Location: 46.1082ºN 129.6182ºW Water Depth: 2650-2654 meters
The Axial Base study site at Primary Node PN3A is located on the southeastern base of Axial Seamount and provides an ideal location for studies of open-ocean circulation and flow of currents over steep, rough topography. 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 North Pacific ecosystem. Forces such as wind and tidal currents, as well as annual and decadal phenomena such as El Niño and the Pacific Decadal Oscillation, generate variabilities in the ocean system. Much remains to be understood about such variabilities, which can have major effects not only on marine ecosystems, but also on land-based ecosystems, including weather patterns and food production on the continents.
In addition to these oceanographic processes, we hope to capture a megaplume event associated with an eruption of the volcano. Megaplumes are huge (20 km across), slightly warm plumes of fluid that issue from the subseafloor and from new lava flows. They may rise >3000 feet above the seafloor and they carry novel microbial communities that once thrived in the subsurface. They have never been characterized in real-time yet they are important because they inject significant amounts of heat, chemicals and biological material into the overlying ocean. In addition, fine-grained particles of metals in the plumes are used as colonization sites for microbes.
In 2014, instruments designed to investigate geophysical processes (e.g. earthquakes ) and two state-of-the-art instrumented moored profilers will be deployed at this site.
Infrastructure and instruments to be installed at the Axial Seamount Base (PN3A) site include the following:
- Extension Cables (in 2013)
- Medium-Power Junction Boxes
- Bottom Pressure Recorder/Pressure Sensor
- Broadband Seismometer
- Broadband Hydrophone
- Current Meter + Temperature