The PIs will deploy an autonomous underwater hydrophone (AUH) network in conjunction with OBSs in the Lau Basin. Since T-wave generation processes are not well understood the PIs will use the AUH and the OBSs to compare and establish how to integrate the datasets, allowing them to constrain the tectonics of the region and monitor both earthquake activity and volcanism. The comparison will allow future hydrophone data to be used to extract quantitative information regarding earthquake source parameters and processes. Broader impacts include collecting both the seismically-generated signals and whale songs which will be used in the proposed development of a K-12 curriculum module that includes the building of a hydrophone. There is also graduate and undergraduate student participation and continued public outreach by the PIs at local, national, and international levels.