General Discussion
In reply to the discussion: Word is that Kick 'em Jenny is about to erupt [View all]starroute
(12,977 posts)I know Grenada is at the other end of the island chain from Puerto Rico, but I've been watching that swarm for a while and wondering what it means. Currently usgs.gov shows 22 quakes between 2.6 and 3.8 magnitude just north of Puerto Rico over the last 24 hours. That's a lot.
On edit: There's some technical discussion of the underlying geography here:
http://earthquake.usgs.gov/earthquakes/eventpage/pr15204002#general_summary
"Moving east and south, the plate boundary curves around Puerto Rico and the northern Lesser Antilles where the plate motion vector of the Caribbean plate relative to the North and South America plates is less oblique, resulting in active island-arc tectonics. Here, the North and South America plates subduct towards the west beneath the Caribbean plate along the Lesser Antilles Trench at rates of approximately 20 mm/yr. As a result of this subduction, there exists both intermediate focus earthquakes within the subducted plates and a chain of active volcanoes along the island arc. Although the Lesser Antilles is considered one of the most seismically active regions in the Caribbean, few of these events have been greater than M7.0 over the past century. The island of Guadeloupe was the site of one of the largest megathrust earthquakes to occur in this region on February 8, 1843, with a suggested magnitude greater than 8.0. The largest recent intermediate-depth earthquake to occur along the Lesser Antilles arc was the November 29, 2007 M7.4 Martinique earthquake northwest of Fort-De-France."