International District Vent Field 1

The International District Vent Field 1 Medium-Power Junction Box (MJ03C) supports instruments to investigate the chemistry and temperatures of high temperature and diffuse flow vent sites within the International District Hydrothermal Field located along the eastern rift zone of Axial Seamount at a water depth of ~1,520 meters. Axial Seamount on the Juan de Fuca spreading center is an optimal site for a long-term observatory, as it is the most magmatically robust volcano on the spreading center and only one day by ship from the Washington and Oregon coasts. Additionally, the caldera hosts numerous active hydrothermal fields and abundant sites of diffuse flow. The main study sites include the actively venting chimneys called El Gordo, Escargot, and Diva. The El Gordo site also hosts a digital still camera and microbial DNA sampler. Coupled with the geophysical array on the summit of Axial Seamount, these instruments are designed to better understand linkages between seismicity, fluid temperatures and chemistry, and the evolution of biological communities over time in highly dynamic environment commonly perturbed by volcanic eruptions. A ~2.2 km-long electro-optical cable from Primary Node PN03B provides the junction box with significant power (375 V) and bandwidth (1 Gbs) to operate the instruments and transmit data to shore.