[Island Chris]

There was a M5.1 a couple of days ago, and then a M6.1 in last 24 hours, followed by a bunch of aftershocks, between Spain and Morocco in the Mediterranean Sea. The 6.1 is strike-slip. This is the plate boundary between Africa and Eurasia. It is known to have a strike-slip component, along with some thrusting.

http://earthquake.usgs.gov/earthquakes/e...al_summary 

Farther east, south of Greece, eastward to south of (western) Turkey, there is a subduction zone on this plate boundary.

The quakes in the swarm are pretty far apart. I did not check the location errors, which could explain this.

Chris