Several of our visitors have received a warning message in recent weeks. This has caused concern amongst some of them because they think it is a warning of an impending eruption. However, that is not the case quite yet. So, why are people getting warning messages about Hekla?
Hekla’s volcanic system is one of the most active in Iceland, having produced about 23 eruptions in historical times. Not all the eruptions occur in the same way, but there seems to be a clear pattern in the eruptions from Mount Hekla. One of the potentially concerning aspects of this pattern is the fact that Hekla does not show major seismic activity prior to the eruption, except when she is ready to erupt. And these signals usually appear 25 to 80 minutes prior to the eruption.
Consequently, seismic activity alone is not enough to monitor Hekla. That is why for many years other techniques have been used to follow what is happening at Hekla’s interior. Other techniques include strainmeters that measure the stress on the ground produced by the extension of a dyke bringing magma to shallower levels; or tilt measurements that quantify the change of slope along a predetermined segment on one of the flanks of Mount Hekla.
The results of these monitoring techniques show that in 2006 Hekla reached the same level of ground deformation as the eruption of 2000, which is the most recent eruption of this system. This technically means that Hekla has been ready to erupt since 2006. Why has she not erupted yet? It is not clear. What we know is that an eruption at Hekla will come sooner than later, and as we have established before, it will come with very little warning, based on historical facts.
Warnings part of a monitoring system
Therefore, it is of utmost importance for everybody to be aware of the situation at hand and understand that Hekla could erupt at any time and, despite the technology and monitoring techniques, there will be very little time once the signals appear. Thus, we need to be ready to act. For now, the messages are just letting us know that we are in the vicinity of Hekla and that she is active and ready to erupt. It is more than likely that when she is ready to erupt, the text we get will be more than just a warning, most likely it will contain some clear commands of what to do.
So, for the time being, be aware of this situation and do not worry if you receive this message. We and the Icelandic MET Office will continue to inform and raise awareness on matters related to volcanic hazards. If you have further questions or concerns about these warning messages about Hekla or any other volcano, please come and see us at the Lava Centre in Hvolsvöllur. We will be happy to answer any question you may have, share a cup of coffee, or just talk about the volcanic and seismic activity of Iceland and the World.
More information on Hekla and a live stream from LAVA Centre can be found at our Guide to Hekla.
More on the Icelandic MET Office’s monitoring of Hekla (From 2016)
By Jorge Montalvo, the LAVA Centre’s Geologist and a specialist on Hekla.