By Ashley Fike
Kern Valley Sun
Kern County was rocked by two large magnitude earthquakes that shook up the Kern River Valley on July 4 and 5.
The first quake occurred southeast of Ridgecrest at just past 10 a.m. on July 4 with a magnitude of 6.4, the largest that Kern County had experienced in 20 years; the 7.1 magnitude Hector Mine earthquake was the last large quake in the region in 1999.
The following evening and just past 8 p.m., a 7.1 magnitude earthquake struck the China Lake Naval Air Weapons Station, leaving the previous day’s quake labeled a ‘foreshock’ and the July 5 quake the ‘mainshock.’
The Kern County Sheriff’s Office assisted other agencies, fielding 911 calls for Ridgecrest Police Department and assisting them with service calls, as well as sending air support to scan for significant damage.
Ridgecrest Regional Hospital (RRH) reported finding cracks in walls, broken water pipes and water damage after the foreshock and discovered that the new patient tower would require repair work on its second floor after the mainshock. RRH President/CEO James Suver confirmed that repairs were likely to take several months.
RRH patients were evacuated to hospitals in surrounding areas until the hospital fully reopened on Monday, July 8.
“We have seen tremendous support from the community, our business partners, the city, Kern County EMS and the State EMS agency,” said Suver, “and the dedication and commitment from our own employees and volunteers is unparalleled. We cannot begin to thank everyone enough for pulling together in this time of need and getting the hospital back open again for our community.”
The Ridgecrest Police Department also reported fires, downed power lines, mobile homes knocked from their foundations and unsafe structures. Displaced families from Ridgecrest and Trona were directed to temporary shelters and a Local Assistance Center for disaster assistance.
The nearby town of Trona was left without access to clean drinking water, prompting an influx of donations.
Buckled roads outside of Trona and within China Lake NAWS were found and repaired. China Lake reported on July 7 that it was not mission capable and would require that only mission essential personnel attempt to access the base until further notice.
The base opened up limited medical and dental services, as well as limited access to the Navy Exchange, for personnel in the following days.
In the Kern River Valley, the effect was minimal. Local retail stores were subjected to cleanup after the shocks rattled merchandise off their shelves, but major structural damage was not evident.
SR 178 through the Kern River Canyon was closed after the mainshock caused a rockslide that left the road blocked. The canyon was opened again shortly after midnight on July 6.
The U.S. Geological Survey (USGS) reports that while plenty of aftershocks are still expected, the chance of an aftershock of magnitude 5 or higher until July 16 is 50 percent, a magnitude of 6 or higher is 7 percent, and a magnitude of 7 or higher is 1 percent.
The USGS says that these estimates are due to statistical analysis of past earthquakes, and while the probability of aftershocks in a region can be estimated, it is not possible to predict exactly where and when they will occur.
This forecast also changes as aftershocks occur, as larger aftershocks may trigger further earthquakes. While the USGS says that these quakes are possible, their probability is very low.