Axial Base Seafloor

The Axial Base Seafloor site is located near the base of the Axial Seamount at the far western edge of the Juan de Fuca tectonic plate, at ~2,600 meters water deep. The site contains a Medium-Power junction box (MJ03A) and a Low-Power junction box (LJ03A). Axial Seamount is the largest and most magmatically robust volcano on the Juan de Fuca Ridge, ~350 km from the continental shelf, and represents an open-ocean or pelagic site in the continuum of observing scales represented in the Regional Cabled Array. Here, large-scale currents including the North Pacific Current, the subpolar gyre, and the northern end of the California Current interact. These currents transport heat, salt, oxygen, and biota, all of which are crucial to the region’s ecosystem. Their variability ranges across timescales from daily tides to seasonal winds to interannual El Niño events to Pacific Decadal Oscillations. These junction boxes contain geophysical and near-seafloor water column instrumentation, and are attached to an electro-optic cable that provides significant power and 1 Gb two-way communications bandwidth. This seafloor site is co-located with a Deep and Shallow Profiler Mooring, which collect complementary water column data.