GeoLog

Geochemistry, Mineralogy, Petrology & Volcanology

Imaggeo on Mondays: Finger Rock

April 27, 2015
Finger
Finger Rock. Credit: Dmitry Demezhko (distributed via imaggeo.egu.eu)

Standing proud amongst the calm waters of Golovnina Bay is ‘The Devil’s Finger’, a sea stack composed of volcanic sediments. Located on the Pacific coast of Kunashir Island -which is controlled by Russia but claimed by Japan – the stack is testament to the volcanic nature of the region. The island itself is formed of four active volcanoes which are joined together by low-lying geothermally active ...[Read More]

GeoTalk: Explosive testing with Greg Valentine

April 16, 2015
GeoTalk: Explosive testing with Greg Valentine
The Eastern Ukinrek Maar, Alaska. Credit: R. Russell, Alaska Department of Fish and Game, USGS.

Following his session at the EGU General Assembly, Greg Valentine (Buffalo University) spoke to Sara Mynott about how he creates model volcanoes, specifically maar-diatremes, and blows them up to better understand what goes on in an eruption… So what is a maar-diatreme? A diatreme is a vent-like structure, mostly made up of broken up bedrock and magma. Initially, you have a dyke that channels magm ...[Read More]

Imaggeo on Mondays: Pyroclastic flow, Montserrat

March 9, 2015

Below the warm and tranquil waters of the Caribbean, some 480 km away from Puerto Rico, the North America Plate is being subducted under the Caribbean Plate. This has led to the formation of the Lesser Antilles volcanic arc; the result of the formation of reservoirs of magma as fluids from the down going North America Plate are mixed with the rocks of the overlying Caribbean Plate. The continued m ...[Read More]

Imaggeo on Mondays: An explosive cloud

February 23, 2015
Imaggeo on Mondays: An explosive cloud
Karymsky volcano, 2004. Credit: Alexander Belousov (distributed via imaggeo.egu.eu)

One of the world’s most volcanically active regions is the Kamchatka Peninsula in eastern Russia. It is the subduction of the Pacific Plate under the Okhotsk microplate (belonging to the large North America Plate) which drives the volcanic and seismic hazard in this remote area. The surface expression of the subduction zone is the 2100 km long Kuril-Kamchatka volcanic arc: a chain of volcanic isla ...[Read More]