M5.1 Earthquake near George Town, Cayman Islands — 18 July 2026

Moderate earthquakes can damage poorly built or unreinforced structures near the epicentre, while well-engineered buildings typically escape serious harm. Shaking is often strong enough to wake sleeping residents over a wide area.

A magnitude 5.1 earthquake radiates roughly 674 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 401, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.

What the magnitude scale actually measures →

The epicentre was located at 17.9439, -81.5431 — 149 km south of George Town. The closest other recorded event was a magnitude 4.3 earthquake 56 km west-southwest of here on 09 February 2025.

At 10 km this was a shallow earthquake. Shallow events release their energy close to the surface, so for a given magnitude they produce noticeably stronger shaking — and more damage — than deeper ones. Roughly three quarters of all earthquakes worldwide occur at shallow depths.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size can be felt widely and may cause minor local damage. Its shallow focus makes stronger surface shaking more likely than for a deeper event of the same magnitude.

Read more on how focal depth changes what you feel →

The USGS record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M5.1 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.

How earthquakes generate tsunamis, and what the alert levels mean →

No further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event.

19 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 7.6 event near George Town on 08 February 2025. This M5.1 event released about 5,623 times less energy than that event.

How long aftershock sequences last, and how large they get →

This earthquake is part of the July 2026 worldwide record. Browse the full monthly archive to compare periods.