SCEC VDO Mini Grand

Challenge 2014 Visualizing Earthquake

Country

THE GREAT CALIFORNIA

SHAKEOUTSheila Bart, Greg Berger, Georgina Campos, Garland Chen, Jaquelyn Felix, Brandon Green

WHY IS CALIFORNIA REFERRED TO AS

“EARTHQUAKE COUNTRY”?

The frequency of earthquakes in California

- On average, there are approximately 30 earthquakes each day in California.

- Earthquakes of magnitude 6.0 and greater occur approximately every 5 years.

- In comparison to the central and eastern sections of the United States, California experiences a greater amount of seismicity.

Fault systems throughout California

- The San Andreas Fault system extends from northern California and continues south past the California border and into Mexico.

- In addition to the San Andreas Fault system, there are a number of other smaller fault systems throughout the state of California.

- The Los Angeles area itself has a number of faults that contribute to both small and relatively large earthquakes.

Works Cited

❏<earthquake.usgs.gov/earthquakes/states/seismicity>

❏Jones, L., Benthien, M. “Putting down roots in earthquake country”. Southern California Earthquake Center. 2011. <www.earthquakecountry.info/roots/contents.html>

❏Southern California Earthquake Data Center <www.data.scec.org/index.html>

WHAT TYPE OF FAULTS EXIST IN CALIFORNIA?

The answer may surprise you…

Normal Faults

What is it? Where is it?

◻Caused by extension◻Outward displacement

◻Death Valley⬜Horst and Graben⬜Elevation: -282 ft

Reverse Faults

What is it? Where is it?

◻Caused by compression◻Inward displacement

◻Transverse Ranges

Strike-Slip Faults

What is it? Where is it?

◻Displacement is parallel to fault strike

◻San Andreas Fault

Oblique Faults

◻A combination of strike-slip and reverse thrusting◻The most common type of fault

What is it?

Works Cited◻ Bartolomeo, Eleanor, and Nicole Longinotti. "Tectonic history of the Transverse

Ranges: Rotation and deformation on the plate boundary." . UC Davis, n.d. Web. 19 June 2014.

◻ Johnson, Jenda. "What are the 4 basic classes of faults?" Incorporated Research Institutions for Seismology. Web. 17 June 2014. http://www.iris.edu/hq/programs/education_and_outreach/animations/2.

◻ Jordan, Tom, Raymon Siever, and John Grotzinger. "Folds, Faults, and Other Records of Rock Deformation." Understanding Earth. New York: Frank Press, 2003. Print.

◻ "Lowest Places on Earth." Death Valley. National Park Service. Web. 17 June 2014.◻ "The San Andreas Fault." USGS. 17 January 2013. Web. 17 June 2014.

http://pubs.usgs.gov/gip/earthq3/safaultgip.html.

PLATE BOUNDARIES IN CALIFORNIA

Plate Composition

7 km (4 mi) thick Basalt More dense

Varies between 10 and 75 km (6 and 47mi)

Granitic rock Less dense

Oceanic Continental

Plate Boundaries

Two plates move apart in opposite directions

Think: conveyor belts Magma flows up from

the mantle where plates thin

Mid-ocean ridges

DivergentConvergent Plates pushing into

each other Continental →

Continental Continental → Oceanic Oceanic → Oceanic DENSITY Mountain formation Subduction

What kind of plate boundaries are found in California?

San Andreas fault zone → Transform Boundary

Pacific plate moves Northwest in relation to NA plate

Great 1906 earthquake that destroyed San Francisco

Transform Horizontal motion past each

other Mostly slide without creating

or destroying material Large earthquakes can occur

at transform plate boundaries

Works Cited Press, F., Siever, R., Grotzinger, J., Jordan,

T. H., 2003, Understanding Earth “Understanding Plate Motions.” United

States Geological Survey: http://pubs.usgs.gov/gip/ dynamic/ understanding.html, May 2012.

Explain how focal mechanisms

can be determined from earthquake data?

What are focal mechanisms?

What are focal mechanisms?

How are they calculated?

