American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 742716 bytes)    Cited by

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. B11, 2297, doi:10.1029/2001JB001654, 2002

Episodic thermal perturbations associated with groundwater flow: An example from Kilauea Volcano, Hawaii

Shaul Hurwitz

U.S. Geological Survey, Menlo Park, California, USA


Steven E. Ingebritsen

U.S. Geological Survey, Menlo Park, California, USA


Michael L. Sorey

U.S. Geological Survey, Menlo Park, California, USA


Abstract

Temperature measurements in deep drill holes on volcano summits or upper flanks allow a quantitative analysis of groundwater induced heat transport within the edifice. We present a new temperature-depth profile from a deep well on the summit of Kilauea Volcano, Hawaii, and analyze it in conjunction with a temperature profile measured 26 years earlier. We propose two groundwater flow models to interpret the complex temperature profiles. The first is a modified confined lateral flow model (CLFM) with a continuous flux of hydrothermal fluid. In the second, transient flow model (TFM), slow conductive cooling follows a brief, advective heating event. We carry out numerical simulations to examine the timescales associated with each of the models. Results for both models are sensitive to the initial conditions, and with realistic initial conditions it takes between 750 and 1000 simulation years for either model to match the measured temperature profiles. With somewhat hotter initial conditions, results are consistent with onset of a hydrothermal plume ∼550 years ago, coincident with initiation of caldera subsidence. We show that the TFM is consistent with other data from hydrothermal systems and laboratory experiments and perhaps is more appropriate for this highly dynamic environment. The TFM implies that volcano-hydrothermal systems may be dominated by episodic events and that thermal perturbations may persist for several thousand years after hydrothermal flow has ceased.

Published 15 November 2002.

Index Terms: 1878 Hydrology: Water/energy interactions; 3210 Mathematical Geophysics: Modeling; 8424 Volcanology: Hydrothermal systems (8135); 3230 Mathematical Geophysics: Numerical solutions; 1829 Hydrology: Groundwater hydrology.

Read Full Article (file size: 742716 bytes)    Cited by

Citation: Hurwitz, S., S. E. Ingebritsen, and M. L. Sorey (2002), Episodic thermal perturbations associated with groundwater flow: An example from Kilauea Volcano, Hawaii, J. Geophys. Res., 107(B11), 2297, doi:10.1029/2001JB001654.