Zack Bick Erin Riggs Alicia Helton Cara Dickerson Presentation by:

What is it?  San Andreas Fault, geological fault zone in California  800mi long and approx. 10mi deep  Right lateral strike-slip fault  Imperial Valley to Point Arena  Marks the boundary between N.American and Pacific plates  Movement of the plates cause earthquakes

Surface Features  A linear trough reveals the presence of the fault  The fault zone is marked by distinctive landforms  These include long straight escarpments, narrow ridges, and small un-drained ponds  Stream channels characteristically jog sharply to the right where they cross the fault

Brief History  The San Andreas Fault has been dated at 29 million years old  The greatest recorded movement at one time was 5 meters in the great San Francisco Earthquake of 1906  This measured an 8.25 on the Richter Scale

Major Earthquakes Along the Fault  1906, San Francisco  Began at 5:12 am, lasted seconds and the aftershocks lasted seconds  It measured 8.25 on the Richter Scale

1906 San Francisco Quake  The number of deaths resulting from the quake and the fire following the quake was 3,000  The total number of injuries was 225,000  The property damage that occurred was estimated at $400million in 1906 dollars.

1952 Kern County Quake  Occurred on July 21, at 5 am  The quake measured 7.5 on the Richter Scale  The quake was felt from Reno, Nevada to San Diego, California

1952 Quake  The quake came as a surprise to geologists  The quake was responsible for:  12 deaths  18 injuries  $50 million in property damage

1989 Loma Prieta Quake  Occurred October 17 th, at 5 pm  The magnitude was estimated 7.1 on the Richter Scale  The quake did not come as a surprise to geologists

1989 Quake  The quake caused damage in San Francisco and Oakland  The 1989 earthquake caused:  $7 billion in damage  12,000 displaced people  3,757 injuries and 67 deaths

New Designs and Construction of Buildings in Earthquake Prone Areas  Buildings, homes, bridges and overpasses will be built to withstand strong shaking  Some cities have programs to tear down unstable buildings or homes  Automatic shut off of gas lines when the P-wave hits to limit fire hazards

 Places not to build homes or buildings:  Ground failure areas of liquefaction  Landslide prone areas Selective Use of Land

Accurate Prediction of Earthquakes (A Work In Progress)  China has been the only country who has predicted an earthquake nine hours before, in which they saved lives  However, the next quake they had came unexpected  In Tokyo, Japan they are hard away at work trying to learn how to successfully predict earthquakes  Other geologists around the world are also working to find an answer to predict the quakes

Earthquake Probability  Research conducted since the 1989 quake helped USGS and other scientists conclude:  70% probability of at least one magnitude 6.7 or greater quake  21% probability of that 70% is on the San Andreas Fault  The quake might strike the San Francisco Bay region before 2030  Major quakes may occur in any part of this region  Communities in the Bay Area region continue to prepare for earthquakes

Earthquake Odds  Rates of large earthquakes in the San Francisco have dropped after the Great 1906 Earthquake.  San Andreas Fault slipped so much over such a great length in that quake that the strain was reduced on most faults throughout the region.  Strain has been slowly building up again.  However, level of seismic activity has not yet reached that of the late 1800's.

In Conclusion, we’ve learned:  The geography of the San Andreas Fault  A few of the major quakes on the fault  What everyone can do to help reduce the risk of disaster when a quake hits  Probability of the next big earthquake