3D Thermistor Array V18

During ROPOS Dive R1730, the NSF-OOI-RSN high-definition video camera was tested successfully. The camera was installed in 2013 and 1-year later it worked extremely well. A test 3-D thermistor array (bottom right) that was installed last year rests on a diffuse flow site, covered in microbial filaments. To the left, a cabled 3-D thermistor array will replace the uncabled system. Photo credit: NSF-OOI/UW/CSSF; Dive R1730; V14.

A custom thermistor array, developed by UW RSN Project Scientist Giora Proskurowski, includes four stacked triangular arrays with 24 individual temperature measurement points, providing a three-dimensional temperature distribution of fluids issuing from the summit of Axial Seamount. Temperatures are collected every 5 seconds from a diffuse flow site near the base of the active black smoker chimney called "Mushroom" in the ASHES hydrothermal field. Fluid temperatures may be impacted by lunar tides, earthquakes and changes in the subseafloor plumbing. These nutrient-rich fluids support novel microbial communities that thrive in the subsurface. The 3D array is couled with an osmotic fluid sampler that allows examination of changes in both temperature and fluid composition over time. All temperature data are streamed to the OOI Data Portal, where they can be viewed and downloaded. The osmotic samplers are recovered every year and the fluid compositions are analyzed onshore.