Two big earthquakes hit southern California last week, renewing fears of the “Big One” that Californians have long been warned about. Fortunately, the earthquakes – magnitude-6.4 on Thursday followed by magnitude-7.1 on Friday — hit a sparsely populated area 18 kilometers from the city of Ridgecrest, but they were enough to damage some buildings, crack roads, and disrupt some water and gas lines in an area from Sacramento City to Mexico in the south.
The two earthquakes were not even on the San Andreas Fault, a major crack beneath the earth that runs along Western California, alongside Los Angeles, and cuts across California’s thickly populated San Bernardino County. In 1994, a magnitude-6.7 earthquake — only a quarter as powerful as the 7.1 second Ridgecrest earthquake — killed 57 people a nd injured over 8,700, because it hit close to LA. Today, the people of LA live in fear of the “Big One” – a magnitude-7.8 earthquake which geologists said is long overdue.
We in the Philippines also have long lived in fear of our own magnitude-7.2 “Big One” which, it is said, could come at any time. We have beneath Bulacan, Metro Manila, Cavite, and Laguna a “West Valley Fault” which caused a major earthquake in 1658 and, it is feared, will snap again after some 400 years and cause a 7.2 earthquake in Metro Manila.
When that happens, a study by the Japan International Cooperation Agency said, the death toll could reach 34,000, with 300,000 injured as many buildings collapse. It is for this reason that we have been holding annual “Shake Drills,” with everyone asked to “Duck, Cover, and Hold” under a table or other solid support and protect one’s head from falling objects.
Most of the world’s earthquakes have occurred on the so-called Pacific Ring of Fire, filled with so many volcanoes and with underground earth masses grinding against each other. This ring goes around the Pacific — from Alaska in the northeast, along the western coasts of North, Central, and South America, to the islands of the South Pacific, the islands of Southeast Asia, to Japan, Kamchatka peninsula, back to Alaska.
Nearly all of the world’s most powerful earthquakes have taken place along this Ring of Fire. The most powerful was a magnitude-9.5 that hit Chile in 19
60, followed by a magnitude-9.2 in Alaska in 1964, a magnitude-9.1 in Sumatra in 2004, and another magnitude-9.1 in Japan in 2011. Hundreds of weaker earthquakes have occurred over the centuries. Only this Monday, a 6.9 earthquake struck off the coast of Indonesia’s Sulawesi island directly south of us.
Following the two Ridgecrest earthquakes last week, the people of California are on alert. We too should continue to be on alert for our own “Big One” by joining the annual exercise and taking all the suggested precautions, such as being ready with emergency food and medical kits.
Tags: Roni Santiago