{"id":40092222,"date":"2022-09-05T12:54:48","date_gmt":"2022-09-05T11:54:48","guid":{"rendered":"https:\/\/chinadialogueocean.net\/?p=92222"},"modified":"2022-11-02T14:01:11","modified_gmt":"2022-11-02T14:01:11","slug":"interactive-mapping-the-wonders-of-the-underwater-world","status":"publish","type":"post","link":"https:\/\/dialogue.earth\/en\/ocean\/interactive-mapping-the-wonders-of-the-underwater-world\/","title":{"rendered":"Interactive: Mapping the wonders of the underwater world"},"content":{"rendered":"\n

To properly map the ocean floor is a long and costly undertaking. Satellites may have already mapped 100% of it, but they have done so in low resolution, missing every feature smaller than 1.5km. So far, only one-fifth has been closely mapped using modern sonar technology, according to UNESCO<\/a>.<\/p>\n\n\n\n

If we consider that the ocean covers more than 70% of the Earth\u2019s surface, that\u2019s a great deal of underwater terrain yet to be well explored. A growing movement is trying to change this. In the last five years, the amount of seafloor mapped in great detail has risen from 6% to 20%. Earlier this year, UNESCO announced<\/a> it will partner with countries and companies to try and take that up to 80% by 2030. Various technological innovations, such as sonar attached to autonomous vessels, are opening up new avenues for progress towards that goal.

In their expeditions, ocean explorers have found very complex landscapes: thousands of impressive underwater features including lofty mountain ridges and incredibly deep trenches. It\u2019s possible to split these features into seven main kinds:<\/p>\n\n\n\n

\"illustration<\/div>
Graphic by China Dialogue Ocean. Based on a figure<\/a> in The Law of Seabed (2020).<\/div><\/div><\/div><\/div>\n\n\n\n

Abyssal plains<\/h3>\n\n\n\n

The huge flat bottoms of the deep ocean. Covered by fine-grained sediment like clay and silt, abyssal plains are also peppered with \u201cabyssal hills\u201d and underwater mountains known as seamounts.<\/p>\n\n\n\n

Continental shelves<\/h3>\n\n\n\n

The underwater extension of a continent \u2013 usually wide along low-lying land and narrow along mountainous coasts.<\/p>\n\n\n\n

Continental slopes<\/h3>\n\n\n\n

The sloped bottom of the ocean that extends from the continental shelf down to the abyssal plain.<\/p>\n\n\n\n

Mid-ocean ridges<\/h3>\n\n\n\n

Mountain ranges on the ocean floor that mark the boundaries between tectonic plates, where magma wells up and new ocean floor is formed.<\/p>\n\n\n\n

Seamounts<\/h3>\n\n\n\n

A mountain, usually formed of volcanoes, rising from the seafloor but not reaching above the surface of the water.<\/p>\n\n\n\n

Trenches<\/h3>\n\n\n\n

The deepest parts of the ocean, trenches are formed by subduction \u2013 when a tectonic plate slides beneath another and forms a steep V-shaped depression. The world\u2019s deepest point lies in the Mariana Trench in the Pacific Ocean. Known as Challenger Deep, it is more than 2,000 metres further from sea level than the Earth\u2019s highest point, Mount Everest.<\/p>\n\n\n\n

Submarine canyons<\/h3>\n\n\n\n

Narrow, steep-sided valleys that cut into continental slopes. They have steep rocky sides that can be thousands of metres tall. Those of the Grand Bahama Canyon, which are thought to be the highest, rise nearly 5km from the canyon floor. The walls of the Grand Canyon in Colorado, by comparison, measure about 1.6km at their tallest. Submarine canyons are found along continental slopes, unlike trenches, which tend to be deeper down where tectonic plates meet.<\/p>\n\n\n\n

The interactive map below shows the locations of some of these features. Click on the circles and lines to find out more about them.<\/p>\n\n\n\n