Revealing the Hikurangi Subduction Zone with Joint Sparse OBN and Streamer FWI

Abstract

AbstractFull-waveform inversion (FWI) utilizing long-offset ocean bottom node (OBN) data has become a key velocity model building tool for resolving complex velocities for deeper targets. Acquiring such OBN datasets with dense shot and receiver sampling remains costly. Sparse OBN data has been studied in recent years to reduce acquisition expense while maintaining desired benefits for FWI. Whereas sparse OBN data can provide velocities comparable to dense OBN data, it alone cannot provide seismic images and gathers fit for interpretation purposes. We demonstrate a cost-effective approach using joint sparse OBN and streamer FWI that effectively updates the deep velocity of a complex subduction zone in the Hikurangi margin near New Zealand's East Coast. The streamer data is then migrated to provide detailed and accurate images fit for interpretation.