Men clear away wreckage following the 1906 San Francisco earthquake, which struck California on April 18. (Credit: Arnold Genthe/Library of Congress)
What will happen when the next big earthquake hits northern California? A team of researchers including 抖阴旅行射 Boulder听Professor Keith Porter explored that question at an event April 18 marking the anniversary of the 1906 temblor that leveled much of San Francisco.
A modern earthquake could kill 800 people and cause more than $100 billion in economic losses from the shaking and subsequent fires, according to estimates come from the HayWired Scenario, a project spearheaded by the U.S. Geological Survey (USGS), which is organizing the听event on the campus of the University of California, Berkeley. The exercise looked at the potential outcomes of a magnitude 7.0 earthquake on California鈥檚 Hayward Fault in the east San Francisco Bay Area.
Keith Porter and his colleagues will announce their findings at a public event 4:30鈥�6:30 p.m. Wednesday, April 18,听in Berkeley, California.
Porter, a professor in 抖阴旅行射 Boulder鈥檚 Department of Civil, Environmental and Architectural Engineering, said that the toll of such a disaster could be huge鈥攐n par with the impact of Hurricane Katrina on the southeastern United States in 2005.听
鈥淚t鈥檚 fairly likely that a person living in the Bay Area today will live to see a major Bay Area earthquake,鈥� Porter said. 鈥淭he HayWired scenario reveals weak points in our designs for new buildings, our existing water infrastructure, not to mention problems with fires after earthquakes and with older elevators.鈥滳alifornia hasn鈥檛 seen a major tremor since the rise of the Internet age鈥攖he last was 1994鈥檚 Northridge earthquake in the Los Angeles area. The Hayward Fault itself last ruptured 150 years ago. Scientists estimate, however, that it or another Bay Area fault will likely produce a large earthquake in the next 30 years. The HayWired scenario seeks to help the region learn from the lessons of this when-not-if event without having to experience the costs.
鈥淲e tend to improve our building codes and other aspects of our infrastructure after a big disaster,鈥� Porter said. 鈥淲e learn our lessons the hard way. But what the USGS鈥檚 Science Application for Risk Reduction program has found is that simulated disasters can teach us the same lessons.鈥�
To drill down on those lessons, the project team drew from a wide range of information, including diverse computer simulations, industry data and surveys of California residents. The researchers will release their findings in three volumes. The first and USGS recently published the .听抖阴旅行射 Boulder is a coalition partner on the project. Porter coordinated the engineering analyses for this report and performed many of them himself.
Porter鈥檚 expertise hones in on the long-lasting consequences for buildings and other infrastructure. He said that while California has adopted a stringent building code, these rules focus on getting people out of buildings alive, not necessarily on making them safe for people to go back into.
Under the current building code, an earthquake like the HayWired disaster could render one-quarter of buildings in the Bay Area unsafe for people to re-enter or otherwise limit their usability, he said. The earthquake could spark 450 large fires and cause 4,300 pipe breaks and leaks in the East Bay Municipal Utility District.听
The Hayward Fault runs down the center of the east San Francisco Bay Area and directly underneath the University of California, Berkeley's听California Memorial Stadium (circle at center). (Credit: Detweiler et al. 2017)
But, Porter added, that there鈥檚 another impact of earthquakes that often gets ignored. Drawing on data from the elevator industry, Porter estimates that the hypothetical disaster could strand roughly 20,000 people in elevators across northern California.
鈥淭hat鈥檚 a big deal because electricity might not come back on in parts of the Bay Area for days or more after an earthquake,鈥� Porter said. 鈥淚magine 20,000 people trapped in a metal box for days. That鈥檚 pretty scary.鈥�
Still, Porter said that many of the scary numbers that he and his colleagues reported could be addressed with relatively small investments. For a 1 percent increase in construction costs, for example, new buildings could be made 50 percent stronger.
鈥淏ig earthquakes are inevitable in California,鈥� Porter said. 鈥淭here will be some very serious losses in that kind of earthquake, but some of those losses can be avoided by thinking prudently in advance.鈥�
Porter鈥檚 comments are timely as the California State Legislature is currently considering . This bill would establish a commission that would evaluate making the state鈥檚 building code even tougher, potentially ensuring the survival of more buildings after a natural disaster.
