Thursday, December 8, 2011

Still watching Katla

It has been a little while since I wrote about the possible eruption of the Katla volcano in Iceland. For a while it appeared that the increased frequency of earthquakes and their growing magnitude, was leading toward an eruption. Since then the mountain has become somewhat quieter; but the earthquakes remain focused around the caldera, and continue to occur at a higher than background rate. Looking at the pattern over the past 24-hours, there is still a strong linear component to the earthquake pattern, which would tie in the continue evolution of fissures along the edge of the caldera.

Earthquakes around Katla in 24-hours (Icelandic Met Office ).

Jón Frímann does not expect this activity to lead to an imminent eruption, nor do I. But the continued linear nature and focused activity around the caldera is indicative of an ongoing preparation for an eruption. However we are talking about geological events, where time has a somewhat different meaning. Imminence is more likely therefore to be months, rather than days. Yet, as Jon notes, normally winter is a period of quiescence and this year we have not seen that. So I continue to expect an eruption of some significant size, it is just not clear when.

Revisiting the site a day later, there is still a lot of ongoing focused activity, though not yet strong enough to show any immediate large scale activity.