What’s Going On in The Gulf of Aden?

USGS is reporting a very unusual swarm of significant earthquakes starting early this morning in the sea between Africa and the Arabian peninusla, right off the coast of Yemen, and in one of the world’s most important and busiest shipping lanes.

But, earthquake swarms happen, even in places that are not normally known for seismic activity. What’s unusual about this particular group of earthquakes?
In this case, it seems that the vast majority of the quakes are happening at almost exactly a depth of 10 kilometers; over 20 earthquakes have occurred at that depth since the swarm began. I’m no statistician, but that seems like a pretty exceptionally unlikely scenario, especially when the region was entirely quiet in terms of seismic activity as of yesterday. It would definitely be interesting to see what real geologists make of it.
Below is a screenshot from the USGS earthquake tracking site, taken early afternoon today, and covering today and yesterday’s major seismic activity worldwide; We’ll update with more information if anything newsworthy develops.