Seismic waves are used to map the earth's structure.
What is slab-pull?
The mid-ocean ridge pulling plates together.
Newly formed plates becoming denser and thicker at a mid-ocean ridge, causing the mantle to sink under its own weight.
Slabs of rock being pulled side to side as an S wave moves them horizontally, causing scarring to the land, and massive erosion.
Approximately every 400,000 years the magnetic fields of the earth change direction, resulting in the north pole and the south pole swapping.
As seafloor spreading produces new crust, what occurs to the excess crust left behind?
It is left on the earth, causing gradual growth over thousands of years.
It is weathered by biological matter, or eroded by water.
It is subducted, melting in an area known as the subduction zone.
It is mined for resources, farmed like fruits or vegetables.
Plate boundary collision/contact is the only reason a Volcano may occur.
