Collaborative Research: Constraining Mantle Flow, Melt Supply, And Lower Crustal Structure Between The Clipperton And Siqueiros Fracture Zones From A Seismic Undershoot Experiment

University Of Washington, Seattle WA

Investigators

Abstract

A long-standing controversy in mid-ocean ridge dynamics is whether upwelling beneath fast spreading ridges is sheet-like with a relatively uniform magma supply along axis, or more three-dimensional with diapiric-like upwelling near segment centers and lateral redistribution of melt along axis at shallow magma chamber levels and/or by lower crustal, ductile flow. The UNDERSHOOT experiment was designed to address this problem by mapping the pattern of magma delivery from the mantle to the crust along the entire length of a transform bounded segment of the East Pacific Rise between the Siqueiros and Clipperton fracture zones. The quality of the data are the important issues that remain warrant further analyses. Models of crustal thickness will be refined by employing improved algorithms that allow all data collected in the experiment to be modeled simultaneously. Understanding of the properties of the Moho transition and uppermost mantle will be improved. Improved models of along axis variations in the structure of the mantle and lower crust low velocity zones will be developed.