Marine Provinces SG

What is a sounding?

a measured depth of water beneath a ship

What is an echo sounder?

a device that transmits sound from a ship’s hull to the ocean floor where it is reflected back to receivers. The speed of the sound in the water is known, so the depth can be determined from the travel time of the sound signal

Why do seamounts pull water towards the center of their mass?

seamounts have a lot of mass, so they exert a gravitational pull on the water above and around them; essentially, seamounts pull more water toward their center of mass. This causes water to pile up in small but measurable bumps on the sea surface.

How are satellites used to map the ocean floor?

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The sea floor features directly influence Earth’s gravitational field. Deep areas such as trenches correspond to a lower gravitational attraction, and large undersea objects – such as tall volcanoes on the sea floor called seamounts – exert an extra gravitational pull. These differences affect the height of the sea surface directly above these sea features, causing the ocean surface to bulge upward and sink downward, mimicking the relief of the ocean floor.

Does satellite data or echo sounder data create a clearer image of the ocean floor?

Satellite data creates a clearer image of the ocean floor

What is the difference between passive and active continental margins

Passive continental margins do not have a trench, but in active continental margins you do, and more tectonic activity.

What is a continental shelf?

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Flooded extension of the continent

What is a continental slope?

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Marks the seaward edge of the continental shelf and has a relatively steep structure

What is a continental rise?

Found in regions where trenches are absent, where the continental slope merges into a gradual incline.IU

What are turbidity currents and where do you find them?

They are underwater avalanches mixed with rocks and debris. They form on the continental shelf and leaves sediments at the slope base

What is an abyssal plain?

It is the most level place on earth, and is found in all oceans. It extends from the base of continental rise

How are submarine canyons formed?

By the repeated erosion of the slope by turbidity currents flowing down the canyon axis.