The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them. Population was estimated as 37 in 2004.

Parkfield, The Earthquake Study Capital of the World

The town of Parkfield, located on the San Andreas Fault in central California and 200 miles from San Francisco, is one of the world’s most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's.

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The Parkfield Earthquake Experiment, led by the United States Geological Survey (USGS) and the State of California, is a long-term earthquake research project on the San Andreas Fault. Its goal is to observe the fault and better understand the physics of earthquakes - what actually happens on the fault and in the surrounding region before, during and after an earthquake.

Ultimately, scientists hope to better understand the earthquake process and, if possible, to provide a scientific basis for earthquake prediction.

The Earth's crust is fractured into a series of "plates" that have been moving very slowly over the Earth's surface for millions of years. Two of these moving plates meet in western California and the boundary between them is the San Andreas Fault. The Pacific Plate (on the west) moves northwestward relative to the North American Plate (on the east), causing earthquakes along the fault.

The San Andreas Fault is approximately 1300 km (800 miles) long. If a person stood on one side of the fault and looked across it, the block on the opposite side would appear to have moved to the right. Surveying shows a drift at the rate of as much as 2 inches per year
Sudden offset that initiates a great earthquake occurs on only one section of the fault at a time. Total offset accumulates through time in an uneven fashion, primarily by movement on a first section of the fault and then on another one. Great earthquakes are produced by sections that remain "locked" and quiet over a hundred or more years while strain builds up then, in great lurches, released.
During the 1906 earthquake in the San Francisco region, roads, fences, and rows of trees and bushes that crossed the fault were offset several meters or yards. Earthquakes are the most costly natural hazard faced by the United States.

The town of Parkfield, population 37, was chosen for the experiment for several reasons. Moderate earthquakes (magnitude about 6) have occurred on the Parkfield section of the San Andreas Fault at fairly regular intervals- one approximately every 22 years, except for the last one in 2004. All these Parkfield earthquakes have struck in the same area and historical seismograms show that at least the 1934 and 1966 shocks initiated at the same point on the fault. These observations suggest that there may be some predictability in the occurrence of earthquakes.

Building on more than 15 years of experience from the Parkfield Earthquake Experiment, the National Science Foundation (NSF) and the USGS started in June 2004 to drill a deep hole in order to install instruments directly within the San Andreas Fault Zone near the initiation point of previous magnitude 6. They reached the fault’s active zone, 2 miles deep, early August 2005.

These instruments, set 2 to 3 kms beneath the Earth's surface, will form a San Andreas Fault Observatory at Depth (SAFOD). This project is part of the global EarthScope Project and will directly reveal, for the first time, the physical and chemical processes controlling earthquake generation within a seismically active fault. As Dr Mark Zobak, one of SAFOD’s principal investigators, told the BBC: ”It’s like using a stethoscope and listening very, very carefully”.

Fault-zone rocks and fluids will be retrieved for laboratory analyses, and geophysical measurements will be made within the active fault zone. SAFOD's long-term monitoring activities will include detailed seismological observations of small to moderate earthquakes and continuous measurements of rock deformation and other parameters during the earthquake cycle.
SAFOD will provide direct information on the composition and mechanical properties of rocks in the fault zone, the nature of stresses responsible for earthquakes, the role of fluids in controlling faulting and earthquake recurrence, and the physics of earthquake initiation and rupture. By observing quakes "up close," SAFOD will mark a major advance in the pursuit of a rigorous scientific basis for assessing earthquake hazards and predicting earthquakes.

Sources and Resources: United States Geological Survey (USGS), EarthScope, SAFOD
USGS’s website: http://www.usgs.gov
Safod’s website: http://earthscope.org/safod/
Parkfield Experiment http://quake.wr.usgs.gov/research/parkfield

