volcanos and earthquakes Flashcards
ring of fire
Volcanoes are associated with the belt throughout its length; for this reason it is called the “Ring of Fire
Strike-slip fault
Strike-slip faults are vertical (or nearly vertical) fractures where the blocks have mostly moved horizontally
Normal fault
Normal, or Dip-slip, faults are inclined fractures where the blocks have mostly shifted vertically
Reverse fault
In the field of geology, a reverse fault is a dip-slip fault in which the hanging wall moves upwards, relative to the footwall
P-waves
P waves, or Primary waves, are the first waves to arrive at a seismograph
S-waves
S waves also called secondary waves and shear waves, are the second waves to hit the seismographs
epicenter
the point on the earth’s surface vertically above the focus of an earthquake.
focus
the center of interest or activity.
Richter magnitude scale
Richter scale (ML), quantitative measure of an earthquake’s magnitude (size), devised in 1935 by American seismologists Charles F. Richter and Beno Gutenberg
explosive volcano
an explosive eruption is a volcanic eruption of the most violent type
nonexplosive volcano
Non-explosive volcanic eruptions generally occur when magma is thin and flows easily. Lava flows out of the volcano
Krakatoa
one of the deadliest and most destructive volcanic events in recorded history
Yellowstone supervolcano
Although another catastrophic eruption at Yellowstone is possible, scientists are not convinced that one will ever happen
San Andreas fault
major fracture of the Earth’s crust in extreme western North America
Mid-oceanic ridge
an elevated region with a central valley on an ocean floor at the boundary between two diverging tectonic plates where new crust forms from upwelling magma
