Congratulations to Ross Maguire who defended his dissertation on April 6, 2018

Advisor: Jeroen Ritsema

Abstract:

The leading hypothesis for the origin of 'hotspot' volcanism in locations such as Hawaii and Iceland is thermal upwellings (i.e., 'plumes') rising from the lower mantle. Key evidence comes from seismic images of low wave speed structures in the deep mantle below hotspots, which are often interpreted as hot plume tails. However, imaging results are often ambiguous and it is questionable whether plume tails can be detected by present-day seismological techniques. Using geodynamic and seismic modeling, and mineral-physics relationships between temperature and wave speed I have investigated how much plumes decelerate seismic waves and how plumes are expected to be imaged by seismologists.The results improve our understanding of how to interpret seismic anomalies below hotspots, and help guide the design of future seismic experiments.