‘The earthquake is inevitable, but the disaster is not’ Lessons for California from Taiwan temblor

A powerful rush-hour earthquake that shook Taiwan, one of the world’s best-prepared places for earthquakes, on Wednesday morning could provide crucial lessons for Southern California.

The quake, measured at magnitude 7.4 by the U.S. Geological Survey, killed at least nine people and injured hundreds on the island, which is about one and a half times the size of Vermont.

Like California, Taiwan is no stranger to powerful and devastating earthquakes. Factors that likely reduced the damage inflicted by Wednesday’s earthquake, the strongest on the island in 25 years, were the location of the fault, strict building codes and a collective effort to prepare for natural disasters, say the experts.

“If this earthquake happened in Taipei, the damage would be much greater. If you cause this earthquake in Los Angeles, the damage will be much greater,” said Lucy Jones, seismologist and founder of the Dr. Lucy Jones Center for Science and Society. “Simply recognizing that the fault did not come close to a major population center is probably the most important factor.”

Hualien County, a sleepy tourist area in eastern Taiwan about 100 miles (160 km) from Taipei, the island’s capital, was close to the epicenter and was hardest hit. The first floors of several buildings in the city collapsed, leaving multi-story towers tilted on their sides. Authorities worked to free more than 100 people trapped in the rubble.

Buildings on the eastern part of the island – home to most of the Formosan natives, who make up about 2% of the island’s population – are older than those in more urban areas. According to experts, the buildings that collapsed were probably not renovated.

The last major earthquake in Taiwan was in 1999, when a magnitude 7.6 quake struck about 90 miles southwest of Taipei, killing nearly 2,500 people. Authorities subsequently reassessed and tightened building standards.

In Los Angeles, structural engineers have long warned of the risk of concrete buildings collapsing during a major earthquake, as happened in the 1971 Sylmar and 1994 Northridge quakes.

Yet many older buildings in California have not yet been updated to the latest standards, leaving them vulnerable to damage or collapse during a major earthquake. Depending on the type of building, retrofit solutions include adding support elements such as steel frames or beams, installing new concrete walls, or repairing vulnerable welds.

“It is important to pay attention to the fact that there are still buildings that have not been renovated,” said Patti Harburg-Petrich, structural engineer. “One thing we can take away as a community from this earthquake is the importance of investing in these safety measures so that we can make sure that when the Big One hits California, we can keep everyone safe the world.”

The Inland Empire is home to dozens of older brick buildings that have not been renovated. In Los Angeles, about 6,000 buildings have been identified as potentially needing renovation, according to information obtained by The Times this year.

Los Angeles, Torrance, Pasadena, Santa Monica, Culver City, West Hollywood and Beverly Hills have all recently passed laws requiring certain vulnerable buildings to be renovated.

“Earthquake is inevitable, but disaster is not,” Jones said. “We absolutely know how to build communities that don’t fall apart. We simply chose not to do it.

Another striking similarity between Los Angeles and the part of Taiwan that suffered strong shaking in the earthquake is the condition of the soil. The Los Angeles Basin, like Taipei, is essentially “a big bowl of loose sediment” that can amplify movements, Jones said.

When the ground began to rumble in Taipei on Wednesday morning, a SET News anchor stood in front of a camera in the middle of a broadcast. She tried to maintain her balance as the room swayed. Small pieces of fabric were falling from the ceiling.

“I can’t even stand and maintain my balance, especially with the ceiling shaking and many objects falling. I want to remind all viewers to take care of themselves and be safe amid the earthquake,” she said in Chinese.

Lev Nachman, who has lived in Taiwan on and off since 2012, has become accustomed to the occasional tremors. Taiwan is particularly vulnerable to earthquakes due to its position in the most seismically active zone in the world, known as the Ring of Fire.

The 31-year-old was startled awake in his room in Taipei shortly before 8 a.m. by the sound of his phone ringing with a notification from the island’s automated earthquake warning system. The text message arrived about 30 seconds before the shaking began.

“It was like a Disney ride I didn’t sign up for,” he said. “A typical earthquake is a bit like you’re in a chair and someone is shaking you back and forth. It was like two people playing tug of war with you on a chair.

Some residents have expressed concerns about the alert system because not everyone has been informed. Like California, earthquake early warnings are only sent to people living in areas likely to be hit by strong shaking.

But experts say the notification system is an example of how well the technology works.

Limiting the scope of early warnings prevents people from overreacting in areas with lower risk of damage. Taiwan’s system sends a post-earthquake report to all network users, informing people where the quake occurred and how strong it was, said Lingsen Meng, a geologist at UCLA.

This follow-up report serves both “to educate the public and provide them with a sense of reassurance,” Meng said. “That’s something we might be able to learn here.”

Taiwan also benefits from a dense network of seismic sensors throughout the island. While California has a robust seismometer network in the highly populated Bay Area and Southland, coverage in the Mojave Desert and Sierra Nevada is lacking, he said.

“We might want to (find) a way to use community infrastructure to host cheaper sensors, to have better coverage for earthquake alerts in California,” he said. More sensors in these areas would mean less lag time between the rupture and its detection.

The quake also triggered landslides in Hualien, a phenomenon Southern California is likely to experience during a large earthquake along the Sierra Madre or San Andreas faults, Jones said.

Seismologists have long urged Californians to prepare for the “Big One,” defined as an earthquake of at least magnitude 7.8 — 2.5 times larger than the one that struck Taiwan — along the Southern Tier. of the San Andreas fault, which extends almost the entire length of the earthquake. of State.

The rupture caused by the Taiwan earthquake occurred about 22 miles below the surface, said Susan Hough, a seismologist with the U.S. Geological Survey in Pasadena.

At its deepest point, the San Andreas only extends 10 miles into the ground, meaning the energy has less time to dissipate before bursting to the surface. “On the contrary, one would expect stronger ground motions” with an earthquake of the same magnitude as Taiwan’s, Hough said.

The most important lesson California can learn from earthquakes elsewhere is that they are inevitable, Hough said.

The last earthquake above 7.0 in California was a 7.1 quake in Ridgecrest in 2019. It killed one person and caused $5.3 billion in damage. The only thing that prevented a much higher death toll was the geological luck that it occurred in an area less densely populated than California’s major cities.

“People may start to think that, ‘Well, yes, earthquakes happen, they shake, but they’re not that bad,'” Hough said. “But we’re going to have big earthquakes close to people.”

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