Who is responsible for the theory of seafloor spreading?
The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960.
What force causes seafloor spreading?
The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones, rather than magma pressure, although there is typically significant magma activity at spreading ridges.
What did Harry Hammond Hess realize in the 1950s when his team continued exploring the ocean floor?
Hess discovered that the oceans were shallower in the middle and identified the presence of Mid Ocean Ridges, raised above the surrounding generally flat sea floor (abyssal plain) by as much as 1.5 km.
Why were magnetic patterns found on the ocean floor puzzling?
Q. Why were magnetic patterns found on the ocean floor puzzling? They showed alternating bands of normal and reversed polarity.
How did the magnetic stripes on the seafloor form?
The striped magnetic pattern develops because, as oceanic crust pulls apart, magma rises to the surface at mid-ocean ridges and spills out to create new bands of ocean floor. Later, after the planet’s magnetic field flips again, the next stripe of new ocean floor aligns its polarity in the opposite direction.
What do sea floor rock patterns indicate about how rock forms?
As new sea floor forms, it records reversals in Earth’s magnetic field. What do sea floor rock patterns indicate about how rock forms? New rock forms at the center of a ridge and then moves away from the center in opposite directions.
How did scientists discover that rocks farther away from the Mid-Ocean Ridge were older?
Answer. Scientist discovered that rocks farther away from the mid-ocean ridge were older than those near it by determining the age of rock samples obtained by drilling on the sea floor.
What is it called when the ocean floor sinks into the mantle?
The process by which the ocean floor sinks into the mantle is called Subduction ..
Why are rocks younger at the Mid-Ocean Ridge than they are farther away from it?
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.