Richard J. O'Connell
Professor of Geophysics
The central aim of my research is to understand the internal dynamics of the Earth and how they influence geological events
on the surface and the evolution of the Earth over geologic time. Even though it is widely acknowledged that thermal convection
in the Earth's mantle is the cause of lithospheric plate motions and the tectonics associated with plate interactions, the details
of the processes and how they have operated over Earth history are still unclear in many cases. Our work has focussed on constructing
models of such processes in order to better understand how they operate and how they influence phenomena that can be observed.
Over the last several years, we have developed models of mantle convection in 3 dimensions that allows for the presence of lithospheric
plates on the surface. We have also studied models of subduction and how it develops with time as well as how subduction influences lithospheric
deformation and mountain building. Models of global flow in the mantle over the last 100 My have been used to study the distribution and motion
of hotspots, and how these may influence determinations of plate motion. Similar models can predict polar motion that agrees well with the paleomagnetic
record over the past 80 My. The models have been used to calculate strain in the mantle that causes seismic anisotropy, and stress in the lithosphere.
We are also pursuing work related to understanding geochemical evidence for heterogeneity and distinct geochemical reservoirs in the mantle.
I also have a long-standing interest in the elastic and anelastic properties of rocks in the crust and mantle, and how they relate to seismic
observations and geodynamic processes. For more details please follow the link to Research.
Earth & Planetary Sci 161: Planetary Physics and Global Tectonics
Earth & Planetary Sci 201: Physics of the Earth's Interior
Earth & Planetary Sci 260: Topics in Geophysics
Earth & Planetary Sci 265r: Topics in Geodynamics
For up-to-date information on these classes visit the registrar's website.
Room 101, Hoffman Building
tel:+1 617 495-2532 (Voice)
email: richard_oconnell (at) harvard (dot) edu