More than 18 earthquakes hit the central San Andreas fault early this week, and scientists at the US Geological Survey are taking note. The quakes have registered up to 4.2 on the richter scale, and are centered in the Hollister and Gilroy area.
These clusters of earthquakes over a short period of time are called swarms. Earthquake swarms have been reported in the lead up to major earthquakes in the past, but there is no way to know if a swarm is signifying major movement to come, or is simply a fault releasing pressure.
The Mighty San Andreas
The San Andreas fault stretches from north of San Francisco all way southeast of Los Angeles, and has tens of millions of people living nearby. The last major rupture was the 1989 Loma Prieta earthquake that rocked San Francisco and the Bay Area, which caused 57 deaths, 3,757 injuries, $6 billion in damage and power outage for 1.4 million people.
While seismologists are quick to point out that an earthquake swarm like this doesn’t necessarily mean a lead up to larger quakes in the short term, they continue to encourage people living near the San Andreas to have a plan in place and the essentials for the aftermath of an earthquake. We do know that the San Andreas will continue to produce major earthquakes, and that it is overdue for another large quake. By planning to be an earthquake survivor with or without emergency responders assistance, our entire community will be safer.
What do Experts Recommend?
Make sure you and your family have a plan. Know where you'll meet after an earthquake. Plan and practice an evacuation route from your home. Designate an out-of-town contact that everyone can connect with, as phone service may be down. Write down and keep copies of the emergency contacts for your area, and your out-of-town contact.
Most importantly, if you don't have an Earthquake Bag and a plan in place get it done today. You need to have food and water for at least a few days, communication and light sources that don't rely on the electric grid (like a hand-crank radio/flashlight/phone-charger), shelter and warmth, first aid, hygiene, and tools and equipment needed in the aftermath of an earthquake. If your house or building has gas lines, get a gas shutoff tool and ziptie it to the turn-off valve.
Scientists say they’ll continue to monitor the fault closely over the next 1-2 weeks. It is hard to predict how faults will react, but the San Andreas is giving us a reminder to be prepared for the inevitable.