How does the Earth`s crust grow at divergent plate boundaries? A unique opportunity in Afar, Ethiopia

Abstract

We have acquired high quality magnetotelluric (MT) and TEM (for static shift correction) data along a 50 km profile perpendicular to an active magmatic centre in Afar, Ethiopia. After robust processing, dimensionality and geoelectrical strike direction assessment, static shift correction and rotation into geoelectrical strike co-ordinates, the MT data have been inverted for a 2D model of resistivity beneath the profile, with a minimum misfit of 1.8. This model has a near surface conductor, interpreted as a sedimentary layer containing large quantities of saline fluid in the shallow sub-surface, and a deeper (lower crust/upper mantle) conductive zone, interpreted as a magma chamber or zone with significant partial melt. The data are being interpreted in conjunction with other geophysical, geological and remote sensing data to understand the processes associated with continental rupture.