Northern Cascadia Subduction Zone Observatory (NCSZO): an interdisciplinary research initiative to assess tsunami and earthquake hazard from the Cascadia megathrust

There is presently insufficient information to accurately assess the hazard posed by a tsunamigenic megathrust earthquake rupturing the Cascadia Subduction Zone in the Pacific Northwest. We report our plans to deploy a Northern Cascadia Subduction Zone Observatory (NCSZO) offshore Vancouver Island, Canada, which will comprise a seafloor network of seven new Global Positioning System sites to measure deformation caused by the subduction of the oceanic Juan de Fuca Plate beneath the continental North America Plate, and a Deformation Front Laboratory at the oceanic trench to monitor aseismic creep events on the shallow part of the plate interface. The NCSZO will make effective and sustainable use of the Ocean Networks Canada NEPTUNE observatory, and be complemented by the highest density of land-based seismic and high-rate geodetic stations in Canada. We expect the NCSZO will enable significant improvements of tsunami and earthquake risks assessments after only a few years of measurements.