For as long as I can remember I’ve always been curious about how things work, which ultimately motivated me to study physics in University. Combined with a love and enjoyment of our natural world, I specialised in geophysics, which involves using instruments placed on the surface to image within the Earth. I now use a technique called magnetotellurics (or just MT for short!) which allows imaging fluids and melt to depths of 10 km or more. As they say ‘if you’re having trouble with the plumbing, it’s good to know where the pipes are’, and being able to image fluids and melt in the Earth is clearly beneficial to understanding how volcanic and geothermal systems work.
Particularly enjoyable are the remote locations that I’ve experienced while undertaking MT surveys across Canada, USA, Taiwan, NZ, Antarctica and Japan. However, the most satisfying part of my work is integrating with others and communicating new results. The cherry on top is learning how results I’ve achieved have been used by others in a practical sense (e.g. geothermal exploration or management) or by colleagues to advance additional research.
Bertrand, E.A.; Caldwell, T.G.;Hill, G.J.; Wallin, E.L.; Bennie, S.L.; Cozens, N.; Onacha, S.A.; Ryan, G.A.;Walter, C.; Zaino, A.; Wameyo, P.; 2012, Magnetotelluric imaging of upper-crustal convection plumes beneath the Taupo Volcanic Zone, New Zealand, Geophysical Research Letters, 39(2),L02304, doi:10.1029/2011GL050177
What was the research finding?
An array of 200 MT measurements was used to provide the first-ever images of connections between the shallow geothermal fields in the Taupo Volcanic Zone and their underlying magmatic heat sources that drive convection in the brittle crust.
Why is it important?
While this paper (and others that have followed) support the long-held model of convective heat transport in the TVZ, variation in the crustal resistivity structure observed beneath different geothermal systems showed that magmatic intrusion and basement structure (tectonic and volcanic) are more important influences than previously realised. These models and others have informed subsequent geothermal exploration in the TVZ and are used by regional councils to support their sustainable management of these systems.
Where are you?
At an MT site, somewhere in the Southern Alps of NewZealand.
What are you doing?
MT is a great combination of high-tech and low-tech. We have to bury our sensors so they are aligned and don’t move during recording, which involves a fair bit of digging! It’s great exercise and if ever needed I could probably have an alternate career installing fence posts.
Read more about Ted's experience here.