Mapping the geothermal anomaly on the island of Milos by magnetotellurics

Audiomagnetotelluric and magnetotelluric measurements have been performed on the island of Milos. Importance was attached to robust processing techniques and to the distortion problem at longer periods. The geothermal anomaly displays extremely low resistivities (0.2 ohm.m) at 10 Hz, which corresponds to the upper 200 m. The central anomaly is still seen at periods around 1000 s. The joint mapping of apparent resistivity P ∗ by all groups participating in the experiment indicates the detailed outlines of the anomaly.