What Is It Called When The Ocean Floor Sinks Into The Mantle?

What is the molten material that rises from the mantle?

Magma exists as pockets and plumes beneath the surface of the Earth.

Magma is usually studied as lava or igneous rock.

But most magma remains molten or partly molten beneath Earth’s surface.

In fact, magma has only been discovered three times in its “natural” habitat deep in Earth’s crust..

What causes seafloor spreading?

Sea-floor spreading is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. As the plates move apart, new material wells up and cools onto the edge of the plates.

What is the feature on the ocean floor at C called?

deep Ocean FrenciaThe feature on the ocean floor at C is called a(n) deep Ocean Frencia . 8. The process that continually adds new material to the ocean floor is – called Sea floor spreading.

What part of the ocean is the deepest?

Challenger DeepOcean/Deepest parts

What happens to old oceanic crust as new molten material rises from the mantle?

What happens to old oceanic crust as new molten material rises from the mantle? It is recycled back into the mantle through the process of subduction. The process of subduction also plays a role in the new molten material rising from the mantle (see page 132).

How does sea floor spreading add material to the ocean floor?

Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor.

Who discovered seafloor spreading?

Harry HessHarry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains, perhaps sunken islands, shape the Pacific floor.

What is the process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle is called?

At some points, the oceanic crust bends downward and forms a deep-ocean trench. Then the oceanic crust sinks back into the mantle through a process called subduction. … Subduction allows part of the ocean floor to sink back into the mantle over tens of millions of years.

What device do scientists use to map the ocean floor?

SonarDive and Discover : Oceanographic Tools: Sonar. Echo sounding is the key method scientists use to map the seafloor today. The technique, first used by German scientists in the early 20th century, uses sound waves bounced off the ocean bottom.

Why are rocks next to the Mid Ocean Ridge younger than those farther away from the ridge?

How did scientists discover that rocks farther away from the mid-ocean ridge were older that those near the ridge? Oceanic crust near the mid-ocean ridge is younger than the crust farther from the ridge. … The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle.

How are ocean trenches formed?

In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.

What is the process that continually adds new material to the ocean floor?

sea-floor spreadingIn 1960, Hess proposed a radical idea. He suggested that a process he called sea-floor spreading continually adds new material to the ocean floor. In sea-floor spreading, the sea floor spreads apart along both sides of a mid-ocean ridge as new crust is added.

Which part of the ocean floor is the flattest?

abyssal plainsAnswer and Explanation: The flattest portion of the ocean is known as the abyssal plains.

Is it true that a deep ocean trench is an underwater mountain?

A deep-ocean trench is an underwater MOUNTAIN. Molten material erupts INSIDE the central valley of mid-ocean ridges. The farther from a mid-ocean ridge a rock sample is taken, the YOUNGER the rock is. Sea-floor spreading occurs at MID-OCEAN RIDGES.

What are the 3 types of evidence for seafloor spreading?

Several types of evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves. This evidence led scientists to look again at Wegener’s hypothesis of continental drift.

What are 4 types of ocean floor?

Lesson SummaryStudying the ocean floor is difficult because the environment is so hostile. … Features of the ocean floor include the continental shelf and slope, abyssal plain, trenches, seamounts, and the mid-ocean ridge.The ocean floor is rich in resources.

Why is the ocean floor so difficult?

Why is much of the ocean floor so difficult to see? … In the movie, Tim says that ocean currents deposit sediment on the ocean floor.