Since 17-May-2010 until this post 9-July-2010, there have been approximately 96 earthquakes at the Katla volcano site within the region of the Myrdalsjokull glacier. Of the 96 earthquakes, 27 have been within the Katla caldera. The image shows the earthquake locations with respect to the past volcanic eruption sites of 1755, 1823, and 1918. There was also a suspected region of eruption during 1955 which never broke through the ice glacier. It is located on the eastern edge of the caldera.
As you can see, only a few of the earthquakes occur directly underneath a previous eruption location, while the majority occur around the perimeter, particularly the east-northeast perimeter. Several others are scattered in other locations within the caldera.
It is interesting to note that of the approximate 96 Katla earthquakes since 17-May, the majority have occurred just off of the northwest rim of the caldera as you can see in the image above.
Katla has been fickle during the past number of weeks in that there have been days when hardly an earthquake has appeared, while there have been other days that have been fairly active. There was one stretch of several weeks that was very quiet, while during the past several days there has been quite a lot of activity, much more than average since I’ve been watching this.
Katla historically erupts following the eruption of Eyjafjallajokull (which first erupted April 14). Katla is about 10 times more powerful, and has the potential to cause worldwide disruption.