Prediction vs. Early Warning
Two very different technologies that are often confused - and why the distinction matters.
What Is an Earthquake Early Warning System?
Earthquake early warning (EEW) systems such as ShakeAlert (US West Coast), Japan's J-Alert, or Mexico's SASMEX detect the initial P-wave of an earthquake that has already started and transmit alerts before the slower, more destructive S-waves arrive. The time window is seconds - sometimes less than ten seconds. EEW is a real-time detection and notification system, not a prediction system.
EEW is well-established, operationally deployed, and saves lives. It is not controversial. It does not, however, give advance notice: the earthquake must begin before the alert can fire.
What Is Earthquake Prediction?
Earthquake prediction - in the scientific sense - means issuing a statement before an earthquake occurs, specifying some combination of location, magnitude, depth, and time window. A prediction is only scientifically meaningful if it is:
- Issued prospectively - before the event, not after.
- Specific enough to be falsifiable - a prediction that covers all of California for all magnitudes at any time is not a testable claim.
- Evaluated against a pre-defined protocol - the scoring rules must be fixed before the prediction window closes.
How Seismikon Fits
Seismikon produces prospective predictions issued up to 48 hours in advance, with specific predicted coordinates (latitude, longitude), focal depth (km), and magnitude range. Each prediction is evaluated against real USGS earthquake catalogue data using a published evaluation protocol after the prediction window closes.
This is complementary to EEW - it operates on a completely different timescale (hours, not seconds) and serves different use cases: pre-event preparedness, supply chain contingency, infrastructure staging, and risk pricing.
Why the Distinction Is Often Confused
In public discourse, "earthquake warning" is used loosely to describe both systems. Journalists and commentators frequently conflate the two, which leads to both overclaiming (treating a prediction as a guaranteed alert) and underclaiming (dismissing prediction research because deterministic precision is not achievable). Seismikon specifically avoids the term "warning" in its operational communications to preserve this distinction.