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Deep-sea wood is the term for wood which sinks to the ocean floor. These wood-falls develop deep sea ecosystems. Deep-sea wood supports unique forms of deep sea community life including chemo-synthetic bacteria. Sources of carbon for these deep sea ecosystems are not limited to sunken wood, but also include kelp and the remains of whales. Much ...
The wood used would found the high-seat pillars of the new hall. [ 2 ] Driftwood carried by Arctic rivers was the main, or sometimes only, source of wood for some Inuit and other Arctic populations living north of the tree line until they came into regular contact with European traders.
Graphical geometry of a propagating rift. Red arrow indicates spreading direction. A propagating rift is a seafloor feature associated with spreading centers at mid-ocean ridges and back-arc basins. [1] They are more commonly observed on faster rate spreading centers (50 mm/year or more). [2]
The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges , where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates .
Earlier theories by Alfred Wegener and Alexander du Toit of continental drift postulated that continents in motion "plowed" through the fixed and immovable seafloor. The idea that the seafloor itself moves and also carries the continents with it as it spreads from a central rift axis was proposed by Harold Hammond Hess from Princeton University and Robert Dietz of the U.S. Naval Electronics ...
The oceanic crust displays a pattern of magnetic lines, parallel to the ocean ridges, frozen in the basalt. A symmetrical pattern of positive and negative magnetic lines emanates from the mid-ocean ridge. [24] New rock is formed by magma at the mid-ocean ridges, and the ocean floor spreads out from this point.
Map of the Great Rift Valley. The Great Rift Valley (Swahili: Bonde la ufa) is a series of contiguous geographic depressions, approximately 6,000 or 7,000 kilometres (4,300 mi) in total length, the definition varying between sources, that runs from the southern Turkish Hatay Province in Asia, through the Red Sea, to Mozambique in Southeast Africa.
Lake Superior in North America, the largest freshwater lake by area, lies in the ancient and dormant Midcontinent Rift. The largest subglacial lake, Lake Vostok, may also lie in an ancient rift valley. [5] Lake Nipissing and Lake Timiskaming in Ontario and Quebec, Canada lie inside a rift valley called the Ottawa-Bonnechere Graben. [6]