GP23C-07
Sensitivity of an MT Array to 3D Structure Outside the Array Footprint

Tuesday, 15 December 2015: 14:55
300 (Moscone South)
John R Booker1, Randall L Mackie2, Aurora I Burd1, Maria C Pomposiello3 and Alicia B Favetto3, (1)University of Washington, Seattle, WA, United States, (2)CGG United States Houston, Houston, TX, United States, (3)Institute of Geochronology and Isotropic Geology, Buenos Aires, Argentina
Abstract:
Standard data collection strategy in magnetotellurics (MT) is to deploy a profile or array of sites that spans the target of interest. There is no expectation that structure can be imaged outside the area covered by sites. We have inverted two MT arrays for 3D structure under Argentina. The two arrays do not overlap, but serendipitously the 3D model for the northern array overlaps the position of a prominent 3D deep conductive structure seen in the inversion of the southern array. To our surprise this deep southern feature is also imaged by the northern array even though it is well outside the footprint of the northern array. It therefore appears that typical intuition about one's ability to image structure outside the span of the sites is not always true. We present model studies to demonstrate why this is so and under what conditions one can expect a 3D array to be capable of imaging structure outside the array.