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What is 1 + 3?
Ch. 10 Earthquakes
Where do the deepest earthquakes occur?
Name 3 parts of a seismograph:
bell drum pen (PEN does not move)
What's the minimum # of seismograph stations needed to pinpoint an epicenter?
What can 1 seismograph station determine by itself?
Earthquake distance from THAT station and magnitude
What data helps scientists locate a seismic gap?
foci of previous earthquakes along fault
Richter Scale measures:
magnitude (strength) of earthquake
What is the difference between a Richter 4 and Richter 6 earthquake (in terms of energy)?
Richter 6 is (31x31) times stronger than Richter 4
Where does Mohorovicic discontinuity occur?
Between the crust and mantle
What causes most major earthquakes?
Strain that builds up along faults (boundaries) that is then released when plates shift
Primary (first); fastest; travel through any substance (dirt, air, liquid, rock)
secondary; slower than P-Waves; cannot travel through liquid/gas; cause rocks to move at RIGHT ANGLES to the wave direction
travel on Earth's surface;slower than P or S waves
What is the shadow zone?
wide belt on opposite side of Earth than the earthquake; no waves travel here
What is separated at TRANSITION ZONE?
upper mantle from denser lower mantle
can have more than 1000/day; decrease in frequency over time
New Madrid, Missouri
1 of the most seismically active places in the world! No boundaries are here either -- how odd!
What happens when a tsunami approaches shallow water?
Speed slows down but height increases!