August 6, 2008
Network Uses Laptop Sensors To Detect Earthquakes
A new network is being used to detect earthquakes through use of a laptop's tiny accelerometers.
Accelerometers have been used in laptops and cell phones to prevent damage to the hard drive if the machine is dropped.
Now, scientists have created the Quakecatcher Network, built on the combination of readings from accelerometers.
The network already showed its potential last month when it accurately detected last month's quake in Los Angeles.
"When you accidentally knock your laptop off the desk, the accelerometer is detecting a large, strong new motion," said Jesse Lawrence, assistant professor of geophysics at Stanford University.
However, accelerometers are perfect for monitoring earthquakes, Lawrence added.
The Quakecatcher Network is in its early stages, as only three laptops have been fully connected. Dr Lawrence said that having more computers connected to the network would bring a more accurate reading.
While an individual machine "can't necessarily tell the difference" between a quake and someone just getting up quickly and knocking their laptop forcefully, Dr Lawrence explained the key is the number of machines networked together.
"If there's just a few of them, then the server will know it's just people knocking their laptops around accidentally," he said.
"But if we're flooded with a large number of triggers, then we'll know that there is a large, significant earthquake in the area."
The sensitivity is variable, depending on distance from the quake.
Once movement is detected, the information is sent to the server, where it is verified as to whether it is an earthquake.
Although this may only provide a few moments' warning, every second counts in such a situation.
"If it is an earthquake, we could potentially send out signals to those who need it even before the energy from the quake has expanded out from the epicenter to those other people," Dr Lawrence said.
"In California, we train pupils in schools to jump underneath desks when there's an earthquake drill.
"We can do the same thing in all sorts of varieties of situations, and those few seconds can count."
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