VolcanicDegassing

Chile

Chaiten: anniversary of an eruption

Chaiten: anniversary of an eruption

May 1st marks the anniversary of the start of the first historical eruption of Chaiten, a small volcano in southern Chile, in 2008. A lot has been written on the eruption elsewhere, starting with Erik Klemetti’s eruptions blog which first reported on the event at the time. This is an opportunity to share some field photos, which I took during field visits to Chaiten in 2009. At the time of t ...[Read More]

Field report: Pumice

Field report: Pumice

One of the most rewarding parts of fieldwork on volcanoes is when the parts start to fit together, and hunches turn into firmer ideas. When piecing together ancient volcanic eruptions, the process often starts with the discovery of the trace of a new deposit in a road cut section. This might be something as simple as the appearance of a scruffy yellow or orange band that catches our eye as we pass ...[Read More]

Field report: beware of the sealions

Beware of the sealions (‘cuidado lobos marinos’) declares the sign at Valdivia fish market, which stretches along the docks in this southern Chilean city.  And it’s no joke either, as a large clan of these creatures has set up stall in the estuary beneath the fish market, ready to feast on the daily pickings cast over the sea rail. We are not here, however, to admire the sealife; or to ...[Read More]

Polygons, columns and joints

Over on her Georney‘s blog, Evelyn Mervine has recently posted a nice piece with some spectacular images of columnar jointing. This seemed like a good opportunity to dust off some field photos, with some more examples of polygonal joint sets in lavas from a variety of settings, to illustrate the diversity of forms that cooling-contraction joints may take in volcanic rocks. The first example ...[Read More]

Chilean volcanoes: shaken, but not always stirred?

November 7th marked the 175th anniversary of one of the largest earthquakes to have struck northern Patagonia. The earthquake, which is estimated to have had a magnitude of 8, had an epicentre close to Valdivia, and was accompanied by significant ground shaking and subsidence as far south as Chiloe island, and a major tsunami that reached Hawaii.  The eyewitness reports of the time have been well ...[Read More]