An integrated observational, experimental and computational study of plume-ridge interaction

The existence of sub-horizontal channels connecting hotspot plumes and spreading ridges has been suggested by recent observationally based studies. These features have important consequences for understanding mantle dynamics and the manner in which the mantle interacts both thermally and chemically with Earth`s surface. A striking result has been the importance of a sloping rheological boundary layer, resulting from the combination of variable fluid viscosity and plate spreading, in modulating channel development and evolution. Comparison of results in 2D and 3D experiments clearly indicate the limitations of 2D representations of flows which include both small scale plumes within a larger scale shear flow. 2D experiments investigate higher order physical effects such as thermochemical plumes and relative motion between plume source and ridge axis. These effects are best studied first in the more simplified 2D geometry. Experiments completed to date have significantly increased our understanding of the process of communication between plumes and ridges. This initial stage of funded research has also lead to increased interaction between observation and theory. As an example of this, Kincaid was invited to participate in a data collection cruise to Easter Island-EPR system designed to study plume-ridge interaction