By Charly SHELTON

Earthquakes are an ever-present danger in California. Living right along the San Andreas Fault, a quake could hit at any moment without warning, devastating homes, businesses and public areas alike. This is exactly what happened at 4:31 a.m. on Monday, Jan. 17, 1994 – 23 years ago Tuesday.

A 6.7 magnitude earthquake rocked the southland with an epicenter in Reseda but the damage was felt hardest in Northridge, so the quake came to be known as the Northridge Earthquake. The shaking lasted only 10 to 20 seconds, yet the force exerted on the ground was so intense that movement was felt as far away as Las Vegas, Nevada. More force was exerted on the ground, in fact, than has ever been recorded by instruments, with a ground acceleration speed of 16.7 m/s², or 1.8g (for reference, the Seismological Society of America estimates that the peak ground acceleration in the 2010 Haiti earthquake to be approximately 0.5g in certain parts of Canape Vert). In addition, the highest peak ground velocity ever recorded came from this earthquake as well, with ground movement clocked at 4.09 mph. In total, 57 people died, over 5,000 were injured and the property damage was estimated as more than $20 billion.

“We sit on the boundary between the Pacific plate and the North American plate, which are traveling past each other, but there is a bend in the main plate boundary,” said Kate Hutton, seismologist at Caltech, in a previous interview. “So there’s actually compression along the San Gabriel Mountain and Santa Monica Mountain areas.

That compression caused one side of the minor faults to slide up and over the other side, and that sudden motion produced vibrations in the ground that people felt as an earthquake.”

Earthquakes are all about pressure. As the plates of rock float on a magma surface, much like a puck on an air hockey table, they slide around very slowly. These plates, knocking into each other and grinding alongside each other, cause pressure to build up between them at the plate boundaries – the faults. Every so often, the pressure builds up enough and the plates slip causing an earthquake.

Think about it this way: Put your hands together, palm-to-palm. Now push them together really hard. Now slowly pull one hand up and one hand down, keeping the pressure hard together. When your hands move, it’s not a gentle slide, it is a fast jerking motion as the pressure releases, moving your hands. That is the same as an earthquake.

Despite the damage and deaths, something positive did come out of the Northridge Earthquake – better preparedness.

“It allowed us to get funding to expand our seismic network and use a lot of modern technologies as they came along to have a faster response, to get the information out. And that would allow responders [to react] sooner, to know where the damage was, for example,” Hutton said. “It also caused an update in the building codes, at least one. It was an impetus to get funding and collaboration between a lot of different universities to map more faults and determine, statistically speaking, how often they break and come up with a risk map of California.”

Even with the update to the building codes and the increase in funding, there is room to improve. Congressman Adam Schiff has been working for several years to get an additional $16.1 million in federal funding to complete an earthquake early warning system which will give residents a few seconds of notice before a quake hits, depending on their distance from the epicenter. Along with Rep. Schiff, 31 other members of Congress sent a letter in December to urge the White House’s Office of Management and Budget to work with federal agencies to continue supporting the development and operation of the early warning system along the West Coast, called ShakeAlert, in Fiscal Year 2018.

On a smaller scale, residents can quake-proof their own homes to mitigate any damage that will occur during an earthquake. Shelves should be bolted to walls, nothing should be hung over beds and delicate or large picture frames and other wall hangings should be affixed with picture hanging strips or earthquake putty. Once the quake starts, people should get under something sturdy, like a desk or table, away from windows. Doorways are not the best choice, but are better than nothing. Homes should be stocked with an emergency kit including water, food, candles, flashlights, first aid kits and any medication needed regularly.

For more information on how to get earthquake ready, visit bepreparedcalifornia.ca.gov and scan the QR code with this story or visit CVWeekly.com for the “Putting Down Roots in Earthquake Country” pamphlet with extensive information about earthquake preparedness.

  Charly Shelton