Research Faculty

Stephen DeLong

Assistant Research Professor, Biosphere 2
Assistant Research Professor, Department of Geosciences

Research Interests

Steve DeLong is a geologist that studies Earth surface processes. His interests include how climate and tectonics shape topography over timescales from individual storms to thousands of years.  He studies rates, patterns, and timing of sediment erosion and deposition; how flash floods shape landscapes, and how earthquakes shape landscape. He employs tools including environmental sensor networks, GPS, terrestrial and airborne laser scanning, geochronology, stratigraphy, surficial geologic mapping and a range of computational tools.

DeLong currently serves as lead scientist of the Biosphere 2 Landscape Evolution Observatory, a set of large-scale physical models built in an evironmentally controlled facility that are used to investigate a wide range of interdisciplinary Earth systems science topics.

DeLong's research group manages a Leica C10 ScanStation terrestrial laser scanner (LiDAR), a Leica Viva RTK GPS, and has expertise in a wide range of environmental sensor network technology. He is actively recruiting graduate students through the Department of Geosciences and is available for consultation and collaboration, especially in the areas of terrestrial LiDAR and use of environmental sensor networks in fluvial and tectonic geomorphology.

Education

• Ph.D. University of Arizona, Tucson AZ, 2006, Geosciences
• B.S. University of Minnesota Duluth, Duluth MN, 1997 cum laude Major: Geology; Minor: Chemistry

Employment

• University of Arizona, Biosphere 2, Assistant Research Professor and B2 Landscape Evolution Observatory lead scientist, March 2010 - present
• United States Geological Survey Mendenhall Postdoctoral Fellow, USGS Earthquake Science Center- Menlo Park, CA, October 2008 - October 2010
• Postdoctoral Research Associate, Arizona State University, Tempe, AZ, Aug 2007-October 2008
• Visiting Assistant Professor, Cornell College, Mount Vernon, IA, August 2006- May 2007
• Research Assistant, Los Alamos National Laboratory, 2005-2006
  Member of Yucca Mountain Project Igneous Hazards Team
• Teaching/Research Assistant, University of Arizona, Tucson, AZ, 2002-2005
• Geologist, United States Geological Survey, Tucson, AZ, summer 2002
• Geologist, Arizona Geological Survey, Tucson, AZ, 2002-2005

Publications

• DeLong, S. B., Johnson, J. P., Whipple, K.X., in prep, Channel head erosion in a flash-flood dominated discontinuous stream system
• DeLong, S. B.; Prentice, C. S., Hilley, G. E., Ebert, Y.  in press, ESPL, Multitemporal ALSM change detection, sediment delivery, and process mapping at an active earthflow
• DeLong, S.B., Pelletier, J.D., Arnold, L.J. in press, GSA Bulletin, Late Holocene alluvial history of the Cuyama River, California, USA
• DeLong, S. B., G. E. Hilley, M. J. Rymer, and C. Prentice, 2010, Fault zone structure from topography: Signatures of en echelon fault slip at Mustang Ridge on the San Andreas Fault, Monterey County, California, Tectonics, 29, TC5003, doi:10.1029/2010TC002673
• Hilley, G.E., DeLong, S.B., Prentice, C., Blisniuk, K., Arrowsmith, J.R., 2010, Morphologic dating of fault scarps using airborne laser swath mapping (ALSM) data. Geophys. Res. Lett., 37, L04301
• Arnold, L.J., Roberts, R.G., Galbraith, R.F., DeLong, S.B. 2009, A revised equivalent dose estimation procedure for optical dating of young and modern age sediments.  Quaternary Geochronology
• Pelletier, J.D., DeLong, S.B., Cline, M.L., Harrington, C.D., Keating, G.N., 2007, Dispersion of channel-sediment contaminants in distributary fluvial systems: Application to fluvial tephra and radionuclide redistribution following a potential volcanic eruption at Yucca Mountain.  Geomorphology
• DeLong, S.B., Pelletier, J.D., Arnold, L.J., 2008, Climate change triggered sedimentation and progressive tectonic uplift in a coupled piedmont-axial system: Cuyama Valley, California, U.S.A. Earth Surface Processes and Landforms
• DeLong, S.B., Minor, S.A., Arnold, L.J., 2007, Late Quaternary alluviation and offset along the eastern Big Pine fault, southern California. Geomorphology v. 90, p1-10
• DeLong, S.B., Pelletier, J.D. and Arnold, L., 2007, Bedrock landscape development modeling: Calibration using field study, geochronology and DEM analysis. Geological Society of America Bulletin v. 119, p. 157-173
• DeLong, S.B., Arnold, L., 2007, Dating alluvial deposits with optically-stimulated luminescence, AMS 14C and cosmogenic techniques, western Transverse Ranges, California. Quaternary Geochronlogy
• Pelletier, J.D., Cline, M.L., DeLong, S.B., 2007, Desert pavement dynamics: numerical modeling and field-based calibration. Earth Surface Process and Landforms
• Pelletier J. D., C. D. Harrington, J. W. Whitney, M. Cline, S. B. DeLong, G. Keating, K. T. Ebert, 2005, Geomorphic control of radionuclide diffusion in desert soils, Geophys. Res. Lett., 32, L23401, doi:10.1029/2005GL024347
• Pelletier, J.D., DeLong, S.B., Al-Suwaidi, A.H., Cline, M., Lewis, Y., Psillas, J.L., Yanites, B., 2006. Evolution of the Bonneville shoreline scarp in west-central Utah: Comparison of scarp-analysis methods and implications for the diffusion model of hillslope evolution. Geomorphology v. 74 p. 257-270
• Pelletier, J.D., and DeLong, S.B. 2004, Oscillations in arid alluvial-channel geometry, Geology 32: 713-71

