Amplitude Variation with Offset Studies and Pre-stack Imaging of the ARAD 3-D Reflectivity Volume

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The Anatomy of a Ridge Axis Discontinuity (ARAD) 3-D seismic experiment is a cooperative experiment between Scripps Institution of Oceanography and Cambridge University. The field experiment was conducted aboard the R/V Ewing in Septemer-October 1997 and was located over the 9 degrees north overlapping spreading center on the East Pacific Rise. Key elements of this experiment included the first 3-D reflection survey of a mid-ocean spreading center and a coincident 3-D crustal tomography experiment. Preliminary data analysis suggests that the observed distribution of crustal magma accumulations beneath the overlapping spreading enter appear to be inconsistent with either a simple, broadly symmetrical structure or with models which depict the lims at attenuated ends of magmatic systems fed largely y horizontal flow. Instead the magma seems to be fed from directly eneath the offset basin. Further analyses are planned during the period of this grant.