Seismic activity upswing studied

2 earthquakes in 1 month unusual for Cuba

KEY BISCAYNE, Fla. – At the University of Miami Rosenstiel School of Marine and Atmospheric Science, students have been tracking the upswing in seismic activity in the Caribbean, especially off the coast of Cuba.

For an island that rarely experiences earthquakes, it was hit by a 4.3 magnitude quake off the island's north coast Tuesday night, and that's the second in a month.

"Two in one month, that's highly unusual," said Dr. Greg Eberli, professor of marine geology and geophysics.

Cuba sits west of both major plates -- the North American plate and the Caribbean plate.

Its earthquake pattern is nothing compared to the constant tremors affecting the Dominican Republic, Puerto Rico and other islands along the top of the Caribbean plate.

In the past week alone, there have been more than 10 tremors -- none particularly strong, but concerning to many who think they could be a sign a massive earthquake is imminent.

Eberli said science does not support that.

"While these small earthquakes can be a sign something big is coming, sometimes it's a sign the stress gets relieved in small bursts," Eberli said.

When Haiti was devastated by the massive 7.0 magnitude earthquake four years ago, there was no increase in seismic activity in the weeks before.