Many problems in the Earth sciences involve fluid flow. Examples include the formation and subsequent thermal evolution of planets, the generation of planetary magnetic fields, the generation, rise, chemical differentiation and eruption of magmas, sedimentation and mechanical erosion at riverbeds, and circulation in the atmosphere and oceans. My research interests generally involve the application of experimental and theoretical fluid dynamics, combined with field- or laboratory-based observational studies to understanding the cooling and differentiation of planets. In particular, I am interested in constructing knowledge about how mantle convection leads to volcanism, and about how observations and modeling of volcanic processes can be applied to constrain the dynamics of planetary interiors.
Ten of the current questions in which I am interested include:
1) How do continents influence the nature and heat transfer properties of mantle convection?
2) What is the structure of the mantle plume underlying the Tharsis Rise on Mars? Did the emergence of this plume and associated production of the Tharsis volcanic province ultimately annihilate the early core dynamo?
3) Can climate change alter the tectonic style of terrestrial planets? How is this climate signal transmitted to the mantle? How does the mantle respond?
4) What are the processes that govern the sedimentation, stability, and ultimate longevity of explosive volcanic eruption columns and pyroclastic flows? What features of pyroclastic deposits might be used to infer the mechanics of such processes in prehistoric events?
5) How do basalt replenishments cause large crystal-rich silicic magma chambers to overturn and erupt catastrophically at the surface? How do we use observations from the geological record to constrain the key underlying processes governing these events?6) Why does the inferred strength of hotpsot volcanism vary spatially over the Earth's surface? What are the implications for the structure of mantle plumes? Why is the Hawaiian hotspot getting stronger?7) Why might partial melts occur and persist above the Earth's core-mantle boundary over geological time? What are the implications for the composition and thermal history of the mantle and the behaviour of Earth's core dynamo?
8) How do undersea eruptions and black smoker vents influence the chemistry and biodiversity of the deep ocean?
9) What is the origin of volcanic tremor that precedes explosive volcanism? Why is the character of this ground oscillation so consistent around the world?
10) What is the climatic footprint of a super continental cycle? How has the formation and destruction of supercontinents influence the evolution of Earth's atmosphere, ocean and biosphere?
Effective teaching is very important to me. My goal in the classroom is to create an environment in which knowledge is constructed by students more than it is presented by me. Said differently, I have found that an effective way €œto teach science€ is simply to do science in the classroom, with my role being mostly a coach. As an example of what I mean, think of how coffee in an insulated mug without a lid cools to the overlying air. To explain this problem in a class it is easy to envisage a series of lectures that would break the issue of how hot coffee cools down into the main components of the science of thermal convection. However, no matter how brilliant my explanations might be, it is infinitely more engaging and inspiring to simply place a drop of cream in the coffee and study how the motions driven by the surface cooling disperse the cream, and hence distribute the cooling over the full depth of the coffee. To illustrate my approach more formally, in the classroom we (the students and me) begin an analysis of the cup of coffee as a team. The first step is to describe in detail everything we can observe about the cup, the coffee, and the drop of cream. Next, we formulate questions aimed at deciphering the driving dynamics of the cooling problem. These questions lead, in turn, to further inquiries about the physics of the problem that could take us first to textbooks and then to research articles. Following a careful study of the physics of the problem we would formulate hypotheses designed to unravel in a clear way precisely how the coffee cools. To test these hypotheses we would develop a list of good experiments to do and then we would do them. At the end of this study the students would have learned the significance of the scientific method, how to formulate and solve problems and, ultimately, how to construct knowledge in small and careful increments—i.e. learn.