The Ocean Floor By: Emily Ehrenburg

Key Terms:

Continental Shelf- the flattest part of the continental margin.

Continental Slope- the steepest part of the continental margin.

Continental Rise- the base of the continental slope.

Abyssal Plain- the broad, flat portion of the deep-ocean basin.

Mid-ocean Ridge- a long mountain chain that forms on the ocean floor where tectonic plates pull apart; usually extends along the center of ocean basins.

Rift Valley- a valley that forms in a rift zone between mountains.

Seamount- an individual mountain of volcanic material on the abyssal plain.

Ocean Trench- a deep trough in the deep-ocean basin that forms where one oceanic plate is forced underneath a continental plate or another oceanic plate.

Scientists have questions about the ocean like "how deep is the ocean" or "what exactly is at the bottom of the ocean?" Scientists have been able to explore some of the ocean but the rest of it remains a mystery. Scientists use Alvin a underwater mini-sub and Deep Flight which is an underwater airplane to uncover new species or other new things. Alvin and Deep Flight can transport scientists to some of the deepest parts of the ocean. What you might see underwater can be the worlds largest mountain chains and canyons which can be deeper than places like the Grand Canyon. The land under the ocean is divided into two major regions which are the continental margin which is made of continental crust. The second major region is the deep-ocean basin which is made of oceanic crust.

The continental margin is divided into the continental shelf, continental slope, and the continental rise. The deep-ocean basin is made of the abyssal plain which also contains features known as mid-ocean ridges, rift valleys, and also ocean trenches. There can also be over a thousand seamounts that are not located near plate boundaries.

Scientists use technologies such as sonar and satellites to look at the ocean floor without going underwater. Sonar stands for sound navigation and ranging. Sonar is based on the echo-ranging behavior of bats. Sonar verifies how deep the ocean is by sending high-frequency sound pulses down to the ocean and then it bounces off the ocean floor and returns back to the surface. Scientists calculate how deep the ocean is by multiplying half the time it took to travel by the speed of sound in the water.

Landsat 1 is a satellite that orbits the earth and it sends back information to scientists about the earths resources. Another satellite scientists use is Seasat and it sends images back that lets scientists measure the direction and speed of the oceans current and it also identifies any changes in the polar icecaps. Geosat was a satellite that has been used to find any small change in the height of the oceans surface. Mountains and trenches change the height of the ocean. By using the topography of the ocean floor scientists measure the height of the oceans surface and use that to make maps of the ocean floor. The difference between ship-based sonar readings and satellites is that scientists get more information back with satellites because the satellites send back more territory to make maps.


Created with images by joakant - "coral underwater oasis ocean floor" • Saltvand - "Bubbles" • NOAA's National Ocean Service - "Kelp Forest" • leigh_householder - "017_17" • skeeze - "ice wall sea floor antarctica" • Fancy Horse - "Underwater Spiraling (Fish)"

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