Katla volcano (Iceland): harmonic tremor could indicate a small eruption
Volcanic tremor (a low frequency vibration often caused by magma rising to the surface) has been observed under Katla volcano in southern Iceland, Jón Frímann reports on his Iceland volcanoes blog (see below), closely following seismic activity in Iceland recorded both by national instruments and his own private geophone network.
Mon, 20 Feb 2012, 22:5322:53 PM | BY: T
According to Jón, there are 2 possible explanations: one could simply be an increase in hydrothermal activity in the northern part of Katla volcano.
The second could be magma movements at depth although there have been no significant earthquakes that usually would accompany an intrusion or small (sub-glacial) eruption, although this still could occur in the near future as often observed in the past during similar episodes of tremor followed by earthquakes.
The last minor eruption at Katla volcano was on 6 September 2011, and caused a small glacial flood.
Sat, 18 Feb 2012, 23:34
Sat, 18 Feb 2012, 08:56
Picture of the Day 18 Feb 2012: Giant petrified tree about 5 m in diameter on Lesbos island, Greece (July 2011)