The three Cayman Islands, Grand Cayman, Cayman Brac and Little Cayman, are located in the western Caribbean about 150 miles south of Cuba, 500 miles south of Miami, Florida, and 165 miles northwest of Jamaica.
Grand Cayman is the largest of the three islands with an area of about 75 square miles. It is approximately 22 miles long and is about four miles. at its widest point. Grand Cayman features a shallow, reef-protected lagoon known as the North Sound, and it has an area of approximately 35 square miles. The highest point (natural feature) on Grand Cayman is about 65 feet above sea level.
Cayman Brac lies about 90 miles east-northeast of Grand Cayman. It is about 12 miles long with an average width of just over 1 mile and has an area of about 15 square miles. Its topography is the most spectacular of the three islands. The Bluff, a massive central limestone outcrop, rises steadily along the length of the island up to 150 ft. above the sea at the eastern end. Little Cayman lies five miles west of Cayman Brac and is approximately 10 miles long with an average width of just over 1 mile. It has an area of about 11 square miles. The island is low-lying with a few areas on the north shore rising to 40 ft. above sea level.
There are no rivers on any of the islands. The coasts are largely protected by offshore reefs and in some places by a mangrove fringe that sometimes extends into inland swamps.
Geographically, the Cayman Islands is part of the Cayman Ridge, which extends westward from Cuba. The Cayman Trough (Cayman Trench, Barteltt Deep), the deepest part of the Caribbean at a depth of 25,217 ft, separates the three islands from Jamaica.
The islands are also located on the plate boundary between the North American and Caribbean tectonic plates. The tectonic plates in Cayman’s region are in continuous lateral movement against each other. This movement, with the Caribbean plate travelling in an eastward direction and the North American plate moving west, limits the size of earthquakes and there has never been an event recorded of more than magnitude 7.
It is not unusual for minor tremors to be recorded and many residents don’t even notice them. However, in December 2004 a quake of 6.8 magnitude rocked Grand Cayman and was felt by everyone. The earthquake, short in duration, opened some small sinkholes but otherwise didn’t cause any damage.