by Diana Bulls
Are you planning a weekend trip to Morro Bay, Cayucos or Cambria any time soon? If so, why not plan to spend a little extra time on a short side trip to the tiny community of Parkfield, California: a town with the dubious distinction of being the “earthquake capitol of the world!”
Parkfield is located right smack-dab on the San Andreas Fault: the longest, most active and best known of California’s earthquake faults, and the most closely observed earthquake zone in the world. Since the late 1970s, scientists have been observing the fault at close range before, during and after earthquakes in hopes of coming up with a scientific basis for earthquake prediction. The US Geological Survey (USGS) has dubbed this “The Parkfield Experiment.”
Since 1857 or so, Parkfield has had a history of magnitude 6.0 or greater earthquakes on average of every 22 years (1857, 1881, 1901, 1922, 1934, 1966). The data collected over the years suggests the six earthquakes were “characteristic” in that they all ruptured along the same area on the San Andreas Fault. If this characteristic held true, the USGS predicted that there would be a similar earthquake in Parkfield around 1993. The tiny town was inundated with scientists, the press and the curious, but nothing happened.
The big event finally arrived at 10:15 a.m. (PDT) on September 28, 2004, with a magnitude-6.0 earthquake. By that time, everyone was gone but the locals and the scientists.
In 2004, the USGS began the installation of one of the most comprehensive fault monitoring systems in the world: the San Andreas Fault Observatory at Depth (SAFOD). The goal was to drill a hole nearly 2.5 miles into the earth’s crust, across the San Andreas Fault where there were known to be small repeating earthquakes of magnitude 1.0-2.0. The drilling was completed in 2005 and sensors have been installed to capture and record earthquakes that happen near this area.
Scientists are constantly measuring the strain in the rocks, heat flow, seismicity and geomagnetism around Parkfield. The additional time between earthquakes offered the scientific community an opportunity to add and develop improvements in these measurements, plus a better understanding of the physics of earthquakes. The information gathered at Parkfield might still be used someday to issue predictions for major earthquakes along the San Andreas Fault.
The San Andreas Fault appears near Parkfield as a seasonally dry creek bed of the Little Cholame Creek. The fault marks the divide between the North American Plate and the Pacific Plate. You can clearly see the seismic shift in the bridge outside of Parkfield that straddles the plates and the fault. This is the perfect photo op; pose the kids straddling the middle of the bridge, with one foot on the North American Plate (east side) and one foot on the Pacific Plate (west side). If you stand at the end of the bridge, you can easily see where the piers on either side have shifted out of alignment. Measurements taken after the 2004 earthquake showed that the bridge had bent a total of 8-12 inches. Seismologists say that at this rate of movement, Los Angeles will slip right by San Francisco in 30 million years and Parkfield will be a seaside community.
For now, Parkfield is still located in the southeast corner of Monterey County and can be easily reached by the Cholame Valley Road, just past the Hwy 41/46 junction—just plan an extra 2-3 hours on your next trip to the Central Coast. Mining and homesteading used to be a prosperous activity in this community, but the mines were exhausted below economic recovery levels and the industry moved elsewhere.
Today, it is a small town of about 18 people, most of whom are ranchers and farmers. There is a hotel, the Parkfield Inn, and the Parkfield Café. Every year the town hosts the Parkfield Rodeo on the first weekend in May and an annual bluegrass music festival on Mother’s Day weekend. If you just want a one day outing, make a loop approaching Parkfield from Hwy 41 and Cholame Valley Road, then continuing north of Parkfield on the Parkfield/Coalinga Road to 198, and then on to Coalinga and home.
As far as I know, no one has ever been injured in an earthquake in Parkfield, so this is probably the safest place in California to get up close and personal with the San Andreas Fault. Parkfield’s motto is “Be here when it happens.” I’m thinking that could really be a lot of fun!
Another fun short trip to consider would be taking a party bus road trip to Bakersfield.