Los Angeles, deep in the heart of earthquake country. (Image: Flickr/kla4067)
On November 18th, 1755, the ground beneath Boston, Massachusetts started shaking violently, toppling chimneys, sending glassware flying, and confusing fishermen off the coast. Residents interpreted the 6.0 magnitude earthquake as punishment for moral lassitude, and local churches saw a brief increase in attendance.
The 18th century may seem like ancient history, but to geologists, that’s practically yesterday, and natural hazard preparation experts believe the city should be ready for a repeat performance. “It will happen again,” said Lucy Jones, a seismologist with the U.S. Geological Survey and a longtime advisor to several levels of government, noting that 39 states have a significant risk of earthquakes. And because we tend to calibrate our perceptions of risk based on what we’ve experienced in our own lives, “it’s a particular challenge to deal with things that happen on a really long time frame.”
As a geologist, Jones takes the long view, a standpoint that is not always conducive to definitive policy-making. While the precise timing of an earthquake is not constrainable, the event itself – where a fault will rupture and how strong the shaking will be – is, to some extent. “We know pretty well what fault areas will be active over a 100,000 year time scale,” she said, “and the ones that will be active in your lifetime are a random subset of that 100,000 year picture.”
Jones is particularly well acquainted with the dangers of earthquakes in the Los Angeles region, and she recounts the likely repercussions – which electrical lines, water sources, and roads will be compromised along the San Andreas fault – with stunning specificity. She anticipates that water supply will be the biggest challenge, with 85% of the city’s water coming from outside the region. And while local reservoirs have a capacity of 6-months’ supply, the historically severe drought has reduced water levels far below this benchmark. Besides, Jones estimates that it will take three times this long – about a year and a half – to repair damaged aqueducts.
Jones spoke during a panel discussion in late September at the CityLab summit, a two-day conference in downtown L.A. sponsored by The Atlantic, the Aspen Institute and Bloomberg Philanthropies. She used the example of Californian earthquakes to convey the strengths and weaknesses of the “multi-hazards” approach, which prioritizes planning strategies that would be helpful in a range of calamitous situations. A good evacuation plan, for example, is necessary in a wide range of scenarios, from a terrorism threat to a hurricane or tsunami. She also advocates a longer-term move toward more locally self-sufficient regions: “the best way to cope with losing access to water,” she notes, “is to not need it in the first place.” In this way, a lot of the LA region’s climate change sustainability planning is being cross-listed under earthquake preparation.
One of the greatest challenges for planners like Jones is communicating the nature of the risk to residents. “We don’t do a great job with statistics,” she explains. “People can only imagine and prepare for what they’ve experienced.” This civic and institutional memory explains why San Francisco, traumatized by the 1906 earthquake, has done more than perhaps any other city to gird itself against future events.
Countering this ingrained complacency are the forces of globalization. As Jones sees it, no one in the United States took much notice when tens of thousands died in the 1923 Tokyo earthquake, but the 2010 tsunami that swept through Southeast Asia led to substantial international action in an effort to avoid such tragic results in the future. She and other planners are hoping to leverage this growing awareness in the name of future safety, and while these efforts have high-level support, it’s a low salience if high priority issue. But Jones remains determined to keep cities across the country, from L.A. to Boston, from wishing they had done more. “There’s always something we can do,” she says, “and we just need to decide if we can afford it.”
No comments:
Post a Comment