The 3 x 4½ km summit caldera of Mount Katmai, Alaska, that formed after the 1912 VEI 6 Novarupta eruption (Wiki)

Calderas

This is a re-post that has been re-posted before. But we attract new readers and sometimes it is worth republishing something. Especially since this is about Icelandic (and other) calderas, something that has been raised in the comments recently. This post was originally written during the Holuhraun eruption and associated Bardarbunga collapse, and you will…

The Hotness of Grimsvötn

As far as volcanoes go, we like to think of them as immutable giants that rarely if ever change. We like to see Grimsvötn as a glacier covered giant of a volcano, that almost always produce moderate ashy eruptions, that are relatively speaking short-lived. Yes, once upon a blue moon it will do something big,…

Taal Update – Ongoing Intrusion

Guest post from Héctor (DustDevil). There will be a further update either later today or tomorrow as events have changed since Héctor wrote this post. The Main Crater of Taal seems to have calmed down, doesn’t it? However fissures are breaking the ground apart, the river dries, Lake Taal falls and strong earthquakes keep coming.…

The rise and fall of Anak Krakatau

It was the largest volcanic eruption since the start of the world-wide web. The invention of telegraphy in the 1850’s had made long distance connections instantaneous. It changed the world. Newspapers were the most obvious beneficiaries, being able to bring gossip news from far away places. And in this landscape, Krakatau exploded. 36,000 people died…

Living dangerously: another Grimsvotn prediction

  Grimsvötn is heading for an eruption. There can be no doubt about that. Of course, it is always heading for an eruption. This volcano has ADHD. For Grimsvötn, more than a decade of brooding is unusual: normally it just throws it out. A misplaced snow flake can set it off. And it produces not…

The Ruminarian, again

By GeoLurking, January 8, 2014 (republished) Curmudgeon “an ill-tempered person full of stubborn ideas or opinions” Well, if the shoe fits, I guess I’ll wear it. But… I don’t come about it lightly. To me, stuff has to make sense. One thing I abhor is mindless ranting that is specifically intended to scare people. What…

Europe’s tallest volcano: Mount Elbrus

How can you hide a volcano? Apparently, making it the highest mountain on the continent is a good start. Mount Elbrus is both Europe’s tallest mountain and Europe’s highest working volcano. The first fact is commonly recognized, and can be readily found on-line and off-line, but the second fact is harder to locate. While Mont…

olcano? Erm... I don't see a volcano? Toba caldera wall seen from Samosir Island, a resurgent dome near the middle of the caldera. (Photo, Sebastian Hubarat, Tobaexplorer)

When Is a Caldera a Caldera?

Léon Prunelle / Originally published September 30, 2014 This is a re-post of an article by Henrik, written during the Bardarbunga eruption when the caldera had started its collapse. It does not take long for a newcomer to volcano-watching, if we are to call our hobby that, to come across the term “caldera”, cauldron. The term is…