A plot of the recent swarm of earthquakes at El Hierro in the Canary Islands that began around March 18, 2013. This swarm is located off the western shore of the island, rather than the southern tip where the 2010-12 activity was centered. Image: AVCAN. Over the last few weeks, many people have been noticing a sharp increase in earthquakes under El Hierro in the Canary Islands. If you recall, in 2010-12, the volcanic island was the home of an offshore submarine eruption that produced some stunning drifts of volcanic tephra and floating "coconuts" of inflated sediment coated in lava. That eruption (in the broadest sense) lasted until March 2012 and since then, beyond some minor earthquake swarms that didn't lead to any new eruptive activity, life has gone back to normal on El Hierro.
Histogram of the recent earthquakes at El Hierro, showing the sharp increase after March 18, ...