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Sections of cuttings sampled from the SAFOD drilling hole in Parkfield, CA, and examined by Research Geologist Diane Moore. The identification of the grains allows her to estimate the location of the drill. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
Title:
Parkfield, The Earthquake...
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July 13, 2005
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Sean Mitchell, mud loggger for Pason Systems, examines ground up rock chips, or cuttings, rock cuttings samples collected from the drilling mud from the San Andreas Fault by the SAFOD drill in Parkfield, CA.  The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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July 13, 2005
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Geologist Andy Snider  inside the telemetry hub on top of a hill in Parkfield, CA, that houses instruments and computers collecting earthquake data from a network of seismic and GPS measurement devices. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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July 14, 2005
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German chemist Thomas Wiersberg collects for analysis the gas extracted during the drilling into the San Andreas Fault in Parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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Raphael Almeida, a geology student helper, divides in equal parts samples of dry cuttings sampled from the SAFOD drilling hole in Parkfield, CA. These samples are collected during drilling at regular intervals for identification to assist in technical drilling decisions and for later study by the scientific community. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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Parkfield, The Earthquake...
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July 13, 2005
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Alan Bartley, a Fluids Engineer, analyses and adjusts the drilling fluids used in drilling into the San Andreas Fault by the SAFOD drill in Parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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July 13, 2005
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Scientists at work inside the main trailer of the SAFOD project in Parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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July 14, 2005
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Geophysicist and co-principal investigator of the SAFOD project., Mark Zoback, at the SAFOD camp in parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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Parkfield, The Earthquake...
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July 15, 2005
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Geophysicist and co-principal investigator of the SAFOD project., Steve Hickman,  in front of the drilling rig in Parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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The San Andreas Fault viewed from the side of the North American plate in Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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View of the San Andreas Fault at the Wallace Creek near Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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July 15, 2005
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A telemetry hub on top of a hill in Parkfield, CA, that houses instruments and computers collecting earthquake data from a network of seismic and GPS measurement devices. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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One of the GPS antenna placed on top of a hill in Parkfield, CA, that detects ground movements as small as 2 to 3 mm. The antenna feeds a vast network of seismic and GPS earthquake measurement devices. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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July 14, 2005
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View of teh valley where lies the town of Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 15, 2005
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View of Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Jeff Hordwell stands by his wall that fell during the last major earthquake in Parkfield, CA. The earthquake was of magnitude 6 and happened on September 28, 2004. Hordwell, a rancher, moved to Parkfield 8 years ago from Leona Valley, another town located on the San Andreas Fault in California. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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40-2276-1241
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A chimney that was badly damaged during the last major earthquake in Parkfield, CA. The earthquake was of magnitude 6 and happened on September 28, 2004. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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Jack Varian, owner of the V6 ranch in Parkfield, CA, surveys his cattle. When asked about earthquakes, Varian says that it is no such a big deal for the people of Parkfield as real damage rarely occurs. "A drought is more devastating" he says. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
Title:
Parkfield, The Earthquake...
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July 15, 2005
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42-2276-1867
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The only cafe and restaurant in Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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The water tank of the only cafe and restaurant in Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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Inside the only cafe and restaurant in Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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The menu of the only cafe and restaurant in Parkfield, CA. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas. Its inhabitants like to call it the "Earthquake Capital of the World". It has been the site of an intensive earthquake study since the late 1970's and a team of scientists recently reached the fault's active zone through a 2-mile deep borehole. This project, named SAFOD, is a major step in learning more about earthquakes and maybe predicting them.
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Parkfield, The Earthquake...
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July 14, 2005
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Geophysicists and principal investigators of the SAFOD project, Mark Zoback and Steve Hickman, discuss the latest developments of the drilling into the San Andreas Fault  in Parkfield, CA. The San Andreas Fault Observatory at Depth (SAFOD) is a deep 2-mile (3.2km) (3.2 km) borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's
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Parkfield, The Earthquake...
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July 13, 2005
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Aerial view of the region of the San Andreas Fault Observatory at Depth (SAFOD) drilling rig in Parkfield, CA. The SAFOD is a deep 2-mile borehole observatory that has reached, for the first time, the fault's active zone early August 2005. The SAFOD will directly measure the physical conditions under which plate boundary earthquakes occur. It is a major step in learning more about earthquakes and maybe predicting them. The town of Parkfield, located on the San Andreas Fault in central California, is one of the world's most seismically active areas and has been the site of an intensive earthquake study since the late 1970's. Courtesy of EarthScope.
Title:
Parkfield, The Earthquake...
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July 22, 2005
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