History of Öræfajökull

Iceland has ice. Glaciers cover 10% of its landscape, including its highest volcanoes. Of its frequent eruptors, only Hekla is (almost) ice free. Katla, Bardarbunga, and Grimsvötn, which together account for the large majority of eruptions, are all hidden underneath ice sheets, which gives problems studying the volcanoes themselves. But a more serious issue is…

Krakatoa: a blast from the past

Note: For a blog post on Mount Agung, see http://big-volcanic.com/agung-volcano-nearing-an-eruption-here-is-what-to-expect-from-the-bali-volcano/ This is a repost, originally written in 2015. Small edits have been made, and some new (old) images added. It is one of the most famous volcanic eruptions in history. The loudest explosions ever recorded, dust spreading worldwide affecting sunsets for years, and it occured…

Failure

The signs were unequivocal. It started with earthquake swarms. A phreatic eruption followed, and than the ground began to swell. Magma was approaching the surface. An eruption was on the cards and evacuation plans were put in place. An exclusion zone kept people safe but not their possessions – and as always some people could…

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…

Iceland in motion

Imagine an Atlantic island affected by a deep and complex rift, with half the country pulled east, towards Europe, and half pulled west, leaning towards America, but the northern part actually feeling closer to Scandinavia whilst the southern half doesn’t know where it is going. The rifting causes frequent eruptions with significant financial consequences. Its…

The Strangest Volcanoes In The World – A Non-Official List

This cbus05 classic was published in 2014, during the height of Holuhraun. It is well worth re-reading, and so we are very happy to give it a rerun. And we are equally happy to commend his Big-Volcanic.com blog to you! In light of the extremely unique and interesting events going on at Vatnajökull, it’s interesting…

Up!

When the ground starts to rise beneath your feet, it is time to sit up. Fishermen would be the first to notice, being unable to leave their harbours due to lack of sea. Governments would discuss the risk of reduction in tax income from fishing, and would commission research. The scientists report evidence of widespread…

Ice age

The signs are everywhere. In some places, huge stones are found lying on the land, in a place where no rock exists. In other places, deep scratches in the stony surface, all pointing in one direction. U-shaped valleys are found in hills, a shape which rivers don’t do. To the readers of the landscape, it…

Volcanohistology: when eruptions make a difference

Volcanoes are frightening. They can dramatically alter the local landscape, and change people’s live – normally for the worse. The best place to be is far away. But large eruptions can have wider impacts. The ash can cover regions a continent away, and sulphate aerosols can spread at high altitude around the world. The sulphate…

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…