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The asthenosphere is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth. It lies below the lithosphere, at depths between approximately 80 and 200 km below the surface.  The asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth’s surface.  The asthenosphere is now thought to play a critical role in the movement of plates across the face of Earth's surface. According to plate tectonic theory, the lithosphere consists of a relatively small number of very large slabs of rocky material.
Caldera The Yellowstone Caldera is a volcanic caldera and super volcano in Yellowstone National Park in the Western United States, sometimes referred to as the Yellowstone Super volcano.  caldera is a large cauldron-like hollow that forms following the evacuation of a magma chamber/reservoir. When large volumes of magma are erupted over a short time, structural support for the crust above the magma chamber is lost.  There are about 20 known super volcanoes on Earth - including Lake Toba in Indonesia, Lake Taupo in New Zealand, and the somewhat smaller Phlegraean Fields near Naples, Italy. Super-eruptions occur rarely - only once every 100,000 years on average.
Craton North American Craton. The stable core of the continent is the North American Craton. Much of it was also the core of an earlier supercontinent, Laurentia. The part of the craton where the basement rock is exposed is called the Canadian Shield.  The term craton is used to distinguish the stable portion of the continental crust from regions that are more geologically active and unstable. Cratons can be described as shields, in which the basement rock crops out at the surface, and platforms, in which the basement is overlaid by sediments and sedimentary rock. 
Deep Earthquake Normal rocks are ductile, or pliable, at these great depths because of high temperature and thus aren't able to rupture in an abrupt fashion to produce deep earthquakes, which occur below subduction zones where two tectonic plates collide at ocean trenches.  The deepest earthquakes occur within the core of subducting slabs - oceanic plates that descend into the Earth's mantle from convergent plate boundaries, where a dense oceanic plate collides with a less dense continental plate and the former sinks beneath the latter.  Deep earthquakes pack enormous energy that transfers to other areas where other quakes will strike.   Below the waters north of New Zealand is one of many deep earthquake areas where earthquakes occur frequently. 
Hotspots In geology, a hotspot or hot spot is a portion of the Earth's surface which experiences volcanism. This may be caused by a rising mantle plume or some other cause. Hotspots may be far from tectonic plate boundaries. A volcanic hotspot is where lava pushes up from under the mantle and creates a volcano.  34 biodiversity hotspots have been identified. They once covered 15.7 percent of the Earth's land surface. 86 % of the hotspots' habitat has already been destroyed. The intact remnants of the hotspots now cover only 2.3 % of the Earth's land surface.  Vocanoes eruptions are on the increase in recent years and hotspots have influence in climate change. 
Juan de Fuca fault The Juan de Fuca Plate is a tectonic plate generated from the Juan de Fuca Ridge and is subducting under the northerly portion of the western side of the North American Plate at the Cascadia subduction zone.  The Juan de Fuca plate is bounded on the south by the Blanco Fracture Zone (running northwest off the coast of Oregon), on the north by the Nootka Fault (running southwest off Nootka Island, near Vancouver Island, British Columbia) and along the west by the Pacific Plate (which covers most of the Pacific Ocean and is the largest of Earth's tectonic plates).    The Juan de Fuca Plate is still actively subducting beneath N. America. Its motion is not smooth, but rather sticky; strain builds up until the fault breaks and a few meters of Juan De Fuca slips under North America in a big earthquake. This action takes place along the interface between the plates from the Juan de Fuca Trench off shore down-dip until the fault is too weak to store up any elastic stress. The locked zone varies in width from a few tens of kilometers (km) along the Oregon coast to perhaps a hundred km or more off of Washington's Olympic Penninsula, and is about 1,000 km long. It takes a lot of slip (10s of meters) over a very large area to generate the M9 subduction zone earthquakes that rock the region ~ every 550 years on average.
Subduction Zone  A subduction zone is the biggest crash scene on Earth. These boundaries mark the collision between two of the planet's tectonic plates. The plates are pieces of crust that slowly move across the planet's surface over millions of years.   Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle.   There are two types of plates: continental and oceanic. Oceanic plates are made of mafic or basaltic rock. Continental plates are made of felsic or granitic rock. The main features of subduction zones include ocean trenches, volcanoes, and mountains. Subduction zone volcanism occurs where two plates are converging on one another. One plate containing oceanic lithosphere descends beneath the adjacent plate, thus consuming the oceanic lithosphere into the earth's mantle. This on-going process is called subduction.