Question: what type of things do you do when you are a volcanic detective +what is it like ?

Philippa Demonte answered on 18 Jun 2011:

@chloelou98 I have very much been a volcano detective this week exploring Soufriere Hills Volcano here on the Caribbean island of Montserrat! On Tuesday i went with the other volcanologists to check on the monitoring equipment, including the cameras for the webcams, the electronic rain gauge (which can measure the size of rain drops and the speed with which they fall to calculate the amount of rainfall), the electronic tiltmeters (which measures the distance between sensors on either side of the volcano – if this distance increases, then we know the volcano is filling up with magma and therefore possibly going to erupt), etc. On Wednesday we went out to look for any clues that could tell us about the direction of the pyroclastic flows (flows of hot ash, gas, and rocks) that occurred last year so that we can forecast where any future eruption’s flows might go. The best clues were steel cables within concrete pillars of old houses as these were bent in the direction of flow. We also dug holes to look at how thick the flow deposits were, as this tells us something about the amount of material which was erupted by the volcano. On Thursday I worked in the rock lab looking at the different volcanic ash samples collected during the different eruptions. And yesterday (Friday) I did some computer work looking at satellite images to see where there are large boulders on the flanks of the volcano and how far they are from the lava dome. This tells us how powerful the lahars (mudflows) caused by rainwater + volcanic ash are.

One of the most important ways of monitoring a volcano though is to look at the seismic trace (squiggles on a recorder drum) of the mini earthquakes that a volcano makes. This tells us if magma or gas is rising, which is the first warning of a possible eruption.

You can find out more at http://www.mvo.ms/