16 terms

Chapter 9 Geography

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earthquake
shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity
focus
the subsurface area where motion of seismic waves is initiated
epicenter
the area at the surface directly above focus
fault
a crack in the earth's crust resulting from the displacement of one side with respect to the other
volcano
a fissure in the earth's crust (or in the surface of some other planet) through which molten lava and gases erupt
crater
a bowl-shaped opening at the top of a volcano
pyroclastic
a rock fragment launched by eruption
3 areas with Volcanic Activity
subduction zones, sea-floor spreading centers and continental rifting, hotspots.
5 types of Volcanic Landforms
cinder cone volcano, caldera/kettle, shield volcano, plateau basalts/flood basalts, composite/strata volcano
cinder cone volcano
cone shaped, cinder accumulate over time
caldera/kettle
an interior sunken portion of a shield or of a composite volcano crater
shield volcano
gradually sloped. large but not steep
plateau basalts/flood basalts
accumulation of horizontal flows formed when lava spreads out of elongated fissures. gentle eruptions
composite/strata volcano
sequence of extensive explosive eruptions
aa
a slow-moving type of lava that hardens to form rough chunks
pahoehoe
a hot, fast-moving type of lava that hardens to form smooth, ropelike coils