Stephen B DeLong, Ph.D.
I am a Supervisory Research Geologist in the USGS Earthquake Science Center. My primary focus is characterizing earthquake hazard in northern California. To do this I apply fieldwork, geochronology, terrestrial and airborne LiDAR, and a range of quantitative methods to zones of active crustal deformation. My broader expertise includes tectonic, hillslope and fluvial geomorphology, and I have applied these to interdisciplinary problems including earthquake hazard, landscape development, landsliding, ecological restoration, post-wildfire landscape change, coupled Earth systems experimentation, and the effects of flash floods and other active processes on the Earth's surface.
Ph.D. University of Arizona, Tucson AZ, 2006, Geosciences
B.S. University of Minnesota Duluth, Duluth MN, 1997 cum laude Major: Geology; Minor: Chemistry
U.S. Geological Survey, Earthquake Science Center, Supervisory Research Geologist, 2016 –
U.S. Geological Survey, Earthquake Science Center, Research Geologist, 2013 – 2016
University of Minnesota, Department of Earth Sciences, Graduate Faculty, 2016 - present
University of Arizona, Biosphere 2, Assistant Research Professor and Biosphere 2 Landscape Evolution Observatory lead scientist, March 2010 – February 2013
University of Arizona, Department of Geosciences, Assistant Research Professor (Joint), March 2010 – present
United States Geological Survey Mendenhall Postdoctoral Fellow, USGS Earthquake Science Center- Menlo Park, CA, October 2008 - August 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 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
Science and Products
Exploiting high-resolution topography for advancing the understanding of mass and energy transfer across landscapes: Opportunities, challenges, and needs
One of the grand challenges of Earth Surface Science and Natural Resource Management lies in the prediction of mass and energy transfer for large watersheds and landscapes. High resolution topography (lidar) datasets show potential to significantly advance our understanding of hydrologic and geomorphic processes controlling mass and energy transfer because they represent features at the...
Post-wildfire landscape change and erosional processes from repeat terrestrial lidar in a steep headwater catchment, Chiricahua Mountains, Arizona, USA
Flooding and erosion after wildfires present increasing hazard as climate warms, semi-arid lands become drier, population increases, and the urban interface encroaches farther into wildlands. We quantify post-wildfire erosion in a steep, initially unchannelized, 7.5 ha headwater catchment following the 2011 Horseshoe 2 Fire in the Chiricahua...DeLong, Stephen B.; Youberg, Ann M.; DeLong, Whitney M.; Murphy, Brendan P.
Spatio-temporal mapping of plate boundary faults in California using geodetic imaging
The Pacific–North American plate boundary in California is composed of a 400-km-wide network of faults and zones of distributed deformation. Earthquakes, even large ones, can occur along individual or combinations of faults within the larger plate boundary system. While research often focuses on the primary and secondary faults, holistic study of...Donnellan, Andrea; Arrowsmith, Ramon; DeLong, Stephen B.
Geomorphology, denudation rates, and stream channel profiles reveal patterns of mountain building adjacent to the San Andreas fault in northern California, USA
Relative horizontal motion along strike-slip faults can build mountains when motion is oblique to the trend of the strike-slip boundary. The resulting contraction and uplift pose off-fault seismic hazards, which are often difficult to detect because of the poor vertical resolution of satellite geodesy and difficulty of locating offset datable...DeLong, Stephen B.; Hilley, George E.; Prentice, Carol S.; Crosby, Christopher J.; Yokelson, Intan N.
CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape
Basalt weathering is a key control over the global carbon cycle, though in situ measurements of carbon cycling are lacking. In an experimental, vegetation-free hillslope containing 330 m3 of ground basalt scoria, we measured real-time inorganic carbon dynamics within the porous media and seepage flow. The hillslope carbon flux (0.6–...van Haren, Joost; Dontsova, Katerina; Barron-Gafford, Greg A.; Troch, Peter A.; Chorover, Jon; DeLong, Stephen B.; Breshears, David D.; Huxman, Travis E.; Pelletier, Jon D.; Saleska, Scott; Zeng, Xubin; Ruiz, Joaquin
Quantifying geomorphic change at ephemeral stream restoration sites using a coupled-model approach
Rock-detention structures are used as restoration treatments to engineer ephemeral stream channels of southeast Arizona, USA, to reduce streamflow velocity, limit erosion, retain sediment, and promote surface-water infiltration. Structures are intended to aggrade incised stream channels, yet little quantified evidence of efficacy is available. The...Norman, Laura M.; Sankey, Joel B.; Dean, David; Caster, Joshua J.; DeLong, Stephen B.; Henderson-DeLong, Whitney; Pelletier, Jon D.
