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Near Surface Geophysics Research Group

The Near-Surface Geophysics Group uses geophysical field studies and theoretical numerical experiments to address a wide range of geological, hydrogeological, and volcanological questions. Our common focus as a group is the suite of geophysical methods we use: seismology, magnetics, gravity, near-surface seismics, electromagnetics, resistivity, SP, ground penetrating radar, and others. Our studies range in scale from a few meters (for example high-resolution imaging of sinkholes) to regional investigations of volcano seismicity and structure.


From left: Christine Downs, Sanaz Esmaeili, Sarah Kruse, Henok Kiflu, Sajad Jazayeri

Research Projects

  • Resistivity imaging with buried electrode arrays: Post-doc Henok Kiflu with David Harro, M.H. Loke, and Paul Wilkinson. Resistivity imaging suffers from lack of resolution at depth and at the ends of resistivity arrays at sites where access restricts the length of a resistivity profile. This group has worked to develop and assess methods for improving resistivity imaging with a buried electrode array beneath 2D or 3D surface arrays. Henok one of your beautiful 3D res images here?

    Kiflu, H., S. Kruse, M.H. Loke, P. Wilkinson, and D. Harro, Improving resistivity survey resolution at sites with limited spatial extent through buried electrode arrays, accepted, Journal of Applied Geophysics. link

  • Sinkhole subsidence processes: Post-doc Henok Kiflu . We are working collaboratively with Shimon Wdowinski (FIU) and Talib Oliver-Cabrera (U Miami) to image sinkhole structures with GPR, resistivity, and seismics. We will also model sinkhole deformation at sites where InSAR data show evidence of subsidence, or where known subsidence is occurring. This work is funded by NSF.

    Image from S. Wdowinski

  • Sandhill wetland hydrogeology Ph.D. student Christine Downs. We are working with ReNae Nowicki and Mark Rains from the Ecohydrology Research Group to understand the hydrogeologic framework of sandhill wetlands. Our contribution is the acquisition, processing, and interpretation of GPR and seismic data from 5 wetland sites in west-central Florida. This work is funded by the Southwest Florida Water Management District. Report

    Christine and Sajad configuring the GPR before floating it over a wetland pool.

  • Understanding EM response in high conductivity (hypersaline) wetlands: PhD student Christine Downs with Chet Weiss (Sandia Labs). We are using Chet Weiss' APhiD code to assess the resolution capabilities of EM-31 and EM-34 data for detecting hydrogeologically significant layers in mangrove wetlands.

    Example numerical results from APhiD with a schematic of the EM-31.

  • Improved resolution of buried objects with ground penetrating radar using full-waveform inversion: PhD student Sajad Jazayeri with Anya Klotzsche and Jan van der Kruk. We combine PEST and gprMax to do full-waveform inversion of GPR profiles to extract information on target properties.

    Full-Waveform Inversion Method on GPR data to improve the applicability of geophysics in engineering applications.

  • Lava tube imaging: PhD student Sanaz Esmaeili. With Kelsey Young and Patrick Whelley. We will investigate a combination of terrestrial laser scanning, handheld XRF, and GPR in the development of a strategy for the exploration of lava tube and pit-rich environments. This work is funded by NASA.

    Lava tube

  • Ice Volume in Scarisoara Ice Cave: MS student Jackson Hubbard with Bogdan Onac. We are compiling a grid of GPR profiles with a total station to determine the volume of ice in Scarisoara Cave in Romania.

  • Mapping faults in Crater Lake National Park: With Charlie Bacon, Joel Robinson, Judy McIlrath, and Lis Gallant. We are processing and interpreting GPR profiles over faults that pre-date (but by how much?) the climactic 7.7 ka Crater Lake eruption.

    Hiking with equipment to the field area.

  • Developing a toolkit to boost introductory geophysics and geophysics instruction: PhD student Sanaz Esmaeili with Charly Bank, Ophelia George, Konstantinos Papadimitrios, Eva Zhang, Alexander Cadmus. We are developing a software toolkit which fills a critical void in educational materials necessary to achieve key geophysics learning outcomes. This work is funded by MathWorks.

Near-Surface Geophysics Publications

Jazayeri, S., A. Klotzsche, and S. Kruse, Determining pipe diameter and infilling material with full waveform inversion of common-offset GPR data using PEST, submitted to Geophysics.

Kiflu, H., S. Kruse, M.H. Loke, P. Wilkinson, and D. Harro, Improving resistivity survey resolution at sites with limited spatial extent through buried electrode arrays, accepted, Journal of Applied Geophysics.

Ammar, A.I., and S.E. Kruse, Resistivity Soundings and VLF Profiles for Siting Groundwater Wells in a Fractured Basement Aquifer in the Arabian Shield, Saudi Arabia, Journal of African Earth Sciences, 116, 56-67, 2016.

