Collaborative Research: The Thermal Regime of the Hikurangi Subduction Zone and Shallow Slow Slip Events, New Zealand

Oregon State University, Corvallis OR

Investigators

Abstract

Heat flow and seismic reflection data will be collected offshore the northern and southern Hikurangi margin in New Zealand, to develop a process-based understanding of the thermal structure of the subduction zone. The northern area is underlain by an aseismic creep-dominated subduction interface and is the site of repeated shallow (< 15 km depth) slow slip earthquakes (SSEs). The southern field area contrasts strongly, with deep (> 30 km) SSEs updip inferred to be associated with interseismic coupling on the plate interface, similar to Cascadia. Acquisition of ~15 high-resolution transects will increase the number of available heat flow measurements from this continental margin by 2 orders of magnitude. Using sediment seismic velocities and thermal conductivities obtained from this experiment, heatflow coverage will be expanded using regional observations of hydrate-related bottom simulating horizons. The project addresses fundamental questions about seismicity and deformation processes on a subduction plate interface, and how they may be linked to hydrologic and geodynamic processes. Students training will cover a range of techniques, from marine data collection and analysis to numerical modeling. Results of the study will be incorporated in university courses as well as included in community science outreach efforts.