Shear-wave splitting Tomography At Kilauea

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Kilauea volcano, in Hawaii, is one of the most active volcanoes in the world. Since 2008, there has been an eruptive vent at the summit of the volcano, with a lava lake. Further down the volcano, there has been another vent erupting lava since 1985. In April 2018, magma supply stopped at these two places, and travelled under the ground to the residential region of Puna, where it erupted in 24 different fissures. Over 2000 people have been evacuated from their homes and up to 700 buildings have been destroyed by lava flows. The last time there was an eruption in this area was 1960.When magma pushes its way through the rock, it causes lots of small earthquakes. Earthquake waves can be polarised in a similar way to the way light is polarised. Rock polarises earthquake waves when it is under pressure and tiny cracks line up in one direction. This causes earthquake waves to travel faster in one direction (along the cracks) than the other (across the cracks). Therefore, we can use the polarisation of the earthquake waves to understand how the rock gets pressurised as the magma travels through it.This new eruptive activity at Kilauea means that we can investigate areas that we previously couldn't because there were not enough earthquakes. We will set up four new stations to measure the new earthquakes and use data from the existing monitoring network. We will use the new earthquakes to make images of the pressure in the rocks during this eruption and will be able to see what happens to the pressure when the eruption stops. This information will be useful to understand the eruptive behaviour of Kilauea, will help monitoring and forecasting changes in eruptive activity, and will also be applied to other volcanic systems around the world. To do this, we have made a team of excellent researchers from the University of East Anglia and the US Geological Survey.