Temporal and comparative variability of Fe, CO2, and O2 of Loihi Seamount hydrothermal systems
Hydrothermal systems are visible representations of geological processes at work. Since their discovery, studies have shown them to be remarkable natural features with unique properties, such as venting fluids at extreme temperatures and supporters of unusual biological communities (Juniper 2003). I would like to examine the effect of recent eruptions and seismicity on the hydrothermal systems of Loihi, a seamount 34 km south of the largest island of Hawaii, to determine whether the chemical makeup of the plume has changed since the last published measurements in 2006 were taken. Discovered in Determining the differences of the Loihi vent fields over time regarding Fe, O2, and CO2 abundance, could give possible insight to infer certain geological and biological processes going on, creating, sustaining, and continuously transforming these venting systems. A comparison of the venting fluids could enable a prediction of biological activity, from the chemical composition of the plume. I would like to sample the plume itself and determine the chemical constituents, paying attention to iron, oxygen, and carbon dioxide. The work will be done during the cruise on the R/V Thomas G. Thompson to take place between December 27th, and January 4th. There will be no constraints as to time of day, however ample time will be needed to make the CTD casts and tow yos, hopefully at several locations. Samples evaluated in the past have been taken using a variety of equipment including CTD samples and physical samples from submersibles (Damm et al, 2006). Samples will be obtained using a CTD with a Niskin Rosette sampling in and near the neutrally-buoyant plume, as well as open ocean as a control. In the case of extreme weather, sampling stations will be established from which we will cast the CTD vertically at predetermined stations. This study hopes to better the understanding of the relationship between seismicity and hydrothermal activity and the variability in chemical composition of plumes of intraplate systems over time.