WAVES OF THE FUTURE - SUPERIOR INFERENCES FROM COLLOCATED SEISMIC ANDELECTROMAGNETIC EXPERIMENTS

The advent of high-quality seismological studies of the Earth's contin ental lithosphere has been paralleled by an explosion in both the qual ity and quantity of concomitant high-resolution electromagnetic studie s. The latter were inspired by technological and intellectual advances during the last decade in the acquisition, processing, modelling and inversion of particularly natural-source magnetotelluric (MT) data. Th e complementary nature of seismics and MT leads to rejection of hypoth eses that may be tenable if only one of them is applied. Equally, infe rences supported by both have stronger conviction. Perhaps most useful is when apparent incompatibilities must be reconciled by re-examinati on of both datasets. This is demonstrated through examples of magnetot elluric and seismic reflection studies undertaken in the last decade i n many tectonic environs, from Palaeoproterozoic collision zones to pa ssive margins to active collision zones. Some aspects of MT are explai ned, particularly the method's sensitivity and resolution of geoelectr ic directionality and dimensionality. New directions are proposed wher eby greater utility of the joint datasets can occur, both at the outse t during data acquisition, and in the interpretation phase in modellin g and inversion. Also, laboratory measurements of seismic, electrical and rheological properties of the same rock sample will make integrate d interpretation more tenable. (C) 1998 Elsevier Science B.V. All righ ts reserved.