Download Ch 12 Earthquakes PowerPoint

Ch 12 Earthquakes PowerPoint
Slide 2: An earthquake is the vibration of Earth produced by the rapid release of_____________.
_____________ is the point within Earth where the earthquake starts. _______________ is the location on the
surface directly above the focus. Faults are ___________________ in Earth where movement has occurred.
Slide 3-4: n/a
Slide 5: Elastic Rebound __________________ says that most earthquakes are produced by the rapid release of
elastic _______________ stored in _______________ that has been subjected to great forces. When the
strength of the rock is_________________, it suddenly breaks, causing the vibrations of an earthquake.
Slide 6: n/a
Slide 7: Aftershocks and Foreshocks- An __________________ is a small earthquake that follows the main
earthquake. A ___________________ is a small earthquake that often precedes a major earthquake.
Slide 8: Seismographs are instruments that record earthquake waves. _________________ are traces of
amplified, electronically recorded ground motion made by seismographs. ________________ waves are seismic
waves that travel along Earth’s outer layer.
Slide 9-10: n/a
Slide 11: Body Waves- Identified as P waves or S waves, _______________ are push-pull waves that push
(compress) and pull (expand) in the direction that the waves travel, travel through solids, liquids, and gases, - Have
the greatest _________________ of all earthquake waves
Slide 12: S Waves- Seismic waves that travel along Earth’s _______________ layer, Shake particles at right
angles to the direction that they travel, Slower velocity than P waves, travel only through______________, A
seismogram shows all three types of seismic waves—surface waves, P waves, and S waves.
Slide 13: What do S waves cause the ground to do?
What do P waves cause the ground to do?
Slide 14: Earthquake Distance- The ________________ is located using the difference in the arrival times
between P and S wave recordings, which are related to distance. Earthquake Direction- Travel-time graphs from
three or more seismographs can be used to find the exact location of an earthquake epicenter. Earthquake ZonesAbout _________ percent of the major earthquakes occur in a few narrow zones.
Slide 15: n/a
Slide 16: Historically, scientists have used two different types of measurements to describe the size of an
earthquake —___________________ and magnitude. Richter Scale- Based on the amplitude of the largest
seismic wave. Each unit of Richter magnitude equates to roughly a _________________ energy increase.
Slide 17: Moment Magnitude is derived from the amount of __________________ that occurs along the fault
zone, Moment magnitude is the most widely used measurement for earthquakes because it is the only magnitude
scale that estimates the energy released by earthquakes. It measures very large earthquakes.
Slide 18 - 19: n/a
Slide 20: The damage to buildings and other structures from earthquake waves depends on several factors. These
factors include the ___________________ and duration of the vibrations, the nature of the material on which
the structure is built, and the __________________of the structure.
Slide 21: n/a
Slide 22: Building Design- Factors that determine structural damage are : intensity of the earthquake, nature of
the _______________ upon which the structure rests, design of the structure, unreinforced stone or brick
buildings are the most serious _________________ threats
Slide 23: Liquefaction- saturated material turns______________, underground objects may float to the surface
Slide 24: n/a
Slide 25: Tsunamis- A tsunami triggered by an earthquake occurs where a slab of the _______________ floor is
displaced vertically along a fault. A tsunami also can occur when the ________________ of a quake sets an
underwater landslide into motion. Tsunami is the Japanese word for “seismic sea wave.”
Slide 26: n/a
Slide 27: Tsunami Warning System- Large earthquakes are reported to Hawaii from Pacific seismic stations.
Although _________________ travel quickly, there is sufficient time to evacuate all but the area closest to the
epicenter.
Slide 28: Other Dangers: Landslides- With earthquakes, the greatest damage to structures is from
____________________ and ground subsidence, the sinking of the ground triggered by vibrations. Fire- The
San Francisco earthquake of 1906, most of the destruction was caused by _________________ that started
when gas and electrical lines were cut.
Slide 29: n/a
Slide 30: Predicting earthquakes- Short-Range predictions: So far, methods for short-range predictions of
earthquakes have ________________ been successful. Long-Range predictions: Scientists don’t yet understand
enough about how and where earthquakes will occur to make ________________ long-term predictions. A seismic
gap is an area along a fault where there has not been any earthquake activity for a long period of time.
Slide 31-32: n/a