According to Icelandic Met Office (IMO) a few smaller earthquakes have followed. However, there are no signs of volcanic tremors and IMO has lowered the aviation colour code from yellow back to green, in accordance with recommended International Civil Aviation Organisation (ICAO) procedures. That is the code when a volcano is in typical background, non-eruptive state. The yellow alert is raised when a volcano is exhibiting signs of elevated unrest, above known background level.
The colour code was raised to yellow on Thursday 29 September, when a very intensive pulse began in the caldera.
Earthquakes in Katla started to pick up the pace earlier this summer (see blog article: Colour Code for Katla Raised to Yellow).
Bárðarbunga is another huge volcano in Iceland which has been showing signs of unrest in recent weeks and months. Yesterday an earthquake of M3.8 occurred in the northern part of the sub-glacial caldera, which is located in Vatnajökull glacier. A few after-shocks followed, the largest one was M3.0 reports IMO. Scientists have detected signs of magma movement into the magma chamber of the volcano, which is at the centre of a 200 km (124 mile) long volcanic system, one of the largest on the planet.
Katla has historically erupted at least once every century and as its last eruption was in 1918.
Before that eruptions at an interval of 13 to 95 years marked the history of Katla.
ICE2017 Team will be keeping a close eye on the recent activity from both Katla and Bárðabunga.