USGS Earthquake Hazards Program Earthquakes U S Department

USGS Earthquake Hazards Program Earthquakes U. S. Department of the Interior U. S. Geological Survey

Plate Boundaries

Plate Tectonics USGS Earthquake Hazards Program Lisa Wald USGS Pasadena U. S. Department of the Interior U. S. Geological Survey

Global Distribution of Earthquakes

Pacific-North American Plate Boundary

The San Andreas Fault

Three Types of Faults Strike-Slip Reverse Normal

Strike-slip Fault Example

Strike-slip Fault Example 1906 San Francisco Earthquake

Normal Fault Example Dixie Valley-Fairview Peaks, Nevada earthquake December 16, 1954

Reverse Fault Example

Is there such a thing as “Earthquake Weather”? ? ?

Bigger Faults Make Bigger Earthquakes

Bigger Earthquakes Last a Longer Time

View EQ Damage • http: //www. youtube. com/watch? v=d. LWN 7 AHft. Bo&feature=related • http: //www. youtube. com/watch? v=_Ktx. Cc. S 7 NNw&feature=related Questions to think about while viewing: • What is released when an EQ occurs? • Where does this energy go? • How do we record the information about this energy?

Seismic Waves

Primary Wave - Fast wave!

Secondary Waves Can only travel through solid material

Long Wave (or L wave) - Converted S & P wave energy - Slowest wave

Summary • Secondary waves do not travel through liquids, only solids • Primary waves arrive first, followed by Secondary waves. • Seismologists know how fast seismic waves travel, and this helps locate earthquakes.

Earthquake Effects - Ground Shaking Northridge, CA 1994

Earthquake Effects Ground Shaking Northridge, CA 1994

Earthquake Effects - Ground Shaking Loma Prieta, CA 1989 KGO-TV News ABC-7

Earthquake Effects - Ground Shaking Kobe, Japan 1995

Earthquake Effects - Ground Shaking Kobe, Japan 1995

Earthquake Effects - Surface Faulting Landers, CA 1992

Earthquake Effects - Liquefaction Source: National Geophysical Data Center Niigata, Japan 1964

Earthquake Effects - Landslides Source: National Geophysical Data Center Turnnagin Heights, Alaska, 1964

Earthquake Effects - Fires Loma Prieta, CA 1989 KGO-TV News ABC-7

Earthquake Effects - Tsunamis 1957 Aleutian Tsunami Photograph Credit: Henry Helbush. Source: National Geophysical Data Center

Lag Time!

Earthquake Location

Locating an EQ epicenter

Earthquake Magnitude M 5 M 6 M 7