skip to primary navigationskip to content
 

E410: Seismic attenuation tomography of Iceland (Lead Supervisor: Bob White, Earth Sciences)

Supervisors: Bob White (Earth Sciences) and Nick Rawlinson (Earth Sciences

Importance of the area of research:

The measurement of seismic attenuation (energy loss during wave propagation) in the crust and upper mantle provides valuable information on composition and physical state; for example, in volcanic regions where hot molten material percolates through the crust and can form magmatic reservoirs, attenuation can be extremely high due to the presence of melt and elevated temperatures. It is possible to build 3-D images of the attenuation structure beneath the Earth's surface  using a technique called seismic tomography, in which waveforms generated by a large number of sources and recorded by an array of receivers. Iceland represents an ideal location in which to apply such a method, because it lies at a mid-ocean ridge and is underlain by a mantle plume, which together produce widespread volcanism and igneous intrusions. This project will be the first attempt to image the attenuation structure beneath Iceland in detail using local and regional earthquake data.

Project summary:

The aim of the project is to apply seismic attenuation tomography to our world-class dataset from Iceland, which extends back two decades. Particular target areas will include the plumbing systems beneath recently active volcanoes, such as those found in the Northern Volcanic Zone. For example, the Askja volcanic system, which last experienced an eruption as recently as 1961,  is one of the largest volcanic systems in Iceland, yet we have only recently begun to understand its internal structure and dynamics. Recent traveltime tomography images reveal the likely presence of multiple melt storage regions beneath the volcanic system, something which can be readily detected using attenuation tomography.

What the student will do:

The student will be involved with fieldwork servicing our broad-band seismometer array in central Iceland (currently with 29 instruments), then integrating new data with our catalogue of seismic data in the region which extends back to 2007. They will then apply seismic attenuation tomography to the data using techniques developed by the supervisors. This will be done across multiple scales, from the volcanic to the entire Iceland region.  Many of the computer programs for the analysis already exist, though it is likely that the student will want to develop some of these for their own analysis.  If time allows, the student will also be able to apply the techniques developed with the Iceland dataset to a new dataset collected from North Borneo, which recently experienced collisional orogeny and the termination of active subduction.

Please contact the lead supervisor directly for further information relating to what the successful applicant will be expected to do, training to be provided, and any specific educational background requirements.

References:

Ágústsdóttir, T., Woods, J., Greenfield, T., Green, R. G., White, R. S., Winder, T., Brandsdóttir, B., Steinthórsson, S. & Soosalu, H.  2016. Strike-slip faulting during the 2014 Bárðarbunga-Holuhraun dike Intrusion, central Iceland. Geophysical Re

Greenfield, T., White, R. S. & Roecker, S 2016. The magmatic plumbing system of the Askja central volcano, Iceland as imaged by seismic tomography, Journal of Geophysical Research, 121, doi: 10.1002/2016JB013163.

Rawlinson, N. Pozgay, S. & Fishwick, S. 2010. Seismic tomography: A window into deep Earth. Physics of the Earth and Planetary Interiors, 178, pp. 101-135.

Follow this link to find out about applying for this project.

Other projects available from the Lead Supervisor can be viewed here.

Filed under: