January 28, 2020 Earthquake: Granma, Cayman Is, Jamaica, Cuba

Ref #13456:

Tectonic Summary

The January 28, 2020, M 7.7 earthquake in the Caribbean Sea to the south of Cuba and northwest of Jamaica occurred as the result of strike-slip faulting on the plate boundary between the North America and Caribbean tectonic plates. Preliminary focal mechanism solutions for the earthquake indicate slip occurred as the result of left-lateral motion on a steep fault striking towards the east-northeast, or as the result of right-lateral motion on a steep fault striking towards the south-southeast. The fault plane striking approximately east-west is consistent with the orientation of the regional plate boundary; this transform structure is named the Oriente Fault. At the location of this earthquake, the North America plate moves to the west-southwest with respect to the Caribbean plate at a rate of approximately 19 mm/yr.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Strike-slip-faulting events of the size of the January 28, 2020, earthquake are typically about 170x25 km (length x width).

Five other earthquakes of M 6 or larger have occurred within 400 km of the January 28, 2020 event over the preceding century. These include a M 6.8 earthquake in December 2004, 280 km to the west of today's earthquake, and a M 6.2 event in May 1992, almost 100 km to the east of today's quake. Likely because of their location away from land and major population centers, none of these earthquakes are known to have resulted in shaking-related damage or fatalities.

One house destroyed and at least 300 buildings damaged in Cuba. Minor damage to some buildings in western Jamaica. Some roads cracked and a tsunami with a wave height of 0.11 m was recorded at George Town, Cayman Islands. Buildings swayed at Miami and seiches observed in southern Florida and Louisiana, United States.

Green Island, Hanover, Jamaica - CDI: 7; Wakefield, Trelawney, Jamaica - CDI: 6; East End, _no region, Cayman Islands - CDI: 6; Bodden Town, Grand Cayman, Cayman Islands - CDI: 5; Lucea, Hanover, Jamaica - CDI: 5

Ref #12622:

Several sinkholes opened up at various points around Grand Cayman, causing damage to vehicles and at least one property.

The governor indicated there had been some structural damage on both Cayman Brac and Grand Cayman. He said the Cayman Islands Fire Service and Public Works Department were responding to those incidents and the police helicopter was conducting aerial surveys of the island.

Water services were interrupted in parts of Grand Cayman, due to damage to water pipes.

Ref #12623:

At least two parishes in Western Jamaica have reported structural damage to buildings.

Ref #12624:

In Niquero, Granma Province of Cuba, around 300 homes suffered cracks in the walls and roofs, with one home suffering complete collapse.

Other buildings like primary schools also were impacted

Ref #13213:

At 19:10 on January 28, 2020 (UTC), a large earthquake measuring MW7.7 (Harvard CMT) with a focal depth of 14.8 km, struck the Caribbean Sea region (19.421° N, 78.763° W) between Jamaica, the Cayman Islands, and Cuba. According to reports, the strong shakes were felt across many Caribbean countries, especially those south of Cuba and northwest of Jamaica, as well as in the Cayman Islands. They were also felt as far away as the state of Florida in the USA and in parts of Mexico [...] According to social media reports, the earthquake had a significant local impact on the Cayman Islands, causing some damage to buildings, roads, and sewage pipes, as well as creating massive sinkholes.

Ref #13727:

90 million USD in economic loss