Quake-Catcher Network


Use your laptop to help detect earthquakes. This collaborative initiative to develop a low-cost seismic detection system aims to complement the current system of earthquake sensors installed along major fault zones, taking advantage of the accelerometers built into many newer laptop models. When many computers in an area record motion at once, the program automatically transmits data about the type and intensity of shaking to researchers. This information gives geophysicists a better understanding of how earthquake waves travel through the ground, and could help engineers to design better earthquake-resistant buildings. With enough users, the network could even act as an early-warning system for schools, emergency responders, and others. This project is open to volunteers who have a laptop with a built-in accelerometer (newer Macs and PC laptops), or an external USB sensor such as the MotionNode Accel or JoyWarrior 24F8.

See http://qcn.stanford.edu for more details, or 'Attach Project' http://qcn.stanford.edu/sensor

Sponsors: National Science Foundation, Southern California Earthquake Center, IRIS, UPS

Start date: February 2008


Quake-Catcher Network explained by Sciencentral.com


Seismology is the scientific study of earthquakes and the propagation of vibrations through Earth. Earthquakes occur when a large amount of energy that is built up over time is suddenly released. This energy release usually takes the form of slip along faults, where rocks on different sides of the fault slide in opposite directions. The rupture (or slip) often causes sharp displacements at the fault and shaking in the ground near the fault. This shaking is measured by sensors called seismometers.

The Seismometer Inside

Many 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.

The USB Sensor

Unlike laptops, desktops do not have accelerometers inside. So we connect inexpensive universal serial bus (USB) accelerometers to desktops. The USB sensors use similar to the Sudden Motion Sensors that come in many laptops. USB accelerometers connected to desktops have several advantages over laptop sensors:

  • Desktops are not usually moved around as much as laptops.
  • Desktops are usually placed on the floor or on sturdy desks, but laptops are often on people's laps.
  • Third, the USB accelerometer is physically separated from the keyboard, so typing does not effect the sensor.
  • If the user wishes, the USB sensors can be monitored continuously, not just when the computer is in screensaver mode.
  • A USB sensor can be attached to any desktop with a USB port, not just particular laptops with accelerometers already internal to them.
  • USB sensors can be aligned to north, so we know what directions the X and Y axes actually are.

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).


So far Quake-Catcher Network participant computers have detected earthquakes in Reno Nevada and in the greater Los Angeles area. As the network expands we should be able to detect more seismic events.

QCN Records Reno Nevada Earthquake of April 26, 2008

We are happy to report that two QCN alpha test participants who live in and near Reno Nevada detected vibrations from the recent Magnitude 5.1 earthquake in Reno using QCN software. We're very excited and are currently preparing a paper to show these preliminary results, i.e. that the QCN software seems to detect real seismic events and report to our servers within seconds. Hopefully this is the start of a real system that can be used for advanced warning someday! We're also happy to report that both participants and their laptops are fine!

QCN Testers Detect Quake in Los Angeles

There was a magnitude 5.4 earthquake east of Los Angeles, detected by about 15 machines running QCN. Most machines reported back to the servers with 2-4 seconds of the initial detection trigger. These results (in addition to the previous quake in Reno a few months ago) show great promise for the QCN software! So thanks and keep running QCN!


  1. Elizabeth S. Cochran, Jesse F. Lawrence, Carl Christensen, and Ravi S. Jakka. The Quake-Catcher Network: Citizen Science Expanding Seismic Horizons. Seismological Research Letters, Jan/Feb 2009.

September 25, 2008
This week's issue of 'The Economist' (Sept. 25th '08) has an article on QCN written by Francois Grey of CERN. You can read it online here

QCN Participant Machines Detect Today's San Jose M4.2 Quake
March 30, 2009
At least four QCN participant's machines detected today's San Jose earthquke. Also for the first time the external USB JoyWarrior sensor was used to detect a quake (it's previously just been Mac laptops). So keep running QCN and thanks for participating!