Current Projects

• Lead Scientist, Biosphere 2 Landscape Evolution Observatory
  Project management for $7M project funded by Philecology Foundation
• Monitoring and evaluation of arroyo restoration measures, San Bernardino Ranch, Sonora, MX.  $18k from Biophilia Foundation, via Cuenca Los Ojos Foundation.
• Event scale landscape change in a flash flood-dominated discontinuous ephemeral stream using environmental sensors, tripod LiDAR, remote repeat photography, and repeat RTK-GPS surveys
• Fault zone evolution along the San Andreas Fault at Mustang Ridge, Monterey County
• Landscape development in Northern California using high resolution topographic data, field mapping, geochronology:
  - Sanborn Park, Santa Clara County
  - Ft Ross to Fort Bragg, North Coast
• Topographic change detection from airborne and tripod LiDAR in active geomorphic settings including earthflows, badlands, arroyos, bedrock channels

Past Projects

• Improving public understanding of the impact of climate change on the terrestrial water cycle and Arizona's water resources: $40k, UA Water Sustainability Program, completed July 2011.
• Fortified Peak, Cienega Creek, S. Arizona: Surficial geologic mapping, soils description, arroyo study
• Greater Cuyama Valley region, S. Coast Ranges California: Surficial geologic mapping, cosmogenic surface exposure dating sampling, radiocarbon sampling, luminescence dating sampling, EDM surveys, fault-slip history analysis, detailed stratigraphy.
• FortymileWash alluvial fan, Mojave Desert, CA/NV, USA: Surficial geologic mapping, desert surface development analyses, soils description
• Sunset Volcanic Field, N. Arizona: Analysis of geomorphic fate of airfall tephra, morphologic analyses of slopes and cinder cones
• Tule Valley, Utah: Slope-profile surveys, descriptive surficial analyses
• Utah, Arizona: Terrestrial LiDAR data acquisition in badlands, amphitheater valleys, bedrock channels
• Iowa and Minnesota:Use of surficial, bedrock, and glacial geology for teaching mapping, stratigraphy, sedimentology, hydrology and geomorphology.

Personnel

• Michael Sibayan, Engineer
• Whitney Henderson, Research Specialist
• Dave Millar, Research Technician
• Marielle Smith, GRA for Outreach and Exhibits, PhD student, EEB
• Ruben Ruiz, Videographer
• Paul Ingram, Journalism Intern (Graduate student in UA Journalism)
• Collaborator: Shipherd Reed (UA:Science Flandrau, Digital Media Producer)

Past:

• Intan N Yokelson, undergrad technician, summer 2011 (Now a Research Specialist in Geosciences Dept.)
• Brendan Murphy, Research Technician (now at UT-Austin Geology PhD program)
• Megan Ferre, Carleton College NSF-REU student, summer 2011