Imaging of earthquake faults using small UAVs as a pathfinder for air and space observations
Large earthquakes cause billions of dollars in damage and extensive loss of life and property. Geodetic and topographic imaging provide measurements of transient and long-term crustal deformation needed to monitor fault zones and understand earthquakes. Earthquake-induced strain and rupture characteristics are expressed in topographic features...Donnellan, Andrea; Green, Joseph; Ansar, Adnan; Aletky, Joseph; Glasscoe, Margaret; Ben-Zion, Yehuda; Arrowsmith, J. Ramón; DeLong, Stephen B.
3D point cloud data from laser scanning along the 2014 South Napa Earthquake surface rupture, California, USA
Point cloud data collected along a 500 meter portion of the 2014 South Napa Earthquake surface rupture near Cuttings Wharf Road, Napa, CA, USA. The data include 7 point cloud files (.laz). The files are named with the location and date of collection and either ALSM for airborne laser scanner data or TLS for terrestrial laser scanner data. The ALSM...DeLong, Stephen B.
Tearing the terroir: Details and implications of surface rupture and deformation from the 24 August 2014 M6.0 South Napa earthquake, California
The Mw 6.0 South Napa earthquake of 24 August 2014 caused slip on several active fault strands within the West Napa Fault Zone (WNFZ). Field mapping identified 12.5 km of surface rupture. These field observations, near-field geodesy and space geodesy, together provide evidence for more than ~30 km of surface deformation with a relatively complex...DeLong, Stephen B.; Donnellan, Andrea; Ponti, Daniel J.; Rubin, Ron S.; Lienkaemper, James J.; Prentice, Carol S.; Dawson, Timothy E.; Seitz, Gordon G.; Schwartz, David P.; Hudnut, Kenneth W.; Rosa, Carla M.; Pickering, Alexandra J; Parker, Jay W.
Detailed mapping and rupture implications of the 1 km releasing bend in the Rodgers Creek Fault at Santa Rosa, northern California
Airborne light detection and ranging (lidar) topography reveals for the first time the trace of the Rodgers Creek fault (RCF) through the center of Santa Rosa, the largest city in the northern San Francisco Bay area. Vertical deformation of the Santa Rosa Creek floodplain expresses a composite pull‐apart basin beneath the urban cover that is part...Hecker, Suzanne; Langenheim, Victoria; Williams, Robert; Hitchcock, Christopher S.; DeLong, Stephen B.
Afterslip behavior following the M6.0, 2014 South Napa earthquake with implications for afterslip forecasting on other seismogenic faults
The M6.0, 24 Aug. 2014 South Napa, California, earthquake exhibited unusually large slip for a California strike-slip event of its size with a maximum coseismic surface slip of 40-50 cm in the north section of the 15 km-long rupture. Although only minor (<10 cm) surface slip occurred coseismically in the southern 9-km section of the rupture,...Lienkaemper, James J.; DeLong, Stephen B.; Domrose, Carolyn J; Rosa, Carla M.
Rates and patterns of surface deformation from laser scanning following the South Napa earthquake, California
The A.D. 2014 M6.0 South Napa earthquake, despite its moderate magnitude, caused significant damage to the Napa Valley in northern California (USA). Surface rupture occurred along several mapped and unmapped faults. Field observations following the earthquake indicated that the magnitude of postseismic surface slip was likely to approach or exceed...DeLong, Stephen B.; Lienkaemper, James J.; Pickering, Alexandra J; Avdievitch, Nikita N.
Trench logs, terrestrial lidar system imagery, and radiocarbon data from the kilometer-62 site on the Greenville Fault, southeastern Alameda County, California, 2014
In 2014, we investigated an abrupt 8.5-meter (m), right-laterally deflected stream channel located near the Greenville Fault in southeastern Alameda County, California (-121.56224° E, 37.53430° N) that we discovered using 0.5-m resolution, 2011 aerial lidar imagery flown along the active fault trace. Prior to trenching we surveyed the site...Lienkaemper, James J.; DeLong, Stephen B.; Avdievitch, Nikita N.; Pickering, Alexandra J; Guilderson, Thomas P.