| 2018 Swan Islands earthquake | |
| Timestamp: | 2018-01-10 02:51:31 |
| Isc-Event: | 611634051 |
| Anss-Url: | us1000c2zy |
| Local-Time: | 20:51:31 PM CST |
| Magnitude: | 7.5 |
| Depth: | 19km (12miles) |
| Location: | 17.469°N -83.52°W |
| Type: | Strike-slip |
| Affected: | Honduras Guatemala Belize Cayman Islands |
| Casualties: | None |
On 9 January 2018, at approximately 8:51 p.m. local time (02:51:10 January UTC), a 7.5 earthquake struck in the Yucatán Basin of the Caribbean Sea, east of Great Swan Island off the coast of Honduras.[1] The earthquake was felt across Central America, and rattled windows in Tegucigalpa.[2] The earthquake was also felt in the Cayman Islands.[3]
Tsunami advisories were issued for certain areas by the U.S. Tsunami Warning Center. They were later cancelled after further monitoring.[4] No tsunami was generated since the earthquake was an almost pure strike-slip on a near vertical plane, producing little upward movement of the sea floor that would cause a large displacement of water.[5]
The earthquake occurred at a depth of around on a transform fault zone known as the Swan Islands Transform Fault in the Cayman Trough, where it forms part of the boundary between the North American plate and the Caribbean plate.[1] The area just to the west also produced a large earthquake in 2009 that measured 7.3 on the moment magnitude scale.[6] According to a finite fault model created by the U.S. Geological Survey, the earthquake generated a maximum slip of 24 meters in a compact rupture zone. Three sub-events were discovered during the rupture process, the third of which, occurred at a velocity exceeding that of the shear wave. Propagating at 5 km/s, faster than the shear wave velocity of 4 km/s, the event is classified as a supershear earthquake.[7]
No major damage was reported. However some homes suffered cracks in walls.[8]
A tsunami was observed with maximum heights of 0.4m (01.3feet) in Roatan Island, Honduras.[9] A 0.2m (00.7feet) surge was observed in George Town, Cayman Islands.