Not Like Other Warnings

Warnings are currently provided for many natural hazards. You might think earthquake warning is just one more, but earthquake warning is very different from every other natural hazard warning.

The table below compares earthquake warning to other natural hazard warnings. The differences are clear to see.

San Francisco, 1906 damage
Tornado funnel
Tsunami overtopping seawall during Tohoku, 2011
Flood damage in Lyons, Colorado
Wildfire near El Cajon, CA
Satellite image of Hurricane Fran
Warning Timesecondsminutesminutes to hourshourshours to daysdays
Observable Signsnoyesyesyesyesyes
Multiple Sourcesnoyesyesyesyesyes
Precursor Warningsno1-2 daysno2-3 days1-2 days4-10 days
Response Optionsshelter immediatelyimmediately shelter or fleeplan, then shelter or fleeplan, prepare, then fleeplan, prepare, then evacuateplan, prepare, then shelter or evacuate

Warning Time

The time from the receipt of an alert requiring some action and the onset of the disaster at your location.

Observable Signs

Whether you can tell that the disaster is approaching by looking at the sky, smelling for smoke, or some other obvious sign.

Multiple Sources

The number of different sources of information about the approaching disaster. This indicates the level of trust a warning source must be given.

Precursor Warnings

A series of increasingly urgent messages describing the danger - such as advisory, watch, warning, evacuate - without which the warning is a surprise.

Response Options

Whether you must act immediately or will have time to plan, gather belongings, and then shelter or make your escape.

Consequences of These Differences

Our approach to earthquake warning is based on addressing these differences with other natural hazard warnings.


Unlike for all other warnings of natural disasters, there is no way to confirm an earthquake warning and there is no time to decide how to respond. There must be an immediate response. Every effort must be made to build and maintain trust.

False Alarms

If people don't trust the warning, they won't respond immediately. False alarms must be infrequent or absent. Our system has been designed from the start to prevent false alarms. Our customers have had none in the 15 years our products have been in use.

Rapid Communications

Existing warning systems, like the Emergency Broadcast System, are too slow for earthquake warnings. Since the warning time may be only a few seconds, communications must take far less than a second to avoid wasting precious time. Our system delays are under 1/4 second.

Automated Control

Automation is needed to take maximum advantage of what may be a small amount of warning time. We focus on automated actions. Our warning appliances interface with factory, building, and process automation systems.


Communications security is essential when using earthquake warning to automatically protect property. Malicious actors could wreak havoc if the warning system has weak security. We focused on security from the start and it permeates all aspects of our system design.

Training and Education

People must be trained to respond immediately to the warning since there may not be much time before the serious ground motions begin. We work with emergency managers and disaster preparation people to promote and support earthquake warning training.