LA: Big One is coming, warn quake experts
Published 20/07/2014 | 02:30
Next year residents of Los Angeles are expected to flock to cinemas to watch a blockbuster called San Andreas in which their city is wiped out by an apocalyptic earthquake.
As skyscrapers collapse, thousands die and chaos ensues, many in the audience will be wondering how long before it happens for real.
The southern section of the San Andreas Fault that runs near the city has not had a “mega-quake” of more than 7.5-magnitude since 1680 and it is, according to seismologists, more than a century overdue.
A flurry of lesser earthquakes in recent months has refocused attention on whether America’s second city can withstand the ‘Big One’.
“A big earthquake is inevitable,” Los Angeles’ recently appointed “quake tsar” Dr Lucy Jones, said. “Each earthquake that happens increases the probability. We know a lot about earthquakes, we know it will happen. We know everything but the time.”
Dr Jones (59), a US Geological Survey seismologist known as the ‘Earthquake Lady’, rose to fame 20 years ago following the magnitude 6.7 Northridge earthquake in California, which killed 57 people and caused $20bn (€15bn) in damage.
But Dr Jones is worried. What is particularly keeping her up at night is the number of old concrete buildings that have not been retrofitted, and which could topple, or collapse inwardly into a pancake.
The expensive retrofitting process involves reinforcing buildings, for example with steel braces. According to a recent study by the University of California there are 1,451 such buildings including about 50 hotels, 50 churches, and 25 nursing homes. It has been estimated that 5pc of these, about 75 in total, would collapse in a large earthquake.
And the city faces other issues. “The problem with southern California is we have 23 million people,” said Dr Jones. “Even if we were able to predict an earthquake in LA and evacuate, how many people would be killed on the freeways trying to get out?”
Despite these concerns, an enormous decades-long prediction effort is ongoing. Three hours north of Los Angeles the San Andreas Fault passes through Parkfield, population 18, which has bestowed on itself the title “earthquake capital of the world”. The village is the most closely monitored earthquake zone in the world because of the regularity and consistency of its tremors.
Since the 80s a battery of sensors has been installed, including one drilled a mile and three quarters down into the San Andreas Fault. But scientists are still waiting for a revelation.
“There’s a lot of people scratching their heads and trying to come up with a method (of prediction),” said Tim McCrink, a senior geologist with the California Geological Survey.