Event

The Department of Physics presents their seminar series with a PhD seminar by Dhanranjit Singh titled, An investigation into the role of gravity in tectonic plate motion under the supervision of Dr. Indra Haraksingh.

This event takes place at 1pm.

Abstract

The earth is layered with the various layers being the innermost inner core, outer core, lower mantle, upper mantle and outermost crust. The crust, together with the uppermost part of the upper mantle, is called the lithosphere. The lithosphere is relatively cool and rigid.

The lithosphere consists of separate blocks called tectonic plates. These plates are in constant motion, moving at speeds from about 1 cm/year to about 10 cm/year. It is generally thought that mantle convection is responsible for causing these tectonic plates to move. However, evidence of convection cells has never been observed and no one has been able to show the link between mantle convection and plate motion. There are other reasons for doubting that mantle convection is the main contributing agent for plate motion.

This study shows that the gravitational attraction between large masses such as tectonic plates plays a significant role in determining the motions of tectonic plates, including increases and decreases in speeds of different plates and the directions of their movements. This research specifically considered convergent plates that increase in speed and divergent plates that slow down. From calculated values of gravitational attraction and observed values of plate speeds, the coefficient of dynamic viscosity under the Indian and Australian plates was calculated and the results obtained agreed with values that have been experimentally determined.