Seafloor spreading slowed 35%, that creates crust
Recently, researchers have done a study related to the spreading or expansion of the seafloor. Globally, sea level spread has slowed by 35%, according to this study by researchers.
For this, the researchers selected 18 vast ridges that were expanding. Under this, the magnetic record recorded in the rocks present on the oceanic crust was studied. Through this they have calculated how much oceanic crust has formed in the last 19 million years.
Key findings of the study:
- The sea level is spreading at the rate of about 140 mm per year. This is less than the average spreading of 200 millimeters per year from 15 million years ago.
- Not all ridges have spread at the same speed. Some had high spreading speed and some were slow.
- The spread of the ridges in the eastern Pacific was slow with a speed of 100 millimeters per year. This has led to a decrease in the global average of sea level variance.
- Two factors have been identified in the report for this slow spreading. First, the rising mountains and second, the change in convection from the mantle.
- Under mantle convection, heat is transported from the interior of the earth towards the surface of the earth.
Seafloor spreading
- It is a geological process. This forms the outermost layer of the earth, that is, the crust.
- Due to the (movement in opposite direction) of two tectonic plates, the vacancy is created. Magma erupts from the Earth’s interior and fills this void. This magma cools to form a new oceanic crust.
- These activities occur near the mid-oceanic ridge. Ridges are large mountain ranges rising above sea level.
Source – The Hindu
