Michael I. Bergman

Professor of Physics

at Simon's Rock since 1994


Contact Information

Courses, Fall 2010

Courses, Spring 2011

Research interests

Geophysical Fluid Dynamics:

The Earth's magnetic field is generated by fluid motions in the molten iron outer core, but the details of this magnetohydrodynamic (MHD) dynamo are poorly understood. However, rotational and magnetic forces are certainly important. Using a rotating table we built a laboratory model for the solidification of the Earth's core (picture). Solidification of the inner core from the outer core is thought to represent a primary energy source for the fluid motions that drive the geodynamo, so that understanding the convection that results from solidification may give insight into how the Earth's magnetic field is generated. One particularly interesting style of convection that occurs during solidification is channel convection (picture), which results from a non-linear focusing mechanism. In addition to possibly occurring at the Earth's inner-outer core boundary, channel convection occurs in solidifying sea ice sheets, where it plays an important role in the heat transfer between the atmosphere and the ocean, and in single crystal nickel-base alloys used in gas turbines, where it can be deleterious.

Mineral Physics:

When a melt solidifies, the crystallographic axes of the crystals may become aligned, resulting in what is known as a solidification texture. This texture affects a material's mechanical and electrical properties. Using a variety of materials such as sea ice and zinc-tin alloys we have been studying the effects of fluid flow (picture), annealing, and deformation on solidification textures. We have also been studying the ultrasonic properties of castings. The work is in part motivated by seismic inferences that the Earth's solid inner core exhibits a texture. We are exploring the possibility that this texture may in part be a result of fluid flow in the outer core during solidification of the inner core, or annealing and deformation after solidification. We are also interested in applications of this work to solidifying sea ice sheets in the Arctic and off Antartica (picture).

Selected publications