auto-update week 48

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Yo Robot 2022-12-01 22:08:08 +00:00
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}
},
"Major ocean currents": {
"text": "<p>The cold, clockwise-flowing Antarctic Circumpolar Current (West Wind Drift; 21,000 km long) moves perpetually eastward around the continent and is the world's largest and strongest ocean current, transporting 130 million cubic meters of water per second - 100 times the flow of all the world's rivers; it is also the only current that flows all the way around the planet and connects the Atlantic, Pacific, and Indian Oceans; the cold Antarctic Coastal Current (East Wind Drift) is the southernmost current in the world, flowing westward and parallel to the Antarctic coastline</p>"
"text": "<p>the cold, clockwise-flowing Antarctic Circumpolar Current (West Wind Drift; 21,000 km long) moves perpetually eastward around the continent and is the world's largest and strongest ocean current, transporting 130 million cubic meters of water per second - 100 times the flow of all the world's rivers; it is also the only current that flows all the way around the planet and connects the Atlantic, Pacific, and Indian Oceans; the cold Antarctic Coastal Current (East Wind Drift) is the southernmost current in the world, flowing westward and parallel to the Antarctic coastline</p>"
},
"Bathymetry": {
"continental shelf": {
"text": "The <em>continental shelf </em>(see Figure 1), a rather flat area of the sea floor adjacent to the coast that gradually slopes down from the shore to water depths of about 200 m (660 ft). Dimensions can vary: they may be narrow or nearly nonexistent in some places or extend for hundreds of miles in others. The waters along the continental shelf are usually productive in both plant and animal life, both from sunlight and nutrients from ocean upwelling and terrestrial runoff. Compared to the <em>continental shelf</em> found in other oceans, in Antarctica the continental shelf is narrower and much deeper. In addition, the <em>continental shelf</em> has been deeply scoured by glacial action. The following are examples of features found on the <em>continental shelf</em> of the Southern Ocean (see Figure 2).<br>Astrid Ridge (see also Figure 4)<br>Belgrano Bank<br>Gunnerus Ridge (see also Figure 4)<br>Hayes Bank<br>Iselin Bank"
},
"continental slope": {
"text": "The <em>continental slope</em> (see Figure 1) is where the ocean bottom drops off more rapidly until it meets the deep-sea floor (abyssal plain) at about 3,200 m (10,500 ft) water depth. The deep waters of the continental slope are characterized by cold temperatures, low light conditions, and very high pressures. Sunlight does not penetrate to these depths, having been absorbed or reflected in the water above. The <em>continental slope</em> can be indented by submarine canyons, often associated with the outflow of major rivers. In the case of Antarctica, the <em>continental slope</em> has been scoured by glacial action cutting troughs and canyons down the slope. Another feature of the continental slope are alluvial fans or cones of sediments carried downstream to the ocean by major rivers and deposited down the slope. The following are examples of features found on the <em>continental slope</em> of the Southern Ocean (see Figure 2).<br>Amery Basin (see also Figure 4)<br>Filchner Trough<br>Hillary Canyon<br>Pobeda Canyon (Figure 3)"
},
"abyssal plains": {
"text": "The <em>abyssal plains </em>(see Figure 1), at depths of over 3,000 m (10,000 ft) and covering 70% of the ocean floor, are the largest habitat on earth. Sunlight does not penetrate to the sea floor, making these deep, dark ecosystems less productive than those along the continental shelf. Despite their name, these “plains” are not uniformly flat; they are interrupted by features like hills, valleys, and seamounts. The following are examples of features found on the <em>abyssal plains</em> of the Southern Ocean (see Figures 2, 3, and 4).<br>Amundsen (Abyssal) Plain<br>Enderby (Abyssal) Plain<br>South Indian/Australian-Antarctic Basin<br>Southeast Pacific/Bellinghausen Basin<br>Weddell (Abyssal) Plain"
},
"mid-ocean ridge": {
"text": "The <em>mid-ocean ridge </em>(see Figure 1), rising up from the abyssal plain, is an underwater mountain range, over 64,000 km (40,000 mi) long, rising to an average depth of 2,400 m (8,000 ft). <em>Mid-ocean ridges</em> form at divergent plate boundaries where two tectonic plates are moving apart and new crust is created by magma pushing up from the mantle. Tracing their way around the global ocean, this system of underwater volcanoes forms the longest mountain range on Earth. Fracture Zones are linear transform faults that develop perpendicular to the line of the mid-ocean ridge which can offset the ridge line and divide it into segments. The following are examples of <em>mid-ocean ridges</em> found on the floor of the Southern Ocean (see Figure 2).<br>Pacific-Antarctic Ridge (see also Figure 3)"
},
"seamounts": {
"text": "<em>Seamounts</em> (see Figure 1) are submarine mountains at least 1,000 m (3,300 ft) high formed from individual volcanoes on the ocean floor. They are distinct from the plate-boundary volcanic system of the mid-ocean ridges, because <em>seamounts</em> tend to be circular or conical. A circular collapse caldera is often centered at the summit, evidence of a magma chamber within the volcano. Flat topped <em>seamounts</em> are known as <em>guyots</em>. Long chains of <em>seamounts</em> are often fed by \"hot spots\" in the deep mantle. These hot spots are associated with stationary plumes of molten rock rising from deep within the Earth's mantle. These hot spot plumes melt through the overlying tectonic plate as it moves and supplies magma to the active volcanic island at the end of the chain of volcanic islands and <em>seamounts</em>. The following are examples of <em>seamounts</em> found on the floor of the Southern Ocean (see Figure 2).<br>Akopov Seamounts (Figure 3)<br>De Gerlache Seamounts (see also Figure 3, 4)<br>Endurance Ridge (Figure 4)<br>Marie Byrd Seamount (see also Figure 3)<br>Maud Rise (see also Figure 4)<br>Scott Seamounts (see also Figure 3)"
},
"ocean trenches": {
"text": "<em>Ocean trenches</em> (see Figure 1) are the deepest parts of the ocean floor and are created by the process of subduction. Trenches form along convergent boundaries where tectonic plates are moving toward each other, and one plate sinks (is subducted) under another. The location where the sinking of a plate occurs is called a subduction zone. Subduction can occur when oceanic crust collides with and sinks under (subducts) continental crust resulting in volcanic, seismic, and mountain-building processes. Subduction can also occur in the convergence of two oceanic plates where one will sink under the other and in the process create a deep ocean trench. Subduction processes in oceanic-oceanic plate convergence also result in the formation of volcanoes. Over millions of years, the erupted lava and volcanic debris pile up on the ocean floor until a submarine volcano rises above sea level to form a volcanic island. Such volcanoes are typically strung out in chains called island arcs. As the name implies, volcanic island arcs, which closely parallel the trenches, are generally curved. The following are examples of <em>ocean trenches</em> found on the floor of the Southern Ocean (see Figure 2).<br>South Sandwich Trench (also see Figure 4); note - the deepest location in the Southern Ocean"
},
"atolls": {
"text": "note - due to the extremely cold water there are no atolls in the Southern Ocean"
}
},
"Elevation": {
"highest point": {