Earthquakes and Volcanoes Flashcards
ring of fire
a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
Strike-slip fault
a fault in which rock strata are displaced mainly in a horizontal direction, parallel to the line of the fault.
Normal fault
a type of dip-slip fault where the hanging wall moves downwards from the footwall.
Reverse fault
the block above the fault moves up relative to the block below the fault
P-waves
one of the two main types of elastic body waves, called seismic waves in seismology.
S-waves
transverse waves that travel slower than P-waves.
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
a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 paper, where he called it the “magnitude scale”
explosive volcano
an explosive eruption is a volcanic eruption of the most violent type.
nonexplosive volcano
appears to result from rapid, sub-surface gas release from magma ascending as a permeable foam.
Krakatoa
a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung
Yellowstone supervolcano
a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States
San Andreas fault
a continental transform fault that extends roughly 1,200 kilometers through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip
Mid-oceanic ridge
a seafloor mountain system formed by plate tectonics. It typically has a depth of about 2,600 meters and rises about 2,000 meters above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary
shield volcano
a broad domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava.
cinder cone volcano
a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent
composite volcano
a composite volcano, is a conical volcano built up by many layers of hardened lava and tephra.
hot spot
a small area or region with a relatively hot temperature in comparison to its surroundings.
Mt. Vesuvius
a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about 9 km east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc
