He has made numerous contributions to the study of Earth's mantle, continental structure and evolution using seismic tomography, [3][4][5][6] the analysis of sea level change in the Last Interglacial[7][8] and of ice sheet mass variations though the Gravity Recovery and Climate Experiment,[9][10] and to the theory of spatiospectral localization via prolate spheroidal wave functions.
[11][12][13] Simons is involved in the design of marine instrumentation for recording earthquakes, specifically iterations of MERMAID.
Simons earned his Bachelor's and Master's of Science from KU Leuven in 1996, and his Ph.D. in Geophysics at Massachusetts Institute of Technology (MIT) in 2002.
A well-known example is the MERMAID (Mobile Earthquake Recording in Marine Areas by Independent Divers) instrument, a passively drifting autonomous mid-column hydrophone.
The idea of collecting earthquake data for global tomography by robotic drifters is credited to Guust Nolet, a Princeton Professor of geophysics emeritus, who was Simons' postdoctoral advisor.