FY2004 Advanced Geophysical Methods Development

In FY2004, the USGS Office of Ground Water, Branch of Geophysics (OGW BG) continued development of advanced geophysical data processing methods. FY2004 work focused on development of methods for cross-hole radar tomography data analysis and borehole flowmeter data analysis. This research is supported by the USGS Toxic Substances Hydrology Program.

Processing Cross-Hole Radar Tomography Data

OGW BG is developing advanced methods for the processing of borehole-radar tomography data. The goal of this work is to improve the forward and inverse modeling tools available to the USGS for cross-hole radar tomography data processing and analysis. Current work builds on research conducted during FY2001-FY2003.

Figure 1. Field study slowness-difference tomography inversion results from a well pair: (a) Simultaneous iterative reconstruction technique (SIRT) method (Mean-Square Error (MSE) = 4.43 x 10-8 microseconds squared), (b) Weighted damped least-squares (WDLS) method (MSE = 1.01 x 10-7 microseconds squared).

In FY2004, application of new tomographic inversion methods was demonstrated on cross-hole radar field-data collected several years ago at the USGS Toxic Substance Hydrology Program Mirror Lake, New Hampshire, research site in order to image saline tracer transport in fractured rock using difference-attenuation radar tomography. Results of this work were published in FY2004 (see recent publications, below).

Work in FY2004 also investigated the limitations and pitfalls of using geophysical tomograms for geostatistical mapping of aquifer properties. A modeling approach was developed to assess the impacts of survey geometry, inversion method, and measurement errors on the utility of tomograms for geostatistics. The approach yields insights into the resolution of different survey and inversion scenarios (see recent publications, below). Work is continuing to extend the method to non-linear tomography and compare results for radar and electrical-resistivity tomography.

To facilitate research linking tomography and geostatistics, a new USGS software package for tomographic forward modeling and inversion is under development. The preliminary software package currently includes tools for forward modeling, inverse modeling, and resolution assessment. Prior to publication and distribution, additional work is anticipated in order to improve the user interface, incorporate additional inversion methods, and test and verify the algorithms.

This research was funded by the USGS Toxic Substances Hydrology Program.

This research was conducted by Fred Day-Lewis (USGS OGW BG) and John W. Lane, Jr. (USGS OGW BG) with assistance from OGW BG staff.

Processing Borehole Geophysical Flowmeter Data

A graphical user interface (GUI) to facilitate analysis of borehole flowmeter data has been developed and tested by OGW BG. The GUI facilitates data analysis using an existing flowmeter data analysis program developed by Fred Paillet (University of Maine, Department of Earth Sciences). The GUI requires further testing and review prior publication.

This research was funded by the USGS Toxic Substances Hydrology Program.

This research was conducted by Fred Day-Lewis (USGS OGW BG) and Carole D. Johnson (USGS OGW BG), with assistance from Fred Paillet and OGW BG staff.

Recent Publications:

Day-Lewis, F.D., and Lane, J.W., Jr., 2004, Assessing the resolution-dependent utility of tomograms for geostatistics: Geophysical Research Letters, v. 31, L07503, doi:10.1029/2004GL019617, 4 p.

Day-Lewis, F.D. and Lane, J.W., Jr, 2003, Use of crosshole radar tomograms for geostatistical estimation and simulation of interwell permeability - Limitations due to tomographic resolution [abs.]: Eos Transactions, American Geophysical Union, v. 84, no. 46, Fall Meeting Suppl., Abstract H21F-02.

Day-Lewis, F.D., Singha, Kamini, and Binley, A.M., 2004, On the pitfalls and limitations of applying petrophysical models to tomograms - Examples in cross-borehole radar and electrical resistivity tomography: EOS Trans., AGU, v. 85, no. 17, Jt. Assem. Suppl., Abstract NS13A-03.

Day-Lewis, F. D., Lane, J.W., Jr., Harris, J.M., and Gorelick, S.M., 2003, Time-lapse imaging of saline tracer tests using cross-borehole radar tomography: Water Resources Research, v. 39, no. 10, 14 p., 1290, doi:10.1029/2002WR001722.

Lane, J.W., Jr, 2003, Time-lapse geophysics for aquifer characterization and remediation monitoring [abs.]: Eos Transactions, American Geophysical Union, v. 84, no. 46, Fall Meeting Suppl., Abstract H21F-01.

Lane, J.W., Jr., Casey, C.C., Day-Lewis, F.D., Witten, A., and Versteeg, R.J., 2004, Use of borehole radar methods and borehole geophysical logs to monitor a field-scale vegetable oil biostimulation pilot project at Fridley, Minnesota, in Proceedings of the Fourth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 24-27, 2004, Monterrey California. Proceedings: Battelle Memorial Institute, CD-ROM, 9 p.

Lane, J.W., Jr., Day-Lewis, F.D., Versteeg, R.J., and Casey, C.C., 2004, Object-based inversion of crosswell radar tomography data to monitor vegetable oil injection experiments: Journal of Environmental & Engineering Geophysics, v. 9, no. 2, p. 63-77.

Lane, J.W., Jr., Day-Lewis, F.D., Versteeg, R.J., Casey, C.C., and Joesten, P.K., 2004, Application of cross-borehole radar to monitor field-scale vegetable oil injection experiments for biostimulation, in Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), 22 to 26 February, 2004, Colorado Springs, Proceedings: Denver, Colorado, Environmental and Engineering Geophysical Society, CD-ROM, 20 p.

Lane, J.W., Jr., Day-Lewis, FD, Versteeg, R.J., And Casey, C.C., 2003, Object-based inversion of crosswell radar tomography data to monitor vegetable-oil injection experiment, in Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), April 6-10, 2003, San Antonio, Texas, Proceedings: Denver, Colorado, Environmental and Engineering Geophysics Society, CD-ROM, 27 p.

For related information, see:

• FY2003 Advanced Geophysical Methods Development: Processing Cross-Hole Borehole-Radar Tomography Data
• FY2001 Theoretical Study of the Effects of Survey Geometry on Radar Tomography Resolution