Establishing a new era of submarine volcanic observatories: Cabling Axial Seamount and the Endeavour Segment of the Juan de Fuca Ridge

At least 70% of the volcanism on Earth occurs along the 65,000 km network of mid-ocean ridge (MOR) spreading centers. Within these dynamic environments, the highest fluxes of heat, chemicals, and biological material from the lithosphere to the hydrosphere occur during volcanic eruptions. However, because underwater volcanoes are difficult and expensive to access, researchers are rarely, if ever, in the right place at the right time to characterize these events. Therefore, our knowledge is limited about the linkages among hydrothermal, chemical and biological processes during seafloor formation and crustal evolution. To make significant advancements in understanding the evolution of MOR environments, the United States and Canada have invested in the first plate-scale submarine cabled observatory linked through the global Internet. Spanning the Juan de Fuca tectonic plate, these two networks include > 1700 km of cable and 14 subsea terminals that provide 8–10 kW power and 10 Gbs communications to hundreds of instruments on the seafloor and throughout the overlying water column — resulting in a 24/7/365 presence in the oceans. Data and imagery are available in real- to near-real time.
The initial experimental sites for monitoring volcanic processes include the MOR volcanoes called Axial Seamount and the Endeavour Segment that are located on the Juan de Fuca Ridge. Axial, a hot-spot influenced seamount, is the most robust volcano along the ridge rising nearly 1400 m above the surrounding seafloor and it has erupted twice in the last 15 years. In contrast, the Endeavour Segment is characterized by more subdued topography with a well defined axial rift and it hosts one of the most intensely venting hydrothermal systems known. A non-eruptive spreading event lasting 6 years was documented at Endeavour between 1999 and 2005. Hydrothermal venting intensity, chemistry, and temperature, as well as associated biological communities at both sites were significantly perturbed by the magmatic and intrusive events. This paper presents the similarities and differences between the Axial and Endeavour volcanic systems and identifies reasons why they are ideal candidates for comparative studies. The U.S. has made a 25-year commitment for sustained observations using the cabled infrastructure. The highly expandable nature of submarine optical networking will allow for the future addition of novel experiments that utilize ever evolving advancements in computer sciences, robotics, genomics and sensor miniaturization. Comprehensive modeling of the myriad processes involved will continue to assimilate and integrate growing databases yielding a new understanding of integrated processes that create the seafloor in the global ocean basins.

Regional Cabled