If you look at the USGS earthquake map of the US, it all seems fairly predictable. The West Coast has earthquakes, - mostly in California. The rest of the country - not so much. Until recently. The 5.8 East Coast earthquake last August left people unharmed but "rattled". Last month, Oklahoma of all places, had a slew of earthquakes, including one that was 5.6.
Sparks, Oklahoma - Redefining Red State
That particular area of Oklahoma, around where the pipeline is slated to go through, has had over 1000 earthquakes in the past year, but historically had only 50 earthquakes a year. The biggest of the latest series of Oklahoma earthquakes measured 5.6 on the Richter scale. It was pretty scary, as the San Francisco Chronicle, reported: "'WHAM!', said Joe Reneau, 75, gesturing with swipes of his arms. 'I thought in my mind the house would stand, but then again, maybe not.'"
There's speculation that recent fracking activity is causing the spike in earthquakes. The way the media has it, fracking might precipitate earthquakes -- or it might not. IEEE Spectrum weighs in on the issue noting that yes, human activities like fracking and dam-building definitely cause seismic activity along established faultlines. Indeed, the USGS put out a report earlier this year linking fracking in Oklahoma to an increase in smaller temblors. Other experts say that fracking could only cause small earthquakes. A Stanford geologist characterized it: "as if you knocked a gallon of milk off the table".
The spate of activity had Oklahoma residents worried. If you've ever been through a series of earthquakes you understand the skittishness. Reeling from the earthquake and aftershocks, their unease became ripe breeding ground for rumors. One of the rumors said officials knew of another impending earthquake even larger than the 5.6 earthquake, but weren't telling residents. In response, officials held a meeting to quell both the rumors and the fears a couple of weeks ago.
Apparently 400 to 500 people attended the two hour meeting organized by the American Red Cross, and officials presented from the Oklahoma Geological Survey, state Emergency Management Department, Lincoln County emergency management office, state Insurance Department, Salvation Army and other groups. They moved the meeting to a bigger facility to accommodate the huge turnout. They wanted to dispel the rumors. As Newsok.com reported: "There should be no bigger quake coming, said G. Randy Keller, director of the OGS" Officials assured people they most likely wouldn't feel the aftershocks, and that governments were prepared for whatever happened. All things you would expect them to say.
Nothing's Too Different in Oklahoma
Officials thought the Oklahoma audience was perhaps frustrated by the experts inability to explain the spate of the earthquakes, though they were reassured. And that nervousness in Oklahoma is just the same as nervousness anywhere -- except Japan, I guess where they've had hundreds of aftershocks in the 5-7 range since Fukushima, including a 5.9 earthquake today, and they all just seem ho-hum about it.
In San Diego, California, the Juanita Faultline has recently caused a series of small earthquakes, leading SignsOnSanDiego to interview a local geologist about the likelihood of another earthquake. The article, "Should We Worry About Shaking on San Jacinto Fault?" illustrates the difficulty geologists have predicting the next earthquake. Foreshocks and tiny shocks called microseismicity sometimes precede earthquakes, but often they don't. The geologist spent most of the interview, citing the history of earthquakes along known faultlines to answer questions about the "next earthquake".
In Berkeley, California last month, a series of earthquakes along the Hayward fault led to similar nervousness in the Bay Area about the possibility of a larger temblor. Speculation abounded, and again geologists worked to get the facts out based on what they know about "hazard probabilities" along Califonia faults. Small earthquakes don't relieve stress they said. Mathematically, they noted, there's a very small chance that on any given day after a series of small earthquakes.
This all seems slightly analogous to a doctor predicting your likelihood of getting a particular disease by looking at your family's medical history. They can tell you that you too, are at risk of a heart attack. The insurance company might be more precise. And along some faultlines, geologists know the history and other details enough to say in the next 30 years, the probability of and earthquake larger then 6.5, say, is 65%.
And in L'Aquila?
Now a good part of the US knows what a temblor feels like, and many people have been told by experts to not worry. We can then imagine how the situation erupted after scientists reassured citizens of L'Aquila in March, 2009, that an earthquake was unlikely. In addition to the earthquakes, Italian citizens were subjected to the prognostications of a fellow citizen with no scientific knowledge who busied himself making dire predictions prior to the earthquake (similar to the earthquake soothsayer we recently blogged about, featured on FOX News.)
The next week, a 6.3 earthquake killed 309 people. A group calling themselves "309 martyrs" sued seven scientists. They accused the scientists of not providing enough evidence about both the hazardous buildings and risks of an earthquake. The town is also suing for about $68m in damages.
In Oklahoma and L'Aquila, multiple officials met with hundreds of people and the press. The press later noted cheerfully that scientists "calmed" peoples fears and "reassured" them. Through all that communication, it's clear that there might be a possibility for misinterpretation?
The trial has been delayed multiple times and according to people who know the Italian court system, will most likely drag on for years. The episode chills earthquake scientists, who constantly grapple with how to relay risks in ways that people understand without freaking them out. It's a science in progress.