than 20 metres resulting in strong bottom friction and strong tidal friction. Steep undersea gradients separate the Sunda Shelf from the Philippines, Sulawesi, and the Lesser Sunda Islands (not including Bali). Definition Biogeography, Biogeographically, Sundaland is a term for the region of Southeast Asia, Southeastern Asia which encompasses these areas of the Asian continental shelf that were L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sahul Shelf
Geology, Geologically, the Sahul Shelf () is a part of the continental shelf of the Australia (continent), Australian continent, lying off the northwest coast of mainland Australia. Etymology The name "Sahull" or "Sahoel" appeared on 17th century Dutch maps applied to a submerged shoal, sandbank between Australia and Timor. On his 1803 map, Matthew Flinders noted the "Great Sahul Shoal" where Malay race, Indonesians came from Makassar to fish for ''trepang'' (sea cucumber). The name Sahul Shelf () was coined in 1919 by Gustaaf Adolf Frederik Molengraaff, G.A.F. Molengraaff, an authority on the geology of the then Dutch East Indies. Geography The Sahul Shelf proper stretches northwest from Australia much of the way under the Timor Sea towards Timor, ending where the seabed begins descending into the Timor Trough. To the northeast, the Sahul Shelf merges into the Arafura Shelf, which runs from the northern coast of Australia under the Arafura Sea north to New Guinea. The Aru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauritia (microcontinent)
Mauritia was a Precambrian microcontinent that was situated between India and Madagascar until their separation about 70 million years ago. Being initially attached to the Indian continent, Mauritia separated from it about 60 million years ago and further fragmented into a ribbon-like structure as the mid-ocean ridge jumped several times. The jumps of the mid-ocean ridge are thought to have been caused of its interaction with the Réunion hotspot as it passed under the West margin of the Indian continent and then under Mauritia. As of today, the fragments of Mauritia include the Laccadives–Maldives–Chagos Ridge, Nazareth Bank, the Saya de Malha Bank, and Hawkins Bank, as well as the islands of Réunion and Mauritius, where the continual crust is buried under basaltic lavas of the Réunion hotspot. Evidence for Mauritia's existence consists of detrital zircon found in rock (6-million-year-old trachyte) on Mauritius. Analyses of the zircon crystals produced dates between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerguelen Plateau
The Kerguelen Plateau (, ), also known as the Kerguelen–Heard Plateau, is an oceanic plateau and large igneous province (LIP) located on the Antarctic Plate, in the southern Indian Ocean. It is about to the southwest of Australia and is nearly three times the size of California. The plateau extends for more than in a northwest–southeast direction and lies in deep water. The plateau was produced by the Kerguelen hotspot, starting with or following the breakup of Gondwana about 130 million years ago. A small portion of the plateau breaks sea level, forming the Kerguelen Islands (a overseas territory (France), French overseas territory) plus the Heard Island and McDonald Islands, Heard and McDonald Islands (an states and territories of Australia, Australian external territory). Intermittent volcanism continues on the Heard and McDonald Islands. Geographical extent Symmetrically across the Indian Ocean ridge and due west of Australia is the Broken Ridge underwater volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beringia
Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 70th parallel north, 72° north latitude in the Chukchi Sea; and on the south by the tip of the Kamchatka Peninsula. It includes the Chukchi Sea, the Bering Sea, the Bering Strait, the Chukchi Peninsula, Chukchi and Kamchatka peninsulas in Russia as well as Alaska in the United States and Yukon in Canada. The area includes land lying on the North American Plate and Siberian land east of the Chersky Range. At various times, it formed a land bridge referred to as the Bering land bridge, that was up to wide at its greatest extent and which covered an area as large as British Columbia and Alberta together, totaling about , allowing biological dispersal to occur between Asia and North America. Today, the only land that is visible from the central part of the Bering land bridge are the Diomede Islands, the Pribilof Isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landmass
A landmass, or land mass, is a large region or area of land that is in one piece and not noticeably broken up by oceans. The term is often used to refer to lands surrounded by an ocean or sea, such as a continent or a large island. In the field of geology, a landmass is a defined section of continental crust extending above sea level. Continents are often thought of as distinct landmasses and may include any islands that are part of the associated continental shelf. When multiple continents form a single contiguous land connection, the connected continents may be viewed as a single landmass. Earth's largest landmasses are (starting with largest): # Afro-Eurasia (main landmass of the geoscheme region of the same name and its continental parts Africa and Eurasia - or Europe and Asia; the center of Earth's land hemisphere, comprising more than half of Earth's landmass) # Americas (main landmass of the geo-region of the same name and its continental parts North America, North and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zealandia
Zealandia (pronounced ), also known as (Māori language, Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged continent, submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83–79 million years ago. It has been described variously as a submerged continent, continental fragment, and microcontinent. The name and concept for Zealandia was proposed by Bruce P. Luyendyk, Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is over a billion years old, about twice as old as geologists previously thought. By approximately 23 million years ago, the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia. Mapping of Zealandia concluded in 2023. With a total area of approximately , Zealandia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
