How Sonic Boom Detection Works

What is a sonic boom?

A sonic boom is the thunder-like sound produced when an object travels faster than the speed of sound. The most common sources are SpaceX Falcon 9 rocket boosters returning to land after launch, though military jets and other supersonic vehicles can also produce them.

Unlike earthquakes, sonic booms travel through the air rather than the ground. But the effect on people is similar — a sudden, startling boom that shakes windows and walls. Many people who feel a sonic boom initially think it was an earthquake.

How we detect them

We operate one of the most visited earthquake information sites on the web. When people feel something that might be an earthquake, many of them immediately visit the site to check.

We monitor web traffic in real time, divided into geographic grid cells based on visitor location. When a cluster of nearby cells all show a sudden spike in traffic at the same time, it usually means people in that area just felt something. Our detection system identifies these spikes automatically.

By cross-referencing the location and timing of traffic spikes with known rocket launches, military flight schedules, and seismic data, we can determine whether the event was a sonic boom, an earthquake, or something else.

Confirmed vs. suspected

Events are classified as confirmed when we can match them to a known source — typically a SpaceX launch with a booster landing. Events are suspected when the traffic pattern looks like a sonic boom (localized, sudden spike with no corresponding earthquake) but we haven't identified the specific source.

How is this different from earthquake detection?

The same traffic-spike detection system catches both earthquakes and sonic booms. The key difference is what happens after detection: earthquakes show up in USGS seismic data, while sonic booms don't. When we detect a traffic spike with no corresponding seismic event, and the pattern matches a boom (sharp, brief, geographically compact), we classify it as a sonic boom.

Technical details

Our detection grid uses 0.5-degree latitude/longitude cells (roughly 35 miles / 55 km). Traffic is monitored in 10-second intervals. A detection fires when a cluster of adjacent cells all exceed their baseline traffic levels by a significant multiplier, with enough unique IP addresses to rule out bot traffic.

Contact

Questions, tips, or corrections? Email us at .