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Ocean Networks Canada is proud to offer the following pre-packaged datasets.
Collection: Ocean Networks Canada datasets related to deep-water renewal processes in the Strait of Georgia from 2008-2021
This collection contains datasets produced by Ocean Networks Canada between 2008-09 to 2021-12 from the Strait of Georgia (SOG) at the Central Node, and from the West Coast of Vancouver Island at the Folger Node, used in the publication “A Predictably Intermittent Rotationally Modified Gravity Current in the Strait of Georgia” by Masoud, M., Pawlowicz, R., and Dewey, R., (2022). The SOG Central Node, located in the south-central part of the Strait of Georgia (300 m), is located near the deepest part of the Strait’s cross-section and was designed in part to measure deep-water renewal processes which replace the bottom water of the Strait. These processes involve the downslope flow of dense water from the Boundary Pass area to the SE to the deepest parts of the Strait off Nanaimo to the NW. These downslope flows occur at monthly or biweekly intervals, and are often associated with a rise in turbidity near the bottom. There are also strong tidal currents. The Folger Node is at the mouth of Barkley Sound, and measurements of the density of bottom water can be used to deduce the timing of coastal upwelling processes on the West Coast.
These datasets include (1) water column currents at the Central Node, (2) the combined “State of the Ocean” datasets for the SOG Central Node and Folger Node which contain temperature, salinity, and density measurements, (3) turbidity measurements at the SOG Central Node, (4) water column currents and density measurements at an autonomous mooring placed near the SOG Central Node in 2018. Turbidity and water column current measurements in particular were subject to extensive post-processing and error correction. For full details on the quality control and processing of this data please see Masoud et al., (2022).
Six years (2009-2015) of oceanographic temperature, salinity, pressure, density and dissolved oxygen observations from a Vancouver Island shelf cabled observatory
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CTD profile in IODP CORK U1364A borehole at ONC NEPTUNE observatory site Clayoquot Slope, Cascadia Accretionary Prism
Ocean Networks Canada (ONC) operates and maintains innovative cabled observatories that supply continuous power and Internet connectivity to various scientific instruments located in coastal, deep-ocean, and Arctic environments. The Clayoquot Slope IODP (Integrated Ocean Discovery Program) borehole observatory CORK U1364A is located in the Vancouver Margin of the northern Cascadia Subduction Zone, ~20km landward of the accretionary prism toe. Here, sediments scraped from the subducting Juan de Fuca plate are deposited and the accreted sedimentary section is ~5 km thick with gas hydrate formation in the upper hundred meters of sediment. The CORK (Circulation Obviation Retrofit Kit) observatory was installed in 2010 during IODP Expedition 328 (Davis & Malone, 2010; Davis & Heesemann, 2011). This location was chosen to observe the fluid flow, mechanical and formation properties of the accretionary prism, allowing for long-term monitoring of deformation, seismic activity, and gas hydrate accumulation. In May 2014 a temperature profile was measured by lowering a CTD (Conductivity-Temperature-Depth) down IODP borehole observatory CORK U1364A. The CTD profile was obtained during Ocean Networks Canada NEPTUNE Maintenance Cruise 2014-05 using the remotely operated vehicle (ROV) CSSF-ROPOS from the CCGS John P. Tully. Dive log entries are available from Dive R1694 and a video recording of the experiment is accessible through SeaTube, ONC’s video player (https://data.oceannetworks.ca/SeaTube?resourceTypeId=1000&resourceId=1001&diveId=410&time=2014-05-24T15:43:08.000Z). CTD data was collected using the factory calibration settings and downloaded from the instrument using the CTD manufacturers software. The initial purpose of this experiment was to determine the open depth of the borehole. The data of the hydrological observatory have been used in multiple subsequent studies to investigate pressure and temperature changes of the subseafloor (Becker et al. 2020, Mcguire et al. 2018). Boreholes drilled within the accretionary prism help to better understand the relationship between dynamic processes such as tectonic motion and deformation, internal plate strain, and earthquakes, as well as gas hydrate formation and accumulation.
Prepared by Research Community
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