A New Software for Visualization, Processing, and Analysis of Marine Heat Flow Measurements
Abstract
Marine heat flow measurements are critical to understanding Earth's thermal budget and the formation and evolution of the ocean floor. Modern, high-resolution studies require larger numbers of precise heat flow measurements. Calculation of heat fluxes at the seafloor requires knowledge of both the temperature and thermal conductivity variations with depth in the sediments beneath. Heat flow observations are typically obtained by inserting a thin cylindrical string outfitted with an array of thermistors into the sediments. Records of the decay that follows the initial frictional heating during penetration can then be fit to an ideal, theoretical model and extrapolated for temperatures of the undisturbed sediments. A second decay, resulting from a calibrated heating pulse of the sensor string, allows calculation of the in-situ conductivity of the sediments. Often, to save limited instrument power or ship time, it is necessary to forego the heat pulse and the second decay. We present new software for processing and analyzing seafloor heat flow data and evaluating measurement uncertainties. Our software allows processing of temperature records whether a heat pulse decay is available or not. In the latter case, the heat flux computations rely on user-specified conductivities. These can be supplied as a general conductivity-depth function. For this case, we iteratively determine the conductivity-depth sets consistent with both the user-supplied function and the temperatures extrapolated from the penetration decay. Uncertainties are estimated using a stochastic (Monte Carlo) analysis. This analysis combines temperature observations with uncertainties in the thickness of individual lithologic layers and, if desired, individual conductivity values. This analysis yields range and standard deviation of calculated heat flow values. In addition, our software allows for interactive graphical windowing of the raw temperature records and selection of sensors to process. Once sediment temperatures and conductivities are calculated, interactive discarding of bad temperature and/or conductivity points can be applied and heat fluxes recomputed. Our software also allows for automated batch processing of large numbers of heat flow measurements. Examples are shown from several settings, including both high-quality and "noisy" data.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFMOS11B0369C
- Keywords:
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- 3015 Heat flow (benthic) and hydrothermal processes;
- 3022 Marine sediments: processes and transport;
- 3094 Instruments and techniques;
- 5134 Thermal properties;
- 5194 Instruments and techniques