What does this all mean?Faulting geometry identification Look they’re beach balls!

compression vs. dilatation

Works CitedCronin, Vince, 2004, A Draft Pimer on Focal Mechanism Solution for Geologists, p. 1-14 USGS, 1996. “Focal Mechanisms.” Learn: Earthquake topics for Education. <http://earthquake.usgs.gov/learn/topics/beachball.php>.IRIS, 2012. “Focal Mechanisms Explained.” <http://www.youtube.com/watch?v=MomVOkyDdLo>. Merriam-Webster, 2014. “the Dictionary.”<http://www.merriam-webster.com/dictionary/dilatation> California Institute of Technology, 2014. “San Jacinto Fault Zone.” <http://www.data.scec.org/significant/sanjacinto.html> Springer Link, 2011. “Earthquake, Focal Mechanism.”<http://link.springer.com/referenceworkentry/10.1007%2F978-90-481-8702-7_158/fulltext.html>  openSHA, 1980. “Strike, Dip, and Rake (focal Mechanism).” <http://www.opensha.org/glossary-strikeDipRake> Calvin College. “Eachquakes: A World in Motion. Recent Quakes, Calvin Seismograph…”<http://www.calvin.edu/academic/geology/seismology/>

ON WHICH FAULTS HAVE MAJOR EARTHQUAKES OCCURRED SINCE THE 1906 SAN FRANCISCO EARTHQUAKE?

What is a Major Earthquake?

Magnitude Intensity

Richter Magnitude

Moment Magnitude

measures the energy released at the source of the earthquake and it is determined from measurements on seismographs.

takes the amplitude and distances of seismograms and is known to underestimate the size of large quakes.

measures the strength of shaking produced by the earthquake at a certain location and it is evaluated from effects on people, human structures, and the natural environment.

Magnitude is related to the physical parameters that uses seismic moment (Mo), the force needed to generate the recorded waves, determines the energy released by the quake. MW = 2/3 log10(MO) - 10.7

What is a Major Earthquake?

San Francisco Earthquake 1906

5:12 AM - April 18, 1906Magnitude: 7.8Intensity: maximum intensity of XI was based on geologic effects, but the highest intensity based on damage was IX.

• Rupturing about 430 km or more to the northernmost of the San Andreas Fault

• The earthquake was felt from southern Oregon to south of Los Angeles and inland as far as central Nevada.

• Due to water pipe breakage, the water was shut off. Since there was no water, the fire got set off causing a large part of San Francisco to burn down.

Major Earthquakes since 1906

Date Earthquake Magnitude Faults 18 April 1906

San Francisco

ML 7.8 San Andreas

4 Nov. 1927

Offshore Lompoc

ML 7.1 Hosgri

21 July 1952

Kern County Mw 7.5 White Wolf

28 June 1992

Landers Mw 7.3 Johnson Valley,

Kickapoo, Homestead Valley, Emerson, and Camp

Rock 18 Oct. 1999

Hector Mine Mw 7.1 Hector Mine (Lavic

Lake) and Bullion

(Pisgah)

Faults Involved . . . Type of Fault Earthquak

e Fault Names

Right-Lateral Strike Slip

Landers

Johnson Valley, Landers,

Homestead Valley,

Emerson, and Camp Rock

faults

Hector Mine

Lavic Lake and Bullion

Reverse with some Left-Lateral

Kern County White Wolf

Reverse and Thrust Lompoc

Hosgri

Works Cited“Historical Earthquakes: San Francisco 1906.” USGS: Earthquake Hazards Program. 1 November 2012. Web.

16 June 2014. <http://earthquake.usgs.gov/earthquakes/states/events/1906_04_18.php>.

“Hector Mine Earthquake.” Southern California Earthquake Data Center. Caltech, 31 January 2013. Web.

16 June 2014. <http://www.data.scec.org/significant/hectormine1999.html>.

“Kern County Earthquake.” Southern California Earthquake Data Center. Caltech, 31 January 2013. Web.

16 June 2014. <http://www.data.scec.org/significant/kern1952.html>.

“Lompoc Earthquake.” Southern California Earthquake Data Center. Caltech, 31 January 2013. Web. 16 June 2014. <http://www.data.scec.org/significant/lompoc1927.html>. “Landers Earthquake.” Southern California Earthquake Data Center. Caltech, 31 January 2013. Web.

16 June 2014. <http://www.data.scec.org/significant/landers1992.html>.

“Measuring the Size of an Earthquake.” USGS: Earthquake Hazards Program. 1 November 2012. Web.

16 June 2014. <http://earthquake.usgs.gov/learn/topics/measure.php>.

Zoback, Mary Lou. “The 1906 Earthquake and a Century of Progress in Understanding Earthquakes and

their Hazards.” GSA Today April/May. 2006: 1-11. Print.

What is “Drop, Cover and

Hold on” and who is

participating?

ShakeOut: “Drop, Cover, and Hold On.”

11 million participants (US & other countries) 7,200,000 from California 830,000 from Japan

Who is Participating? K-12 School Districts Colleges and Universities Businesses Government Institutions

What is “Drop, Cover, and Hold on?”

Actions to take during an earthquake: DROP to the ground COVER by getting under a sturdy desk or

table HOLD ON to it until the shaking stops

Works Cited Shakeout – Drop, Cover, and Hold On:

http://www.shakeout.org/dropcoverholdon/