Convection Currents Review

What two layers of the Earth take the major roles in the mechanism of Plate Tectonics?

1) Lithosphere is the crust and upper most mantle. (rigid) 2) Asthenosphere is the upper mantle (plastic deformable layer)

Mantle plume

A mantle plume is an upwelling of abnormally hot rock within the Earth's mantle. As the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcanic centers known as hotspots and probably also to have caused flood basalts.

Hawaii Hotspot

Hawaii hotspot is a volcanic hotspot located near the namesake Hawaiian Islands, in the northern Pacific Ocean. One of the most well-known and heavily studied hotspots in the world,[1][2] the Hawaii plume is responsible for the creation of the Hawaiian - Emperor seamount chain, an over 5,800 kilometres (3,600 mi) long chain of volcanoes, four of which are active, two of which are dormant, and more than 123 of which are extinct, many having since been ground beneath the waves by erosion as seamounts and atolls. The chain extends from south of the island of Hawaiʻi to the edge of the Aleutian Trench, near the eastern edge of Russia. While most volcanoes are created by geological activity at tectonic plate boundaries, the Hawaii hotspot is located far from plate boundaries. The classic hotspot theory, first proposed in 1963 by John Tuzo Wilson, proposes that a single, fixed mantle plume builds volcanoes that then, cut off from their source by the movement of the Pacific Plate, become increasingly inactive and eventually erode below sea level over millions of years.

San Andreas Fault

The San Andreas Fault is a continental TRANSFORM fault that extends roughly 1300 km (810 miles) through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal).

Yellowstone Caldera

The Yellowstone region has produced three exceedingly large volcanic eruptions in the past 2.1 million years. In each of these cataclysmic events, enormous volumes of magma erupted at the surface and into the atmosphere as mixtures of red-hot pumice, volcanic ash (small, jagged fragments of volcanic glass and rock), and gas that spread as pyroclastic ("fire-broken") flows in all directions. Rapid withdrawal of such large volumes of magma from the subsurface then caused the ground to collapse, swallowing overlying mountains and creating broad cauldron-shaped volcanic depressions called "calderas."

How do convection currents cause movement of earth's plates?

The entire cycle of heating, cooling, rising, and sinking of rocks in Earth's mantle causes plates to move. Convection currents occur due to molten rock heating up and becoming LESS DENSE, as it gets closer to the surface the molten rock cools down becoming MORE DENSE and sinks. Convection currents are the the movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another