Loke, M.H., H. Kiflu, P.B. Wilkinson, D. Harro, and S. Kruse, Optimized arrays for 2-D resistivity surveys with combined surface and deep arrays, Near Surface Geophysics,13,505-517, 2015.

Marshall, A., C. Connor, S. Kruse, R. Malservisi, J. Richardson, L. Courtland, L. Connor, J. Wilson, and M.A. Karegar, Subsurface structure of a maar-diatreme and associated tuff ring from a high-resolution geophysical survey, Rattlesnake Crater, Arizona, Journal of Volcanology and Geothermal Research, 304, 253-264, 2015.

George, O.A., J. McIlrath, A. Farrell, E. Gallant, S. Tavarez, A. Marshall, C. McNiff, M. Njoroge, J. Wilson, C. Connor, L. Connor, and S. Kruse, High-Resolution Ground-Based Magnetic Survey of a Buried Volcano: Anomaly B, Amargosa Desert, NV, Statistics in Volcanology, 1, 1-23, 2015.

Bumpus, P., and S. Kruse, Self-potential monitoring for hydrological investigations in urban covered-karst terrain, Geophysics 79, B231-B242, 2014.

Ettinger, S., V. Manville, S. Kruse, and R. Paris, GPR-derived architecture of a lahar-generated fan at Cotopaxi volcano, Ecuador, Geomorphology, 213, 225-239, 2014.

Courtland, L., S. Kruse, and C. Connor, Violent Strombolian or not? Using ground-penetrating radar to distinguish deposits of low- and high-energy scoria cone eruptions, Bulletin of Volcanology, 75: 760, 13 p., 2013.

Montero, W., J. Lewis, J. Marshall, S. Kruse, and P. Wetmore, Neotectonic faulting and fore arc sliver motion along the Atirro-Rió Sucio fault system, Costa Rica, Central America, GSA Bulletin, 125, 857-876, 2013.

Mwashote, B. M., M. Murray, W.C. Burnett, J. Chanton, S. Kruse, and A. Forde, Submarine groundwater discharge in the Sarasota Bay system: Its assessment and implications for the nearshore coastal environment, Continental Shelf Research, 53, 63-76, 2013.

Kruse, S., Near-Surface Geophysics in Geomorphology. In: John F. Shroder (Editor-in-chief), Bishop, M.P. (Volume Editor). Treatise on Geomorphology, Vol 3, Remote Sensing and GIScience in Geomorphology, San Diego: Academic Press; 2013. p. 103-129.

van Gaalen, J. F., S. Kruse, W. B. Lafrenz and S. M. Burroughs, Predicting water table response to rainfall events, Central Florida, Ground Water, 51 (3), 350-362, doi: 10.1111/j.1745-6584.2012.00970.x, 2013.

Courtland, L.M., S.E. Kruse, C.B. Connor, L.J. Connor, and I.P. Savov, GPR investigation of tephra fallout, Cerro Negro Volcano, Nicaragua; a method for constraining parameters used in tephra sedimentation models, Bulletin of Volcanology, 74, 1409-1424, 2012.

van Gaalen, J., S. Kruse, G. Coco, L. Collins, and T. Doering, Observations of beach cusp evolution at Melbourne Beach, Florida, USA, Geomorphology, 129,131-140, 2011.

Kruse, S., R. Mora, C. Ramirez, and G. Alvarado, Ground penetrating radar imaging of tephra stratigraphy on Poás and Irazú volcanoes, Costa Rica, Revista Geológica de América Central, 43, 119-136, 2010.

Stringer, C.E., M.C. Rains, S. Kruse, and D. Whigham, Controls on water levels and salinity in a barrier island mangrove, Indian River Lagoon, Florida, Wetlands, 30, 725-734, DOI 10.1007/s13157-010-0072-4, 2010.

Hickey, T.D., Hine, A.C., Shinn, E.A., Cunningham, K.J., Kruse, S.E., and Poore, R.Z., Pleistocene carbonate stratigraphy of south Florida: evidence for high-frequency sea-level cyclicity, Journal of Coastal Research, 264,605-614, DOI: 10.2112/JCOASTRES-D-09-00052.1, 2010.

Diez, M., C. B. Connor, S.E. Kruse, L. Connor, and I.P. Savov, Evidence of small-volume igneous diapirism in the shallow crust of the Colorado Plateau, San Rafael desert, Utah, Lithosphere, 2009, 1, 328-336, doi:10.1130/L61, 2009.

