earthquakes. berks county earthquakes sinking spring – 12 /13/06 felt at wilson southern 2.8...
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Berks County Earthquakes
• Sinking Spring – 12 /13/06 Felt at Wilson Southern 2.8
• Spring Township 10/29/96 2.5
• Spring Town. 2/1/96 2.3 and 4 more
• Whitfield 1/15/94 4.6
• Sinking Spring 1/7/54 4.0
Earthquakes in Pennsylvania
• Web Sites
• Maps of PA
• Maps of Eastern U.S.
• Earthquake Map of U.S.
• Real-Time Seismograph from Millersville
Earthquakes
• Rocks bend, compress, and stretch from movement caused by forces in the Earth.
• Earthquakes can not be accurately predicted.
Earthquake Vocabulary
• Shadow zone: a region that does not receive any earthquake waves
• Richter Scale – evaluates earthquake energy.
• Mercalli Scale – evaluates earthquake damage.
• Seismologist – scientist who studies earthquakes
Earthquake Vocabulary
• P-Wave = primary,arrive first, move in the direction of the wave .
• Secondary Waves = particles in rocks move at right angles to the direction of movement.
• Epicenter = The point on the Earth’s surface which is directly above the focus.
• Focus = The point in the Earth’s interior where energy is released.
Earthquake Vocabulary
• Faults – once the elastic
limit of rocks is passed,
• they break and move along
surfaces called faults.
Earthquakes• Magnitude- each level is 32 times more powerful;
8 is 32 x more powerful than a 7.• A Seismograph measures Magnitude.
• Compression – a force that squeezes and compresses.
Vocabulary
• Tension – is the stress that causes stretching and elongation.
• Shear – is the force that causes slippage and sliding.
Faults
• Normal Faults – are caused
by tensional forces.
• Reverse Faults – are caused
by compression forces.
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