Meet the scientists!

I have been studying geology, maths, physics and computer programming for the past 3 years. Using cool gadgets such as seismometers and satellites, geophysicists like me are able to explore the inside of the Earth without going underground.

At university I have been learning about what causes earthquakes and tsunamis, how the flow of heat from the Earth’s core generates a magnetic field which protects our planet from harmful cosmic rays, and why you are more likely to feel the effects of gravity at the North and South Pole than at the equator.

My main interest though is volcanoes. Did you know that whilst you are reading this, about 20 volcanoes are erupting right now? More volcanoes will erupt in the future, and each one behaves differently. I am part of a group of scientists trying to find the answers to questions such as: ‘When, where, and how will the next volcano erupt?’, ‘How big will the eruption be?’, ‘How long will it erupt for?’, ‘Will the volcano only erupt once or more than once?’, ‘How many people will it affect? Where? For how long?’, ‘How long will it be before the volcano erupts again?’, ‘What clues from the volcano’s past will help us to forecast its future activity?’,…and so on. I guess you could call me a volcano detective.

An example of a ‘typical’ day whilst I’ve been at university: using computer programmes to work out the locations of earthquakes; looking at thin-sections of rocks through a microscope to work out how the rocks were made; spending a few hours in the library reading about research by other scientists….My favourite days are those spent outdoors playing with the geophysics gadgets.

I have just started working at Montserrat Volcano Observatory where scientists are responsible for monitoring an active volcano in the Caribbean called Soufriere Hills volcano. I did something different every day for my first week.

On Monday one of the other scientists, Mel, drove me around Montserrat to show me some of the volcanic features including lahar deposits in Belham valley …and pyroclastic flow deposits which went into the sea on the east of the island creating new land. Pyroclastic flows are made up of hot volcanic ash, rocks, and gases; they flow faster than a car can drive, and they can flow both uphill, downhill, and across water, making them very dangerous. Lahars are mudflows which occur when heavy rainfall washes the loose ash deposits off the sides of the volcano.

On Tuesday I went with the volcanologists to check some of the monitoring equipment. This included changing the photo cards for the Montserrat Volcano Observatory webcam, checking the weather stations which measure wind speed, wind direction, etc (the observatory needs to know which way volcanic gases and the ash plume will be blown), and checking that one of the reflectors for the tiltmeter was pointing in the right direction. There is another reflector on an opposite hill. The tiltmeter measures the distance between the 2 reflectors. If this distance increases from the normal distance, this tells us that the sides of the volcano are expanding and that new magma is going into the volcano from deep below.

In this photo the metal triangular shaped object is the reflector. In front of this you can also see the rain gauge which measures both the speed and the size of rain drops as they fall between the sensors. Heavy rainfall can trigger lahars or even a volcanic explosions as the cold water mixes with hot magma/lava.

On Wednesday we went by helicopter to another part of the exclusion zone on the other side of the volcano to look for clues which would tell us about the direction of the pyroclastic flows from last year’s eruption. Old, abandonned houses in the exclusion zone give us the best clues. For example, in this image you can see that the metal window frame has been twisted and pushed out towards us, which means that this is the way the pyroclastic flow went – through the house! We can then use a compass to measure this direction in degrees from North.

We also dug some holes to see how deep each ash layer was and what size the rock grain particles were. You can see in this image that the different ash layers are different colours, and you can feel the difference in the grain sizes by running your finger over them. These measurements help the volcanologists to estimate how much material was erupted each time by the volcano.  

We were only working 2-3 km away from the active dome of the volcano on Wednesday, so we had to wear special clothing which would give us some protection if the volcano were to erupt: hiking boots …and orange heatproof overalls, plus we also had helmets, heatproof gloves and gas masks with us.

I spent Thursday working in the rock laboratory at the volcano observatory. After each volcanic eruption samples of the ash fall are collected from around the island, for example from rooftops of buildings. These can then be analysed to look at the size, shape and type of the ash fragments, and this then tells us something about how explosive each eruption was. If we know where on the island the samples were taken from, we can then also do a map to show which parts of the ash cloud fell where in order to calculate roughly how high in the sky the volcanic plume went.

On Friday I did some computer work using aerial images (photos taken by a satellite or from a plane looking down at the ground) to look at where big volcanic boulders are on the ground. I used the computer programme to measure roughly how big they are. Using the computer and the photos  means that I don’t have to go to the actual location to take all these measurements which would be a) take too long, and b) be too dangerous! This form of science is known as remote sensing.