Beautiful Lake Taupo, New Zealand. The only hint of its volcanic origin are the distant volcanoes on the horizon, built at the edges of the ring fault system. (Provenance unknown)

When Is a Caldera a Caldera?

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 very loosely used to describe large volcanic depressions ranging from volcanic craters a few hundred metres in diameter up to the huge depressions left behind by the…

Koko Crater, Hanauma Bay and Hawaii Kai. Image from Wikipedia (by Mbz1, CC-BY-SA-2.5).

The Volcanic Landmarks of Oahu, Hawaii – The Conclusion

Hanauma Crater The Hanauma Crater was created during the Honolulu volcano series. The volcanic vents that formed Hanauma Crater opened on the seafloor about 32,000 years ago. Upwelling magma vaporized the ocean water and steam explosions atomized the magma into fine ash. The explosions built cones of ash, which solidified into tuff. The eruptions shattered the coral…

Crater Lake oregon. Image Wikimedia Commons

Volcano – a mountain that spits fire? Volcano basics part 2

How do the insides of a volcano look like? Most volcanoes form a cone, as you can see in the graphics above. During an eruption the volcano flings out material which builds up, layer upon layer, and often forms this form of landscape. There are different types of cones: stratocones, spatter cones, ash cones, tuff cones, and cinder cones. What a volcano…

Etnas paroxysm no 20 as dawn breaks.

Eruption updates on Nishinoshima and Etna

Nijima The little Island of Nijima next to Nishinoshima Island on the Nishinoshima Seamount is steadily growing and is now around 400 by 250 meters. Previously the main growth have been away from the island of Nishinoshima so it looked kind of dubious that the islands would merge during this eruption. Now there is though…