M5.4 earthquake 73 km SSW of George Town, Cayman Islands
A magnitude 5.4 earthquake struck 73 km SSW of George Town, Cayman Islands on Sat, Oct 16, 2021, 1:27 PM EST (18:27 UTC), 10 km (6 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.4 (Mww, W-phase moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2021-10-16 18:27:28 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 18.701° N, 81.705° W
- Region
- Cayman Islands
- Felt reports
- 14
- Strongest shaking
- III, weak shaking
- PAGER alert
- Green
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 5.4 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.041 · 56 stations |
| 5.3 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.6 | Mi | NOAA Pacific Tsunami Warning Center | First automatic solution · Reviewed · 14 stations |
| 5.2 | Mwr, regional moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
| 5.2 | Mwb, body-wave moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
| 5.3 | Mww, W-phase moment | USGS, automatic first solution | First automatic solution · Confirmed |
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- III, weak shaking
- Peak ground acceleration
- 0.9% of gravity
- Peak ground velocity
- -0.6 cm/s
- Map
- Automatic
Did you feel it?
14 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.
Estimated impact
The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.
- Alert level
- Green: little or no damage or loss of life expected
| Range | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
| Range, million USD | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Oblique normal
- Moment magnitude
- 5.4 Mww
- Nodal plane 1
- Strike 324°, dip 27°, rake -129°
- Nodal plane 2
- Strike 185°, dip 69°, rake -72°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 5.5 km horizontally, 1.8 km in depth
- Magnitude uncertainty
- ±0.04
- Depth from
- Operator assigned
- Station coverage gap
- 26°
- Stations used
- 257
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.4 and up: 0 in the 60 days after this one and 0 in the 30 days before it.
None recorded.
Earthquakes todayCayman Islands earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000fv9g (also filed as usauto6000fv9g, pt21289001, iscgem621204681). Read Sun, Oct 4, 2026, 5:11 PM UTC.