Lithosphere and asthenospheric tomography and physical state mapping
1 June - 15 July 2023
Biography
Dr Schutt is a professor at Colorado State University. His research is focused on seismic structures in the earth’s upper mantle, and interpreting these in terms of temperature, composition, flow, and degree of melting. He is also interested in the tectonics of Canada, and has recently completed a field project in which he deployed 40 seismometers across the remote Mackenzie Mountains, in the Yukon and Northwest territories, including 500 km where there were no roads.
He is on sabbatical from the summer of 2023 to the summer of 2024, and hopes to focus on inferring the temperature of the tectonic plates during this time. One focus will be on the temperature around Greenland and Iceland. In Greenland, he hopes to constrain the heat flux into the base of the ice, which is critical for understanding glacial flow and the resulting sea level change. In Iceland, he hopes to figure out whether or not the hot mantle upwelling causing Iceland also has produced fingers of partially molten material that has extended as far as Scotland and Norway.
With Dr Wookey of the University of Bristol, he will also look at the temperature of Europe’s mantle, to best figure out the strength variations of the tectonic plates, which are important to understanding deformation, including mountain uplift and rifting.
When not doing research or teaching, Dr. Schutt is interested in hiking, backpacking, running, and spending time with his family.
Research summary
Estimates of the temperature and composition of the Earth’s upper mantle are essential for understanding how the earth circulates, and why and where the tectonic plates deform to create landforms such as mountain ranges and rifts. We can infer temperature and compositional variations from seismic velocities, which are determined as a function of depth in the Earth.
However, these estimates turn out to be very difficult to do, partially because rocks change their mineralogy with temperature and conventional methods do not capture the compositional complexity of the mantle. Recently, Dr Schutt has written software that will take calculated compositional variations and calculate the temperature based on observations of seismic velocities.
During the visit Dr Schutt and Dr Wookey plan to use this method to estimate the temperature of the tectonic plates. They will initially use Pn velocities, which is the velocity of a seismic wave that traves at the interface between the crust and the mantle. Dr Wookey will perform the velocity assessment, and interpret the models of velocity that are used, and then Dr. Schutt will use these to estimate the mantle’s temperature and composition. This information will then be used to understand the strength variations of the tectonic plates, which will shed light on the causes of deformation.
This approach aligns with research being undertaken by Dr Bob Myhill (School of Earth Sciences) to extend the methodology in Perple X and Burnman (a related code) under the auspices of a large NERC grant (MC2, Bristol PI Wookey) to study upwellings in the Earth’s mantle through a combination of geodynamics, mineral physics, and seismology.
We expect this research to be of interest for Mars seismology, as well as anyone interested in tectonic deformation of the upper mantle, and the interface between seismology and mineral physics.
Dr Schutt is hosted by Dr James Wookey in the School of Earth Sciences.
Planned activities include:
