Some attempts have been made with additional geophysical techniques but no breakthrough was yet achieved. Thus the established methods still constitute the dominant part of volcanological research. The high resistivity contrasts on volcanoes suggest the application of electromagnetic methods for structural investigation and monitoring purposes. The contrast is generated by the characteristics of the mostly cold, dry and resistive hostrock and the hot, wet and conductive magma reservoir and its associated hydrothermal system. The Merapi project Scientists from Indonesia, France, the US and Germany work on Mt. Merapi.
Geological projects work on magma evolution and eruption history.
For this method electrical currents are injected by a powerful transmitter into the ground. From the recorded data we can derive the resistivity distribution of the interior of the earth. These resistivities can be associated to different kind of rocks, fluid content and temperature. Molten rock has a very low resistivity, the cold dry hostrock a high resistivity. The depth and extend of the magma reservoir can be derived afterwards by combining the electromagnetic results with the results of the other geophysical methods.