HR: 1340h
AN: V53B-1328    [Abstracts]
TI: Continuous real-time monitoring of chloride in geothermal areas in Yellowstone National Park: initial results from newly developed long-term in-situ chloride analyzers.
AU: * Chapin, T
EM: tchapin@usgs.gov
AF: U.S. Geological Survey, Box 25046, MS 964D Denver Federal Center, Denver, CO 80225, United States
AU: Heasler, H
EM: Henry_Heasler@nps.gov
AF: Yellowstone National Park, Yellowstone Center for Resources P.O. Box 168, Bldg. 27 Mammoth, WY, USA 82190, Mammoth, WY 82190, United States
AU: Hurwitz, S
EM: shaulh@usgs.gov
AF: U.S. Geological Survey, Bldg 15, McKelvey Building 345 Middlefield Road, MS 43, Menlo Park, CA 94025, United States
AB: Chloride in the surface waters of Yellowstone National Park is primarily derived from magmatic/hydrothermal sources. Discrete chloride measurements, collected at weekly to monthly intervals, are a key component of the ongoing geothermal monitoring program conducted by Yellowstone Volcano Observatory and National Park Service scientists. Chloride flux, estimated from discrete chloride measurements and streamflow data, could potentially be used as a proxy for geothermal heat flux and volcanic-geothermal unrest in the Park. However, infrequent chloride sampling restricts our understanding of dynamic geothermal processes, and the lack of real- time chloride data limits our ability to provide early warning and timely response to geologic hazards in Yellowstone. We seek to combine real-time chloride and streamflow data to examine variations in chloride flux due to changes in the volcanic-geothermal system and to determine if real-time chloride flux data can be used as an early warning indicator of volcanic hazards in the park. To address these objectives, we have developed a low-cost instrument for long-term, real-time, in-situ chemical analysis, the Field Sequential Injection Analyzer (Field-SIA). The Field-SIA is self-calibrating, performs hourly analyses for over two months between service visits, and integrates with existing USGS streamflow gaging stations which provide solar power and satellite telemetry of real-time chloride data. The Field-SIA greatly increases chemical data collection while significantly decreasing the cost of sampling and analysis. We will present data from long-term, high-resolution, real-time chloride monitoring of: 1) Tantalus Creek which drains the Norris Geyser Basin; 2) the Firehole River which drains the Upper, Middle, and Lower Geyser Basins; and 3) the Yellowstone River near Gardiner, MT. Initial results suggest that chloride fluctuations at Tantalus Creek were linked to diel temperature cycling while chloride fluctuations at the Firehole and Yellowstone River sites were more closely related to river flow.
DE: 1871 Surface water quality
DE: 1895 Instruments and techniques: monitoring
DE: 8424 Hydrothermal systems (0450, 1034, 3017, 3616, 4832, 8135)
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting