What are 3 types of evidence for seafloor spreading?
The pieces of evidence gathered for sea-floor spreading include the evidence from molten material, magnetic stripes, and drilling samples.
What evidence helped prove seafloor spreading?
Harry Hess's hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. This evidence was from the investigations of the molten material, seafloor drilling, radiometric age dating and fossil ages, and the magnetic stripes.
How does seafloor spreading provide evidence of past plate motion?
At first the driving force for spreading was argued to be convection currents in the mantle. Since then, it has been shown that the motion of the continents is linked to seafloor spreading by the theory of plate tectonics, which is driven by convection that includes the crust itself as well.
What are the main features of the seafloor?
There are nine main features of the ocean floor which include (1) continental shelf, (2) continental slope, (3) continental rise, (4) abyssal plains, (5) abyssal hill, (6) mid-ocean ridges, (7) seamounts, (8) deep ocean trenches, and (9) volcanic islands.
How is seafloor spreading an evidence of plate movement?
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.
What discovery about the ocean floor is associated with the seafloor?
It took exploration of the ocean floor to discover sea-floor spreading, the mechanism for the movement of continents that Alfred Wegener lacked. The hypothesis of continental drift gained renewed interest and, when combined with sea-floor spreading, led to the theory of plate tectonics.
How do scientists observe the ocean floor?
Scientists use cameras and sonar near the U.S. Virgin Islands to 'see' the sea floor and find out how fish and other sea life use the underwater habitats, which include coral reefs and sea grasses.
What evidence did Harry Hess use?
He used fossil evidence, such as that of tropical plants found on the Arctic island of Spitzbergen. He found large-scale geographic features that matched, like the Appalachian Mountains in the United States and the Scottish Highlands, as well as rock strata in South Africa that matched those in Brazil.
How do scientist were able to detect the features on the ocean seafloor?
Using Sonar The same principle explains how sonar works. A ship on the surface sends sound waves down to the ocean floor. The sound waves bounce off the ocean floor and return to the surface, like an echo.
What are 3 ways to study the sea floor?
Today's technology lets scientists to study the ocean in a quicker and precise way. There are three tools used to map the ocean floor, sonar, satellites, and submersibles. Sonar is a type of electronic depth-sounding equiptment made in the 1920's.It is an acronym for sound navigation and ranging.
How did Hess discover seafloor spreading?
Hess envisaged that oceans grew from their centres, with molten material (basalt) oozing up from the Earth's mantle along the mid ocean ridges. This created new seafloor which then spread away from the ridge in both directions.
How was the seafloor discovered?
Harry 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.