The Delta Dynamics Lab (DDL), maintained and operated by Ocean Networks Canada, has headed for a well-earned retirement after 21 successful deployments in the Fraser River Delta. The submarine observatory contributed to federal public safety programs related to natural hazards by providing a clearer understanding of the impact of the massive turbidity currents occurring in this region.
The final hoisting of the two-tonne custom-built structure during the [Spring 2024 #ONCabyss expedition](https://www.oceannetworks.ca/news-and-stories/stories/oncabyss-spring-2024-expedition-recap/) caps a 16-year joint geohazard investigation between ONC and Natural Resources Canada (NRCan) at the mouth of British Columbia’s longest river. Here, a nine-kilometre-wide intertidal mudflat off the coast of Metro Vancouver meets a sloping delta front that extends into the Strait of Georgia.
The initiative led by Drs. Gwyn Lintern and Philip Hill, NRCan research scientists and principal investigators for the DDL project, delivered unprecedented near year-round data capturing many of the unique delta processes such as sediment plume dynamics, underwater landslides, and the transfer of land-based sediment to the deep Salish Sea through turbidity currents.
The scale of the sediment transfer is significant. NRCan worked closely with UK researchers who have calculated that a single offshore turbidity current can move more sediment into the deep ocean than all the planet’s rivers combined. The Fraser River itself deposits over seven million tons of sediment annually during the spring freshet between May and June.