Cabling a Tectonic Plate—Continuous Live Data from the Cascadia Subduction Zone is Enabled through Ocean Networks Canada's NEPTUNE Observatory and the Ocean Observatories Initiative's Cabled Array

Abstract:

Ocean Networks Canada (ONC) and the Ocean Observatories Initiative (OOI) have established cabled observatories that span the entire Juan de Fuca plate, from the North-American west coast, across the Cascadia subduction zone, to the Juan de Fuca Ridge. These cabled observatories provide power and high bandwidth internet connectivity to the seafloor, enabling continuous and high resolution real-time data acquisition. This combination serves several important purposes for seismology, geodesy and tectonics: seismograph data from the top of the subduction zone are available in real time to significantly improve the localization in particular of small to intermediate subduction zone earthquakes, typically the precursors of large megathrust events, whose detection was traditionally limited by the sensitivity of land seismographs. In addition, bottom pressure recorders are detecting tsunamis in real-time which helps live updating of tsunami models before far field tsunamis fall on land. Finally, long-term seafloor geodesy experiments can be installed without the need to recover or replace them with fresh batteries but instead bury them deeply such as in boreholes. Most cabled installations on both the Canadian and US observatories are completed and have been streaming live data to shore, readily available to monitoring agencies and researchers (seismometer data is available from IRIS, the Incorporated Research Institute for Seismology).