Ready to rumble in Reno?
Posted: Monday, May 05, 2008 7:30 PM by Alan Boyle
Courtesy of Cal Orey |
Cal Orey says her Brittany spaniels, Simon
and Seth, help her predict seismic events.
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Tiny earthquakes have been swarming near Reno for weeks, and seismic experts are trying to gauge whether things are settling down or heading toward a bigger rumble. All this is making some of the region's residents jittery - including Cal Orey, who lives near Lake Tahoe and issues earthquake predictions based on such things as headaches, pet behavior and moon phases.
Orey made headlines when she called the current wave of shakers in advance - and now she thinks a stronger quake could hit by the end of this month. To be specific, she's predicting a 70 percent chance of a magnitude-5 to magnitude-6 quake in the Reno/Tahoe/Sierra region by the end of May.
"I'm not saying 100 percent," she told me today. "But it's likely."
Seismologists don't tend to put stock in such predictions, as I explained in a report about quake forecasting a couple of years ago. However, the practical effect of what the experts are saying is pretty much the same: Be prepared for a Bigger One.
"We can't predict earthquakes, but we are using the publicity that this sequence of events has generated to try to encourage people to be ready for a large earthquake," said John Anderson, director of the Nevada Seismological Laboratory at the University of Nevada at Reno. "The issue is preparedness."
Anderson said the rumbling in Reno began in late February, just a week after a magnitude-6 earthquake shook buildings in Wells, Nev. (Orey pointed to a report showing that she predicted that one, too.) At first, there were two or three seismic events per day that measured magnitude 1 or greater. But the activity increased in April, climaxing with a shallow magnitude-4.7 shock that rattled Reno's residents.
"After that we had fairly intense activity, which in hindsight looks like an aftershock sequence," Anderson told me today. "Initially, the rates were dropping down pretty fast, but now for the last six days, it looks like the rates have stabilized at 20 per day. We'd like to see them dropping off faster, which would give us confidence that it's an aftershock."
Can science predict quakes?
Experts have been monitoring the situation with a widely distributed network of strong-motion instruments, supplemented by portable sensors from the Incorporated Research Institutions for Seismology. But the sensor readings can't be used to predict with any certainty what might happen.
Marilyn Newton / Gazette-Journal via AP file |
Keith Phillips checks the damage to his house in
Mogul, Nev., a suburb of Reno, on April 26.
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"While the heightened probabilities of an earthquake in the next few days might seem dramatic, the probability never really goes down to zero," Anderson said.
He said that goes for other quake-prone areas as well: "These earthquakes are a good reminder for anybody anyplace in the country to be ready to take the very simple precautions that one can find on a dozen Web sites."
Will there ever be a scientific way to predict damaging quakes? Some alert systems have been set up to provide a limited amount of advance warning that a major shaking is on the way, giving emergency agencies a precious few seconds to protect critical infrastructure. The warning systems, pioneered by Japan, are designed to detect the precursor seismic waves that come before more damaging waves.
"We've thought about that, but for this particular source zone and for downtown Reno, this type of warning is not going to give people much help," Anderson said. At best, there would be a second or less of warning. And there's no scientific way to predict a quake days in advance, he said.
Can people predict quakes?
That doesn't stop "earthquake sensitives" from trading predictions on Web forums such as Earthquake Epi-Center (which Orey co-founded). Some sensitives speculate that they are picking up on magnetic fields that may be precursors of seismic activity - and that they feel the effect of those fields as headaches, nausea or anxiety.
Orey agreed that the idea sounds crazy. "I've had people say how their body hurts before a quake, and I always thought they were wacky," she said.
But now she numbers herself among the sensitives, and often takes cues from her cat Kerouac and her two Brittany spaniels. "I realized that humans can be just like animals, and they can fine-tune these senses," she said.
Orey's mentor in the field is retired geologist Jim Berkland, who looks for links between quakes and the potential effects of the sun and the moon on Earth's tidal flexing. Orey saw a link between the Wells earthquake and February's total lunar eclipse. Now she thinks tonight's new moon as well as the full moon at mid-month may give an extra "nudge" to Reno's seismic activity.
"It's playing out the way I knew it was going to," she told me.
By the way, Reno isn't the only focus of Orey's predictions: She also sees the prospect for seismic activity rising this month to a magnitude of 6 to 7 in Northern California, around Eureka.
The prediction game is a bit like playing the slots in a Nevada casino, in that a few successes can make up for a host of failures: If Orey is wrong, her forecast will be little-noted - but if she's right, it might earn yet another headline. Is Orey going out on a limb, or is she merely playing the percentages? Feel free to weigh in with your comments below.