Hawaii Quake Detected; QCN Is Now 'Non-Alpha'
April 21, 2009
A few QCN participants caught the recent M5.1 quake in Hawaii. Also as of today I am removing the 'alpha test' status of the Quake-Catcher Network, although the URL will remain the same so you do not have to reconnect/reattach. The credit stats should now be tracked by boincstats.com

QCN Participants Detect M4.0 earthquake in Yorba Linda, California
April 24, 2009
Two Quake-Catcher Network participants felt and recorded yesterday's magnitude 4.0 earthquake in Yorba Linda, California (southern Cal, southeast of Los Angeles). You can view some of the data at this link. They are only about 4 km / 2.4 miles from the epicenter, so it was a good test of QCN and the JoyWarrior USB sensors! Happily everyone is OK with just a few plates shaken up etc.

QCN Participant Detects M4.5 earthquake in Southwest Germany
May 5, 2009
A Quake-Catcher Network participant detected a magnitude 4.5 earthquake in SW Germany, near the borders of France and Switzerland using his JoyWarrior USB sensor and QCN/BOINC. This is a fairly rare event to capture on QCN and we thank him and others running QCN! The participant's computer was only 10km from the epicentre.

Links of Interest

Donate or Buy A USB Sensor: http://qcn.stanford.edu/learning/requests.html

Quake-Catcher Network In the Classroom

Learning Center

QCN is not only a research tool, but provides an educational tool for earthquake science. A central mission of the Quake-Catcher Network is to provide scientific educational software and hardware so that K-12 teachers, students, and the general public can better understand and participate in the science of earthquakes and earthquake hazards. With greater understanding, teachers, students, and interested individuals will be able to share their new knowledge, resulting in continued participation in each project, and better preparation for earthquakes in their homes, businesses, and communities.

The primary education outreach goals are:

  1. To present earthquake science and earthquake hazards in a modern and exciting way

  2. To provide teachers and educators with seismic sensors, interactive software, and written materials to assist in Earth science education

Educational Material


We have developed a version of the software specifically to use in the classroom called QCNLive. Teachers and students use the QCNLive software with either a laptop (with an internal accelerometer) or a desktop computer with a USB sensor. QCNLive does not communicate with the QCN server so that students can simulate as many earthquakes as necessary to understand the motions that earthquakes create.

Lesson Plans

QCN designed lessons for teachers to use in the classroom to supplement earthquake curriculum. Through interactive experiments, students will learn about earthquakes and the hazards earthquakes pose. For example, students can learn how the vibrations of an earthquake decrease with distance by jumping up and down at increasing distances from the sensor and plotting the decreased amplitude of the seismic signal measured on their computer. The QCN provides a natural way to engage students and the public in earthquake detection and research. Click here for lesson plans and activities.

USB Sensor Pool

While many laptop computers have internal accelerometers, an external sensor is a much safer teaching tool. Students can move the sensor any which way without the potential of damaging the laptop (or the fear of the teacher limiting their investigation with a laptop). The USB sensors are easily plugged into the USB port on desktop computers and interact with the QCNLive software as well as QCN software that reports to the QCN server.

K-12 USB Sensor Request

If you are a science teacher at a K-12 school, you can request a USB sensor and accompanying QCN software with a $5 donation. K-12 teachers at underserved schools can apply for free USB sensors. If you are interested in donating a sensor to a educational or public institution or other worthwhile entity, please contact read more here.

Sensor Donations

If you are willing to donate to QCN, your gift will go toward purchasing USB sensors for public or educational organization (K-12 schools, libraries, fire stations, police stations, public utility companies, universities, museums, and more). The sensors also provide a stable backbone so that QCN can detect earthquakes faster and more reliably. If you donate more than $49, you can request that a sensor go to the location of your choice (contingent on a the recipient participating in QCN). To donate a sensor now please read more here.

Apply for a USB Sensor

If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in receiving a sensor, please contact Jennifer Saltzman to be added to the list. We will contact you when the sensors are available.