Laptops could be key to an earthquake early-warning system
If Elizabeth Cochran allowed herself to dream, the future would look something like this:
Every personal computer would double as a seismic monitor. That MacBook at the coffee house, the one used by the guy pounding out a screenplay? Working to detect ground tremors while its user sips a latte. The aging PC gathering dust in the guest room? Ready to catch the next quake.
If Cochran, an earth scientist at UC Riverside, has her way, every time the ground beneath us shakes, those machines would capture its movement and feed the information to a central computer system, creating a rich -- and inexpensive -- portrait of how and where an earthquake is felt.
Such a network could dramatically boost our understanding of earthquakes -- and bring researchers a step closer to an earthquake early-warning system that could give emergency officials vital seconds of preparation as a catastrophic temblor moved through the region.
By harnessing the power of accelerometers -- tiny devices that detect movement, allowing iPhones to flip from vertical to horizontal and Wii devices to function as tennis rackets -- Cochran and her colleagues at Riverside and at Stanford University have begun to build a system that links ordinary computers into a seismic network.
Ideally, Cochran said, “we would have seismometers in every building, or at least on every block. And in tall buildings, we’d have multiple sensors [on different floors]. That way, we would be able to actually get much higher detail, images of how the ground shakes during an earthquake.”
Until a few years ago, most of the research Cochran conducted about ground shaking required grueling field work: digging deep trenches into the earth to install sensors along a fault zone. Installing a simple program on a computer, she said with a laugh, “is quite a bit easier.”
And a lot cheaper. Some newer laptops have accelerometers built in. For computers that don’t, it’s fairly easy to install a $50 sensor with a USB cable that measures movement in much the same way as an accelerometer.
Cochran got the idea for the network from a computer program on a friend’s MacBook. The program, called Seismac, allows people to shake their MacBook and get readings from the computer’s accelerometer. The program is designed for fun -- but Cochran immediately wondered how it could be used to measure earthquakes.
She talked to colleague Jesse Lawrence about transmitting readings from laptop accelerometers into a database. Lawrence, she said, “was like, ‘That’s the coolest thing I have ever heard.’ ” So they created a program that would record quake movements and feed the data to a network.
Already, 1,000 people have signed up to be “Quake Catchers,” the name given to the amateur seismologists who use their computers to track earth movement. Cochran and her colleagues are trying to push the Quake Catchers’ membership toward 10,000. They dream of blanketing California and beyond.
If a temblor struck, say, along the San Andreas fault near the Salton Sea, it would first be felt by a couple of laptops positioned around Palm Desert. Seconds later, a high school science classroom in San Jacinto would record the waves. As the quake traveled, it would trigger sensors at the music library at UC Riverside, a home office in Pomona and eventually, a fifth-grade classroom in El Monte. At every point, the Quake Catchers’ computers would send information on the quake’s size and scope to a computer system monitored by seismologists.
In the event of a huge quake, the network could potentially give areas miles away from the epicenter a few seconds of warning. Shock waves from a quake move quickly through the ground, but electronic signals are far faster, allowing warnings to outrun temblors.
Such notification might allow emergency officials in Ventura to shut off gas and water lines, stop trains and raise fire station doors immediately after a quake hits in the Salton Sea.
Cochran is part scientist and part saleswoman as she crisscrosses the state to persuade people to become Quake Catchers.
She’s attended science teachers’ meetings. She and her team trolled scientific online bulletin boards, trying to talk fellow scientists and students into becoming quake catchers. Cochran also takes her tour into the classroom.
On a recent Wednesday morning, she stood in front of Lezlie Sheskey’s second-grade class at Pachappa Elementary School in Riverside. Dressed in a white blazer and jeans, Cochran, 31, was flanked by graduate students. She is an assistant professor with a weighty doctorate in geophysics and space physics from UCLA, and when she spoke, her deep passion for her subject became clear. As she looked at the row of desks and started talking about tectonic plates, her eyes lighted up, her hands moved quickly to emphasize a point and a smile spread across her face.
Sheskey contacted Cochran after January’s magnitude 7.0 quake in Haiti. Her students, she said, had brought in information about that quake that was “all over the place.” Sheskey invited Cochran and her team because she thought getting involved in the Quake Catcher Network would give them a real understanding of how earthquakes happened.
But the star attraction of the morning was Cochran’s silver MacBook, equipped with the Quake Catcher program. Four colored graphs gyrated wildly as students banged their fists on the table that held the laptop.
“Nice shaking!” Cochran yelled in encouragement.
Before she left, Cochran installed a sensor and the Quake Catcher program on a computer in the corner of the classroom.
Last month, Quake Catchers captured the magnitude 8.8 quake in Chile and a rare 3.8 quake northwest of Chicago.
There are a few Quake Catchers in the Central Asian nations Kyrgyzstan and Tajikistan -- places where “it would be pretty difficult to install a [traditional] seismometer.”
Another sensor was even more remote. For about six months, someone was providing quake data from Antarctica. Cochran was thrilled, but then the data abruptly stopped coming. Cochran thinks a scientist on a long-range project had brought along a laptop with the Quake Catcher program. (For privacy reasons, the program does not identify individual participants, and the data capture gives places but not names.)
Just this week, she and Lawrence sent two grad students to Chile to install 50 more computer sensors there.
As the quake-catching network expands, Cochran is seeing both its promise and its potential limitations.
One of the eternal challenges to building a network of seismometers is how to differentiate between the movement that scientists care about, triggered by the earth’s shifting plates, and the movement they don’t: the vibrations of cars, trucks and even the fists of second-graders.
California’s official seismic network, a collection of about 450 machines situated throughout the state, relies on the sophistication and placement of the pricey equipment. Some monitors are buried underground, or in fallout shelters, or wrapped in Styrofoam in order to silence the ambient vibrations.
The Quake Catcher Network is far less sensitive.
Instead, Cochran said, the scientists who designed the network have programmed computers to record all vibrations, but only upload the information if many computers in the same geographic area record “dramatic shaking.”
That’s another reason why Cochran thinks expanding the Quake Catchers Network is so important. More computers in an area mean more accurate readings for the network.
George Rothfuss, a Yorba Linda resident, became a Quake Catcher last year, not knowing what to expect. But soon after he and his wife, Manya Pierce, joined the network, Yorba Linda was at the center of a swarm of small earthquakes.
The couple’s computers recorded most of the quakes and sent data to the network. Rothfuss posted screen shots on the Quake Catchers’ online bulletin boards like a proud papa. Now, they have become quake-catching proselytizers themselves -- and are sounding a lot like Cochran.
“If every K-12 school in California had sensors running,” Rothfuss said, “it seems to me we could have some sort of early-warning system.”
