For over three decades, a fundemental goal for scientific ocean drilling has been to understand the role of the presence and flow of water in marine geologic formations on processes like heat loss from the earth, chemical exchange between the Earth’s oceans and crust, support of subseafloor microbiological ecosystems, and the creation of methane-hydrates and ore deposits. The quality of direct observations is commonly compromised by a simple problem: boreholes create hydrologic “short circuits” that allow open exchange of water between subseafloor formations and the ocean. The resulting perturbations severely limit the utility of temperature and pressure observations and of water samples taken during or shortly after drilling operations.
Scientists from Canada and France began deploying a cabled piezometer at 9:45 am (PDT) on Wednesday, July 6, 2011 at the Cascadia Basin site. This is the first operation of the NEPTUNE Canada July 2011 installation and maintenance expedition on the R/V Thompson. In visible company was the R/V Atlantis, the sister ship of the R/V Thompson, with a crew of researchers working on nearby Ocean Drilling Program (ODP) boreholes, an illustration of the high interest in the thin oceanic crust of the Juan de Fuca tectonic plate.
When a devastating magnitude 8.0 earthquake occurred roughly 200 km south of the Samoan Islands at 17:48:11 UTC on Tuesday September 29, 2009, it generated a trans-oceanic tsunami that spread at jet-like speeds throughout the Pacific Ocean.
At 04:57:33 UTC on 30 September, roughly 11 hours after the earthquake, five of our newly deployed Bottom Pressure Recorders (BPRs) and one...