Signs and Portents of Iceland

Icelandic volcanoes are all about long term projections. They do not do things in the short run, before any eruptions you will see either several intrusive episodes like at Eyjafjallajökull, or you will see signs of steadily mounting pressure prior to an eruption. For some Icelandic volcanoes these two processes goes on for decades, or…

Unrest at Hekla

At 07.55.04 Hekla suffered an earthquake of M0.9 at 0.7km depth under the west slope of Hekla proper. After that followed two badly localized small tremors before a second earthquake with a temporary solution of M0.6 at the same place and depth. After that came a final (so far) small tremor. This follows after ten days…

Eldgja: Feeding the Fire

The facts of Eldgja are well established. We know approximately when it happened, where it happened, how much lava, tephra and sulphate was ejected. We have found the tephra in Greenland. We think we know the human impact over much of the northern world, arising from three years of winter. But on other aspects, our…

Eldgja: Eruption dating

The previous post described what we think we know about the Eldgja eruption. Our knowledge about one of the largest eruptions in Iceland is somewhat limited, surprisingly so given that Iceland was already well populated. One of the few things which seems secure is the date. Eldgja is believed to date to 934 AD, continuing…

The Eldgja Eruption: Iceland’s Baptism by Fire

Iceland is the most volcanic place in the world. Explosive eruptions, from many different volcanoes, are common, unpredictable and, when seen from afar, exciting. But don’t be fooled. These volcanic explosions are small fry, and mostly harmless. Less common but far more devastating are the other type, responsible for 80% of all Icelandic lava and…

Countdown to Grimsvötn

I have lately read a lot of comments about Iceland being boring and calm. In reality nothing could be more wrong, Iceland is brimming with activity. So, let us take a quick look at some interesting volcanoes before we go to the namesake of this article. Volcanic activity in general If we start in the…

Who ordered a Bárðarbunga?

After writing the Woolly Mammoth Guide to Icelandic Volcanism I vowed to not write about Iceland for a while. That comment bit me in the posterior rather quickly. Since the cessation of the Holuhraun eruption the central volcano Bárðarbunga has been highly seismically active. Many people have fervently believed that this has been due to…

Reinterpreting Grimsvötn

In the previous part we learned that Grimsvötn indeed is able to produce large scale eruptions as we looked closer into the Saksunarvatn tephras. The first part can be found by following the link below. http://www.volcanocafe.org/grimsvotn-the-saksunarvatn-tephras/ This time we will look into what this new information might mean for the future eruptions of Grimsvötn. But…