Arthur holmes in 1930s discussed the possibility of convection currents.
Seafloor spreading theory year.
The mid ocean ridge curves like the seams of a baseball along the sea floor extending into all of earth s oceans.
These cornerstones are convectional current theory and paleomagnetism.
As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.
These age data also allow the rate of seafloor spreading to be determined and they show that rates vary from about 0 1 cm 0 04 inch per year to 17 cm 6 7 inches per year.
To understand the concept of seafloor spreading we must first understand some basic concepts that form the cornerstones for the concept of seafloor spreading.
Supporters of continental drift originally theorized that the continents moved drifted through unmoving oceans.
The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age.
Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch.
The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones rather than magma pressure although there is typically.
Seafloor spreading proves that the ocean itself is a site of tectonic activity.
Mapping the mid ocean ridge the east pacific rise is just one part of the mid ocean ridge the longest chain of mountains in the world.
Sea floor spreading theory.
Seafloor spreading helps to explain continental drift in the theory of plate tectonics.
Sea floor spreading powerpoint 1.
At spreading rates of about 15 cm 6 inches per year the.
Most of the mountains in the mid ocean ridge lie hidden under hundreds of meters of.
Seafloor spreading disproves an early part of the theory of continental drift.
That is it explains why the age thickness and density of the oceanic crust increases with distance from the mid oceanic ridge.
Convection current theory convection current theory is the soul of seafloor spreading theory.
Harry hess s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory.
As per seafloor spreading theory the mid oceanic ridge is the region where at the crest of oceanic ridges through the rupture of the oceanic crust and the crack continuous new lava eruption thrusts into it consequently pushing the oceanic crust on either side.
The theory of sea floor spreading states that new oceanic crust is being formed continuously at mid oceanic ridges while the older rocks move away from the ridge.
When oceanic plates diverge tensional stress causes fractures to occur in the lithosphere.
This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century.
It leads to the formation of new material on the ridge.
Evidence of sea floor spreading.