GeoLog

volcanology

Imaggeo on Mondays: Mount Bromo – volcanic deity

Imaggeo on Mondays: Mount Bromo – volcanic deity

Featured in this photo, rising out from a sea of violet fog at dawn, is one of Indonesia’s most iconic volcanoes, Mount Bromo. The mountain is a large volcanic crater, also known as a caldera, which formed when an ancient cone volcano collapsed in the late Pleistocene and early Holocene epochs, between 126,000 and 8,300 …[Read More]

Iceland’s rootless volcanoes

Iceland’s rootless volcanoes

Picture a volcano, like the one you learned about in primary school. Can you see it? Is it a big rocky mountain, perhaps with a bubbling pool of lava at the top? Is it perched above a chasm of subterranean molten rock? I bet you didn’t picture this: You’d be forgiven for mistaking these small …[Read More]

Imaggeo on Mondays: Hints of an eruption

Imaggeo on Mondays: Hints of an eruption

The photograph shows water that accumulated in a depression on the ice surface of Vatnajökull glacier in southeastern Iceland. This 700m wide and 30m deep depression [1], scientifically called an ‘ice cauldron’, is surrounded by circular crevasses on the ice surface and is located on the glacier tongue Dyngjujökull, an outlet glacier of Vatnajökull. The …[Read More]

Imaggeo on Mondays: Breath from the underground

Imaggeo on Mondays: Breath from the underground

The heat seeping from the geothermal area which is part of the Krafla volcanic system in Iceland, ‘powers’ the steaming vent at Hverir (Hverarönd). The area is well known for its mud pots and sulphuric gas fumaroles, complete with pungent eggy smell. Some of the vents are in fact boreholes drilled in the 50’s for …[Read More]

Imaggeo on Mondays: A lava layer cake

Imaggeo on Mondays: A lava layer cake

Brekkuselslækur, a small river, carves its way across Iceland’s ancient volcanic landscape. At Hengifoss, Iceland’s third-highest waterfall, it tumbles fiercely down thick, dark layers of lavas erupted from volcanoes some 18 to 2.58 million years ago, during a period of geological time known as the Tertiary. Eruptions are rarely continuous; during hiatuses in the extrusion …[Read More]

Imaggeo on Mondays: In the belly of the beast

Imaggeo on Mondays: In the belly of the beast

Conducting research inside a volcanic crater is a pretty amazing scientific opportunity, but calling that crater home for a week might just be a volcanologist’s dream come true, as Alexandra postdoctoral researcher at the Institut de Physique du Globe de Strasbourg, describes in this week’s Imaggeo on Mondays. This picture was taken from inside the …[Read More]