Tectonic MechanismsEarthquakes

ReadingChapter 8: 241-245Chapter 7: 187-196

Lithospheric Plates

Earthquake Locations

• http://earth.geol.ksu.edu/sgao/g100/plots/0916_global_seismicity.jpg

Transverse Wave

http://astro.uchicago.edu/cara/outreach/se/ysi/1999/intro2.html

http://astro.uchicago.edu/cara/outreach/se/ysi/1999/intro2.html

Earthquake: seismic waves

World Series Earthquake apartment building

Portland 2006 November 5Magnitude 2.6

Time Monday November 6, 2006 at 05:34:35.69 Z (UTC) Sunday November 5, 2006 at 09:34:35.69 PM (PST)

Distance from

3.1 km SW of Portland, OR 28.3 km N of Canby, OR 34.9 km NE of Newberg, OR

Coordinates 45.516 deg N122.648 deg W

Depth 16 kmQuality good (BA)

http://www.ess.washington.edu/SEIS/EQ_Special/WEBDIR_06110605343c/welcome.html

Name of Event File: 06110605343c

Earthquake ReportMagnitude 2.6, SW of Portland, OR Sunday November 5, 2006 at 09:34:35.69 PM (PST)

Portland 2006 November 6 seismograph

http://www.pnsn.org/WEBICORDER/PNSN/MCW_SHZ_UW.2006110600.html

Seattle, WA

• Feb 28, 2001, Nisqually quake rocked the Central Puget Sound region

• 6.2 Richter Magnitude • 6.8 Moment magnitude• Centered 57.5 km south-southwest of

Seattle and 52.4 km deep

http://128.205.131.100:591/archives/Seattle.html

http://www.scec.org/earthquakes/

1906 San Francisco fire

Focus, epicenter, fault

Orange grove offset, So Cal

Before deformation

Strain

Release of strain

After strain released

Summary of elastic rebound

San Andreas Fault System

Seismograph

Seismogram showing seismic waves

P-waves

P-waves

S-waves

S-waves

S-type surface waves

Ocean-type surface waves

Summary of seismic waves

Seismic wave travel time curves

Difference of P and S wave travel time

Mercalli scale

Richter magnitude determined by seismic wave recording on a

seismogram

Earthquake magnitudes and expected worldwide occurrence