auto-update week 46

oceans/xo.json

@@ -29,9 +29,6 @@
     "Climate": {
       "text": "northeast monsoon (December to April), southwest monsoon (June to October); tropical cyclones occur during May/June and October/November in the northern Indian Ocean and January/February in the southern Indian Ocean"
     },
-    "Terrain": {
-      "text": "<p>surface dominated by a major gyre (broad, circular system of currents) in the southern Indian Ocean and a unique reversal of surface currents in the northern Indian Ocean; ocean floor is dominated by the Mid-Indian Ocean Ridge and subdivided by the Southeast Indian Ocean Ridge, Southwest Indian Ocean Ridge, and Ninetyeast Ridge</p> <p><strong>major surface currents:</strong> the counterclockwise Indian Ocean Gyre comprised of the southward flowing warm Agulhas and East Madagascar Currents in the west, the eastward flowing South Indian Current in the south, the northward flowing cold West Australian Current in the east, and the westward flowing South Equatorial Current in the north; a distinctive annual reversal of surface currents occurs in the northern Indian Ocean; low atmospheric pressure over southwest Asia from hot, rising, summer air results in the southwest monsoon and southwest-to-northeast winds and clockwise currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and counterclockwise currents</p>"
-    },
     "Ocean volume": {
       "ocean volume": {
         "text": "264 million cu km"
@@ -40,6 +37,32 @@
         "text": "19.8%"
       }
     },
+    "Major ocean currents": {
+      "text": "The counterclockwise Indian Ocean Gyre comprised of the southward flowing warm Agulhas and East Madagascar Currents in the west, the eastward flowing South Indian Current in the south, the northward flowing cold West Australian Current in the east, and the westward flowing South Equatorial Current in the north; a distinctive annual reversal of surface currents occurs in the northern Indian Ocean; low atmospheric pressure over southwest Asia from hot, rising, summer air results in the southwest monsoon and southwest-to-northeast winds and clockwise currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and counterclockwise currents"
+    },
+    "Bathymetry": {
+      "continental shelf": {
+        "text": "<p>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. The following are examples of features found on the <em>continental shelf</em> of the Indian Ocean (see Figure 2).</p> <p>Exmouth Plateau<br>Indus Canyon <br>The Swatch of No Ground/Ganges Canyon (Bay of Bengal)<br>Sunda Shelf</p>"
+      },
+      "continental slope": {
+        "text": "<p>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. 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 Indian Ocean (see Figure 2).</p> <p>Bengal Fan<br>Indus Fan</p>"
+      },
+      "abyssal plains": {
+        "text": "<p>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 Indian Ocean (see Figure 2).</p> <p>Arabian Basin<br>Crozet Basin<br>Madagascar Basin<br>Mid-Indian Basin<br>Mozambique Basin<br>Wharton Basin</p>"
+      },
+      "mid-ocean ridge": {
+        "text": "<p>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 Indian Ocean (see Figure 2).</p> <p>Central Indian Ridge<br>Davie Ridge<br>Southeast Indian Ridge<br>Southwest Indian Ridge</p>"
+      },
+      "seamounts": {
+        "text": "<p><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 Indian Ocean (see Figure 2).</p> <p>Andaman-Nicobar Ridge<br>Chagos-Laccadive Ridge<br>Kerguelen Plateau<br>Madagascar Plateau<br>Mascarene Plateau<br>Mozambique Plateau<br>Ninetyeast Ridge<br><br></p>"
+      },
+      "ocean trenches": {
+        "text": "<p><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 Indian Ocean (see Figure 2).</p> <p>Java/Sunda Trench; note - deepest point in the Indian Ocean</p>"
+      },
+      "atolls": {
+        "text": "<p><em>Atolls</em> (see Figure 1) are the remains of dormant volcanic islands. In warm tropical oceans, coral colonies establish themselves on the margins of the island. Then, over time, the high elevation of the island collapses and erodes away to sea level leaving behind an outline of the island in the form of the fringing coral reef. The resulting low island is typified by the coral reef surrounding a low elevation of sand and coral above sea level with an interior shallow lagoon. Often times the remaining dry land is broken into a ring of islets. Some lagoons can be hundreds of square kilometers. It may take as long as 300,000 years for an atoll formation to occur. <em>Guyots</em> are submerged atoll structures, which explains why they are flat topped seamounts. The following are examples of <em>atolls</em> found in the Indian Ocean (see Figure 2).</p> <p>Bassas da India<br>Chagos Archipelago/Diego Garcia<br>Europa Island<br>Juan de Nova Island<br>Lakshadweep Islands<br>Maldive Islands<br>Seychelles</p>"
+      }
+    },
     "Elevation": {
       "highest point": {
         "text": "sea level"