Could Southern California Sustain Same Damage As Mexico City If 7.1 Magnitude Quake Hits?
LOS ANGELES (CBSLA.com) — Tuesday's powerful 7.1 magnitude earthquake in Mexico caused death, injuries and serious structural damage. What kind of damage would a quake of the same magnitude cause if it happens in the Los Angeles area?
U.S. Geological Survey seismologist Lucy Jones explained the difference.
"Mexico City is built on a dry lakebed. So there was a lake there. It dried out and left behind the sediments that are very very loose. Here in downtown Los Angeles, we have about a factor of five amplification because of soils, and Mexico City is over a factor of 100. So they have damage from earthquakes 100 miles away," Jones explained.
Why does M7.1 cause so much damage?
— Dr. Lucy Jones (@DrLucyJones) September 19, 2017
2. Soil in Mexico City amplifies shaking by 100x or more. Bad soils are a bad idea...
There were also questions about why the much stronger 8.2 quake off the coast of Oaxaca, Mexico on Sept. 7 didn't cause nearly as much damage or loss of life.
ASmaller quake closer to more people can do more damage. The M7.1 today may be worse than M8.2 on 9/8. Magnitude is NOT the shaking you feel
— Dr. Lucy Jones (@DrLucyJones) September 19, 2017
"This earthquake is smaller, but it's closer to many more people. So where the 8.2 was offshore and at a depth of 40 miles down. This is only 80 miles from Mexico City and about 30 miles down with a lot of people nearby. Proximity makes a big difference," Jones said.
After Monday night's 3.6 magnitude jolt was felt on the Westside, fears led people to wonder if Mexico's latest quake was connected.
"The 3.6 yesterday is a size that happens somewhere in the world many times per hour. The only thing that made it newsworthy that it was under the Westside of L.A. and a lot of people commented on it," the seismologist added.