by Friedemann Samrock, Alexander V. Grayver, Hjalmar Eysteinsson, Martin O. Saar. First published: 28 November 2018 Geophysical Research Letters, https://doi.org/10.1029/2018GL080333
The Earth's continental plates can be broken apart by tectonic forces to form rift systems that may extend over thousands of kilometers. Continental rifts are often associated with numerous volcanoes that are fed by magma, which forms deep in the Earth's mantle and rises up along pathways of the fractured tectonic plate. A detailed understanding of the volcanic systems is important for hazard assessment and for geothermal energy production.
We analyzed geophysical data that were measured at a volcanic field in the Ethiopian Rift Valley. The data consist of time series of the natural electric and magnetic fields. These fields are sensitive to the electrical conductivity structure of the Earth and can be used to image the subsurface electrical properties down to depths of many kilometers. Magma, for example, has typically very high electrical conductivities, which is why this method is ideal to detect melt reservoirs in the Earth's crust.
Our obtained model shows, in great detail, how magma is transported through the crust and how it is stored below the volcanic system. Therefore, it provides new insights into rift‐associated volcanism, risk assessment, and geothermal energy production.
