Deep crustal studies in Antarctica using wide band magnetotelluric method

Complete text of publication follows. To map the deep electrical conductivity structure of East Antarctica around Maitri, the Indian permanent station, long period MT studies have been taken up using wide band (1000-0.001 Hz) including short and long period signals covering both AMT and MT signals. A total of six stations have been occupied with a station interval of 3-4 km during January - February 2006. The stations are occupied along a profile oriented in a NE-SW direction. One station occupied near Maitri station on land and remaining five stations are on continental ice sheet area. The MT data have been collected for about 5 days at each station to acquire long period signals and also to obtain good quality of short period signals. Use of titanium electrodes as e-probes has reduced the contact resistance further to kilo-ohms and facilitated to record the high frequency signals. In the present study, results are presented in the form of a deep crustal geoelectric section. From 2-D modeling along NE-SW profile, it is observed a high resistive (104 ohm.m) upper crust upto a depth of about 10 km and mid and lower crustal thickness of about 25-30 km. Relatively resistive (>102 ohm.m) upper mantle is obtained. The crustal structure is compared with south Indian shield region.