NEPTUNE Canada Seismograph Network
Robert Meldrum (Geological Survey of Canada), John Cassidy (Geological Survey of Canada, University of Victoria), Michael Bostock (University of British Columbia), Andrew Calvert (Simon Fraser University), William Wilcock (University of Washington), Paul McGill (Monterey Bay Aquarium Research Institute)
The NEPTUNE Canada Seismograph Network will consist initially of four broadband/strong motion seismographs and four short period seismographs. Three broadband/strong motion seismographs were installed in September 2009 near the nodes at ODP 1027, ODP 889 and Barkley Canyon. In the summer of 2010, a broadband/strong motion instrument and the short period instruments will be installed on Juan de Fuca ridge. As well, ancillary instruments and back up batteries will be installed at sites instrumented in 2009.
There will be four broadband seismograph observatories one will be deployed on the Endeavour segment of the Juan de Fuca ridge, one will be mid plate at ODP 1027 and two will be on the continental slope near ODP 889 and Barkley Canyon. Broadband instrument/strong motion packages are buried just below the seafloor.
The four short period instruments will be installed on the Ridge near the broadband system, together forming a small array, 6 km in maximum dimension, to record earthquake activity in the vicinity of the many multidisciplinary ridge experiments. Short period instruments will be installed in coreholes drilled in volcanic rock or in concrete monuments deployed on sediment.
The broadband systems will comprise three component broadband seismometers and strong motion accelerometers in a surficially buried spherical titanium case, with a current meter, hydrophone and differential pressure gauge nearby. The short period systems will include 3-component corehole seismometers on long term loan from the Monterey Bay Aquarium Research Institute (MBARI). All systems will have backup capacity for modest cable outages.
The intent of the NEPTUNE Canada Seismograph Network is to provide the scientific community with an observation and research tool to allow the same kind of research that takes place on land to take place within the NEPTUNE Canada footprint on the ocean floor. This includes studying Earth structure and studying earthquakes on the Juan de Fuca Ridge to due to tectonic, magmatic and hydrothermal processes, earthquakes along the offshore fracture zones, earthquakes within the oceanic plate as it begins to subduct, and mid-plate earthquakes. Of particular interest is the relationship of earthquakes to the multidisciplinary experiments on the Endeavour segment of the Juan de Fuca Ridge. Data flow from the NEPTUNE Canada Seismograph Network will be integrated in real time with the adjacent land based Canadian National Seismograph Network operated by the Geological Survey of Canada. It is planned that seismic data will be available to researchers through IRIS in early 2010.