GeoLog

Geochemistry, Mineralogy, Petrology & Volcanology

Imaggeo on Mondays: Mammoth structures, springs and snowmelt

Spring waters are rich in minerals, carrying with them dissolved components of the rocks they have travelled through. The water that discharges at Mammoth Hot Springs in Yellowstone National Park is highly alkaline (contains a lot of dissolved CO2) and rich in calcium, but as the water cools, the calcium precipitates to form the white limestone terraces you see here. This limestone is known as tra ...[Read More]

Introducing the new EGU Bloggers!

Since it started, the EGU Blog Network has had great coverage of geochemistry, palaeontology and geoscience in global development, but what about the other fields in the geosciences? Well, over the past couple of months we’ve been seeking out some fantastic Earth science bloggers who are keen to share their knowledge, experiences and the latest research in their fields with you. They’ve put togeth ...[Read More]

Imaggeo on Mondays: Capping a volcano

This is Damavand Volcano, Iran. Its history is one of short bursts of eruptive activity followed by long periods of quiescence and while there are active fumaroles near Damavand’s summit, the volcano has been dormant for the past 1000 years. The cloud that encircles its peak is known as a cap cloud, so-called because these peculiar clouds form around high peaks, adding a flat white cap to mountain ...[Read More]

Geosciences Column: Tracing Toba

Large volcanic eruptions have a significant impact on the Earth’s climate as aerosols (including sulphur dioxide and water vapour), together with ash are released into the atmosphere and increase the amount of sunlight reflected back into space (the albedo). This increase in reflectance (or decrease in energy absorption) can cause widespread climatic cooling, known as a ‘volcanic winter’. However, ...[Read More]