Wetmore, P. H., C. B. Connor, S. E. Kruse, S. Callihan, G. Pignotta, C. Stremtan, and A. Burke, Geometry of the Trachyte Mesa intrusion, Henry Mountains, Utah: Implications for the emplacement of small melt volumes into the upper crust, Geochemistry, Geophysics, Geosystems 10, 8, doi:10.1029/2009GC002469, 2009.

van Gaalen, J.F., S.E. Kruse, S.M. Burroughs, and G. Coco, Time-frequency methods for characterizing cuspate landforms in Lidar data, Journal of Coastal Research, 25(3), 1143-1148, 2009.

Guha, S., S. Kruse, and P. Wang, Joint time-frequency analysis of GPR data over layered sequences, The Leading Edge, 27 (11), 1454-1460, 2008.

Swarzenski, P.W., F.W. Simonds, A.J. Paulson, S. Kruse, and C. Reich, Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA, Environ. Sci. & Technol, 41(20), 7022-7029, 2007.

Montero, W. and S. Kruse, Neotectónica y geofísica de la Falla Aguacaliente en los valles de Coris y de El Guarco, Revista Geológica de América Central, 34-35, 43-58, 2006.

Denyer, P., G. Cárdenes, and S. Kruse, Registro histórico y evolución de la barra arenosa de Puntarenas, Golfo de Nicoya, Costa Rica, Revista Geológica de América Central, 31, 45-59, 2006.

Kruse, S., M. Grasmueck, M. Weiss, and D. Viggiano, Sinkhole structure imaging in covered karst terrain, Geophysical Research Letters, 33, L16405, doi:10.1029/2006GL026975, 2006.

Guha, S., S.E. Kruse, E.E. Wright, and U.E. Kruse, Spectral analysis of ground penetrating radar response to thin sedimentary layers, Geophysical Research Letters, 32, L23304, doi:10.1029/2005GL023933, 2005.

Greenwood, W.J., S.E. Kruse, and P. Swarzenski, Extending electromagnetic methods to map coastal pore water salinities, Groundwater, doi: 10.1111/j.1745-6584.2005.00137.x, 2005.

Schneider, J.A. and S.E. Kruse, Assessing natural and anthropogenic impacts on freshwater lens morphology on small barrier islands: Dog Island and St. George Island, Florida, Hydrogeology Journal, 14, 131-145, doi 10.1007/s10040-005-0442-9, 2005.

Moore, L.J., H.M. Jol, S. Kruse, S. Vandenburgh, and G. Kaminsky, Annual layers revealed by GPR in the subsurface of a prograding coastal barrier, southwest Washington, U.S.A., J. Sedimentary Research, 74(5), 690-696, 2004.

Meadows, D.G., J. P. Caballero, S. E. Kruse, and H. L. Vacher., Variation of salinity in brackish-water lenses of two Florida Keys, Journal of Coastal Geology, 20(2), 386-400, 2004.

Peterson, V., S. Yurkovich, J. Burr, J. Ryan, and S. Kruse, A collaborative field-laboratory summer Research Experiences for Undergraduates (REU) program in geosciences, Council on Undergraduate Research Quarterly, 24, 1, 13-17, 2003.

Schneider, J.A. and S.E. Kruse, A comparison of controls on freshwater lens morphology of small carbonate and siliciclastic islands: Examples from barrier islands in Florida, USA, Journal of Hydrology, 284, 253-269, 2003.

Kruse, S.E. and H.M. Jol, Amplitude analysis of repetitive GPR reflections on a Lake Bonneville delta, Utah, in Ground Penetrating Radar in Sediments, Bristow, C.S. and Jol, H.M. (eds), Geological Society, London, Special Publications, 211, 287-298, 2003.

Kruse, S.E., S.F. Tebbens, D.F. Naar, Q. Lou, and R.T. Bird, Comparisons of gravity anomalies from pseudofaults, fracture zones, and nontransform discontinuities from fast to slow spreading areas, J. Geophys. Res., 105, 28,399-28,410, 2000.

Ruppel, C., G. Schultz, and S. Kruse, Anomalous fresh water lens morphology on a strip barrier island, Ground Water, 38, 872-881, 2000.

Kruse, S.E., J.C. Schneider, D.J. Campagna, J.A. Inman, and T.D. Hickey, Ground penetrating radar imaging of cap rock, caliche and carbonate strata, Journal of Applied Geophysics, 43, 239-249, 2000.

Kruse, S., M. Brudzinski, and T. Geib, Use of electrical and electromagnetic techniques to map seawater intrusion near the Cross-Florida Barge Canal, Environmental & Engineering Geoscience, 4, 331-340, 1998.

Johnson, G.H., S.E. Kruse, A.W. Vaughn, J.K. Lucey, C.H. Hobbs III, and D.S. Powars, Post-impact deformation associated with the late Eocene Chesapeake Bay impact structure in southeastern Virginia, Geology, 26, 507-510, 1998.

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Volcano Research Group
Seismology Research Group
Ecohydrology Research Group
Karst Research Group

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