where most volcanoes form
What is at subduction zones?
This is the first wave to reach a seismograph
What is a primary wave?
this is the name for the crack or opening from which magma or gases make their way to the surface
What is a vent?
This type of boundary slides occurs where two plates slide by each other
What is transform plate boundary?
this is the best example of a transform plate boundary
What is the San Andreas fault?
occurs at divergent oceanic plates
What is the formation of new land?
This is the initial surface location of an earthquake
What is the epicenter?
This is the process of rebuilding pressure in a volcano after an eruption
What is recharging?
This is what the edges of all plates are called
What is a plate boundary?
This is one of the better examples of a hotspot volcano
What is either Yeloowstone or the Hawaiian Islands?
caused by the splitting of the Somali plate from the African plate
What is the East African Rift ( location of the Great Rift Valley )?
This is an instrument that measures the size ( magnitude ) of an earthquake
What is a seismograph?
This is a volcano that has not erupted in the past 10,000 years but is expected to erupt again
What is dormant?
this is where the lithosphere floats, causing its breakup into smaller pieces
What is the athenosphere?
This is an eruptive volcano in Washington state
What is either Mt. St. Helen's or Mt. Rainier?
These do not form at plate boundaries and are found most often in the middle of a tectonic plate
What are hotspot volcanoes?
This measures the amplitude of the highest S wave; each increase in number corresponds to an increase of 33 times the energy
What is the Richter Scale?
These are the four categories of volcano shapes: shield, composite , dome and
What is cindercone?
this is the plate activity which ends in orogeny
What is convergence of continental to continental plates?
This is the largest tectonic plate
What is the Pacific Plate?
The Ring of Fire is a great example of this type of plate boundary
What is a convergent plate boundary ( subduction zone )
This is the location at which an earthquake begins underground
What is the focus?
Mt. Pinatubo is a volcano that erupted in 1991. This was odd for this reason
What is geologists believed it was extinct?
these two things forms at the oceanic to oceanic subduction of two plates
What are trenches and island arc volcanoes?
This is the result of a divergent plate boundary and is visible on dry land and under water on and near Iceland
What is the Mid-Atlantic Ridge?