Earthquakes 101 (EQ101)

Lisa Wald and Penelope NicholsUSGS Pasadena Madrona K-8

U.S. Department of the InteriorU.S. Geological Survey

USGS Earthquake Hazards Program

Earthquakes 101 (EQ101)

Global Distribution of Earthquakes

Lisa WaldUSGS Pasadena

U.S. Department of the InteriorU.S. Geological Survey

USGS Earthquake Hazards Program

Plate Tectonics

Plate Boundaries

Three Types of Faults

Strike-SlipThrust

Normal

Strike-slip Fault Example

Normal Fault Example

Dixie Valley-Fairview Peaks, Nevada earthquakeDecember 16, 1954

Strike-slip Fault Example

1906 San Francisco Earthquake

Thrust Fault Example

The San Andreas Fault

Thrust Fault Example

Total Slip in the M7.3 Landers EarthquakeTotal Slip in the M7.3 Landers Earthquake

Rupture on a Fault

Depth

Into the

earth

Surface of the earth

Distance along the fault plane 100 km (60 miles)

Slip on an earthquake faultSlip on an earthquake fault

START

Slip on an earthquake faultSecond 2.0


What Controls the Level of Shaking?What Controls the Level of Shaking?

• Magnitude–More energy released

• Distance–Shaking decays with distance

• Local soils–amplify the shaking

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

If the earth is shaking as a result of plate movement, volcanic activity, or an

explosion…

…Make predictions about what could happen before viewing the next slides

Earthquake Effects - Ground Shaking

Northridge, CA 1994

Earthquake Effects -Ground Shaking

Northridge, CA 1994


KGO-TV News ABC-7

Loma Prieta, CA 1989


Kobe, Japan 1995

Earthquake Effects - Surface Faulting

Landers, CA 1992

Earthquake Effects - Liquefaction

Source: National Geophysical Data Center

Niigata, Japan 1964

Earthquake Effects - Landslides

Turn again Heights, Alaska,1964 (upper left inset);Santa Cruz Mtns, California , 1989

Source: National Geophysical Data Center

Earthquake Effects - Fires

KGO-TV News ABC-7

Loma Prieta, CA 1989

Earthquake Effects - Tsunamis

Photograph Credit: Henry Helbush. Source: National Geophysical Data Center

1957 Aleutian Tsunami

Seismic Waves

Earthquake Magnitude

M5

M6

M7

We can make predictions about WHERE earthquakes might occur

BUT WE CAN’T YET PREDICT WHEN!

Earthquake Location

Pacific-North American Plate Boundary

Think about what you can change in your room, home, school to:

1) Lessen the harm of an earthquake

2) Deal with the aftermath of an earthquake.

What do we do in case of an

earthquake?

Check this out…and work with your family to create a Disaster Kit and Plan

READY.GOV

Think smart: Think ahead.

Take action.

Earthquakes 101 (EQ101)

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