Earthquakes and Volcanoes Flashcards
fault
a break in a body of rock along which one block slides relative to another
ring of fire
a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur
transform / strike-slip
occurs where two plates slip past each other, transform motion creates srtike-slip faults
divergent / normal
the boundary between to tectonic plates that are moving away from each other
convergent / reverse
the boundary formed by the collision of two lithosphere plates
P-waves
a seismic wave that causes particles of rock to move in a back and forth direction
S-waves
a seismic wave that causes particles of rock to move in a side to side direction
epicenter
the point on earths surface directly above an Earthquakes starting point
focus
the point along a fault at which the first motion of an earthquake occurs
Richter scale
measures the ground motion from an earhquake and adjusts for distance to find its strength
explosive volcano
volcanic eruptions can be explosive, sending ash, gas and magma high up into the atmosphere, or the magma can form lava flows, which we call effusive eruptions. Whether an eruption is explosive or effusive largely depends upon the amount of gas in the magma.
nonexplosive volcano
the composition of magma is different in different volcanoes, the properties of the lava are different. In effusive eruptions, lava flows are relatively calm and do not explode out of the volcano.
Krakatoa
a volcanic island situated in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung
Yellowstone supervolcano
a volcanic caldera
San Andreas fault
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 long undersea mountain chain that forms along the floor of the major oceans
shield volcano
built from layers of lava released from repeated non explosive eruptions
cinder cone volcano
material forms steep slopes and only erupt for a short time
composite volcano
most common, form from explosive eruptions of pyroclastic material followed by quieter flows of lava
hot spot
a volcanically active area of earths surface far from a tectonic plate boundary
