Their 7.1, our 7.2


MEDIUM RARE

By JULLIE Y. DAZA

Jullie Y. Daza Jullie Y. Daza

A few things to learn from the 7.1 magnitude earthquake that shook, rattled and rolled Southern California last Friday (Saturday in Manila), courtesy of one of the world’s most famous seismologists, Dr. Lucy Jones, during a press briefing that was intercut with CNN live reports.

(No, it’s not related to the Big One of 7.2 magnitude that we’re supposed to be bracing and drilling for. That it went all the way to the United States does not mean we’ve been spared, though you’d wish that were so. It didn’t even occur along the vaunted San Andreas fault but “hundreds and hundreds of miles away.”)

At 7.1 it was an aftershock, 11 times stronger than the 6.4 foreshock that struck the day before. (According to our own Dr. Renato Solidum, one magnitude higher means an earthquake is felt 32 times stronger.)

Ridgecrest, population 28,000, did not suffer catastrophic damage even with gas fires because the area has desert-like conditions. Power was cut, people were scared by the shaking and while most of them refused to go back to their houses, some preferred to sleep in their cars, never mind that they “bounced” like balls. The town’s hospitals were not at full service due to the previous day’s quake.

“Thousands of aftershocks were recorded” since the Thursday tremor, and a warning was aired that with the “earthquake sequence ongoing” a stronger quake could not be ruled out, on a “5 percent chance usually within a day.”

“Dynamic and ongoing,” the 7.1 quake was initially placed at 0.9 km deep, when it was actually 10 miles down. Los Angeles, 150 miles from the epicenter, felt the quake at 4.5. There have been much stronger earthquakes, including an 8.9 in Chile.

Seasoned reporters reminded viewers to be prepared with water and gasoline; keep your head safe (even a teacup or a painting falling on your top could be dangerous); the rule is duck, seek cover; ground ruptures could induce gas fires; water mains could break; stay away from power lines.

We know so little about the predictability of earthquakes that what useful bit we can pick up should be taken seriously. It takes something like this – their experience of 7.1 vs our fears of 7.2 – to shake us out of our complacency. ###