What is the history of seafloor spreading?
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 are the steps of seafloor spreading in order?
Terms in this set (7)
- Magma comes out of the rift valley.
- Magma cools to rock and hardens.
- Rock is pushed away as new rock is formed at MOR.
- Oceanic crust and continental crust meet at the trench.
- Oceanic crust bends down under the continental crust.
- Gravity pulls rock towards mantle.
- Rock melts to mantle.
Where does the seafloor spreading take place?
the mid-oceanic ridge
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 are the 3 types of seafloor spreading?
There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide, divergent, where plates separate, and transform motion, where plates simply slide past each other.
Who first gave the idea of sea floor spreading?
Harry Hess: One of the Discoverers of Seafloor Spreading.
What new technology was used to map the seafloor beginning in the 1940s and 1950s?
Beginning in the 1950s scientists using magnetic instruments (magnetometers) adapted from airborne devices developed during World War II to detect submarines began recognizing odd magnetic variations across the ocean floor.
Which is first step in the seafloor spreading process?
1. A long crack in the oceanic crust forms at a mid ocean ridge. 2. Molten material rises and erupts along the ridge.
What is the age of the oldest seafloor?
The oldest seafloor is comparatively very young, approximately 280 million years old. It is found in the Mediterranean Sea and is a remnant of an ancient ocean that is disappearing between Africa and Europe.
Who mapped out the ocean floor in 1952?
Tharp and Heezen began mapping the individual ocean floors in 1952, but found obstacles in their way.
When did we map the sea floor?
The first detailed map of the ocean’s bottom in 1957 helped revolutionize our understanding of the geology of the seafloor—and contributed directly to the development of the theory of plate tectonics.
When did we map the ocean floor?
The publication of Heezen and Tharp’s Physiographic Map of the North Atlantic in 1957 was the first map of the sea floor that enabled the general public to begin to visualize what the ocean floor really looked like.
What is seafloor spreading?
Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.