Volunteers are needed for QCN (Quake-Catcher Network)

About QCN: Laptop Network

The Seismometer Inside

qcn-lt2Many laptops currently have a Sudden Motion Sensors or Active Protection Systems inside them. While these sensors were originally designed to help protect the computer’s hard disk in case they are dropped or shaken, seismologists can use them to detect earthquakes.  The Quake-Catcher Network (QCN) links participating laptops into a single coordinated network that can detect and analyze earthquakes faster and better than ever before.  The laptop network is the least expensive seismic network in the world.  Because volunteers (individuals like you) donate idle CPU time on laptops with these sensors already built in, each additional sensor doesn’t cost a thing!

Does My Laptop Have A Sensor Inside?

If you have a Macintosh laptop manufactured after January 1, 2005 then you probably do.

If you have a Thinkpad manufactured after 2003, then you probably do.

If you have a HP laptop was produced since January 2007, you may have a 3D Motion Data Protection System.

If you have an Acer laptop produced since January 2007, you may have a Gravisense accelerometer on board.

Soon we may have a web-based open-source program to tell you whether your laptop has an accelerometer or not.

Three Directions

The sensors can measure acceleration in three directions. The easiest way to think of these directions is as the 1) up/down 2) front/back, and 3) side to side motions bobbing motions of a boat. With these three components of direction, it is possible to find the direction of the acceleration. If your laptop is not level (or horizontal), the directional acceleration may not return a zero value when it really should. This is why our software zeros each directional acceleration before it begins to monitor the sensor.

Communications and Data Transfer

Laptops connect to the Quake-Catcher Network over the Internet. Typically, when the QCN software is running, there isn’t much need to transfer the data to our headquarters. Instead, the laptop monitors the data locally for new high-energy signals and only sends a single time and a single significance measurement for strong new signals. If our server receives a bunch of these times and significance measurements all at once, then it is likely that an earthquake is happening. If the server receives only a time and significance measurement from one laptop, then the server knows the laptop was shaken by something smaller and more local (like your sister running by, or the door slamming).

Join the Laptop Network

You can join the network if you have a laptop with an internal sensor.

Ever-Changing Laptop Locations

Laptops continuously move with the people who use them. So how does the Quake-Catcher Network know where the laptop is? Well, several ways. First, if you are nice enough to tell us the places where you use your laptop most often, then it takes a lot of the guess-work out of equation.  Second, your computer has an IP address that connects to the internet through a specific server.  Based on your IP address and the server location, we can determine your rough location.  Finally, we hope to add a “Where Were You?” site to verify that your laptop was where we thought it was when the earthquake occurred.

Timing is Everything

Every 15 minutes the Quake-Catcher software checks to see if your laptop’s clock is synchronized with the clock here at the Quake-Catcher Network. The clock here at the Quake-Catcher Network is synchronized with an atomic clock, so the whole network is always on time.  Don’t worry, we don’t change the time on the laptops, we just measure the minute difference between your laptop’s time and the time here at QCN.

Power Outage

The power sometimes goes out after earthquakes because of broken power lines. If the power goes out, your laptop can run on batteries for a little while. Because your internet connection will disconnect when the power drops, the QCN software will store the seismic data it records locally on the laptop until internet connection is restored.


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