As an earthquake geologist, I use numerical modeling, field observations, and quantitative analysis of remotely sensed data to investigate earthquake history of active faults and how earthquake history is recorded in a landscape. This work informs seismic hazard models and future risk.
I co-led the USGS-Hazards Unlearning Racism in Geoscience (URGE) pod and am invovled with ongoing JEDI/DEIA efforts at the GHSC and USGS. Please email me to chat more about unlearning racism in geoscience, the URGE program, and ongoing efforts.
Professional Experience
Research Geologist, USGS, 2020-Present
Geologist, USGS, 2014-2016
Physical Science Technician, Denali National Park, 2010, 2011, 2013
Education and Certifications
PhD, University of Colorado Boulder, 2016-2020
MS, University of Colorado Boulder, 2011-2013
BA, Vassar College, 2006-2010
Science and Products
How Big and How Frequent Are Earthquakes on the Wasatch Fault?
Release Date: FEBRUARY 1, 2015 Paleoseismology along the Wasatch Fault in Utah is helping to estimate the shaking risk to nearby towns.
Strike-slip in transtension: Complex crustal architecture of the Warm Springs Valley fault zone, northern Walker Lane
This data release contains field data for two P-wave seismic reflection profiles acquired across the Warm Springs Valley fault zone, part of the Northern Walker Lane, NV. The dataset consists of high-resolution seismic reflection field records in .segy format, shot coordinates in .csv format, and observers? logs in .pdf format. The high-resolution seismic profiles are approximately 4 km long. The
Compilation of offset measurements and fault data for global strike-slip faults with multiple earthquakes
This Data Release provides the compilation of offset measurement datasets and associated fault data to accompany the manuscript "Climatic influence on the expression of strike-slip faulting" by Reitman et al. In addition to a ReadMe file, it includes two tabular datasets, one code, and one text file. The datasets are a compilation of offset measurement data ("data_multiple_eq_offset
Plotting multiple fault representations: Applications for National Seismic Hazard Model 2023 update (NSHM-faultmaps)
The National Seismic Hazard Model (NSHM) utilizes a fault sections database (FSD) throughout the model workflow. Working towards a 2023 NSHM release, the NSHM23 FSD encompasses a major update with the addition of new fault sections, as well as the revision of existing fault sections from prior FSD (2014). The additions and revisions were largely based on the U.S. Geological Survey's Quaternary Fau
Filter Total Items: 15
Climatic influence on the expression of strike-slip faulting
Earthquakes on strike-slip faults are preserved in the geomorphic record by offset landforms that span a range of displacements, from small offsets created in the most recent earthquake (MRE) to large offsets that record cumulative slip from multiple prior events. An exponential decay in the number of large cumulative offsets has been observed on many faults, and a leading hypothesis is that clima
How similar was the 1983 Mw 6.9 Borah Peak earthquake rupture to its surface-faulting predecessors along the northern Lost River fault zone (Idaho, USA)?
We excavated trenches at two paleoseismic sites bounding a trans-basin bedrock ridge (the Willow Creek Hills) along the northern Lost River fault zone to explore the uniqueness of the 1983 Mw 6.9 Borah Peak earthquake compared to its prehistoric predecessors. At the Sheep Creek site on the southernmost Warm Springs section, two earthquakes occurred at 9.8−14.0 ka (95% confidence) and 6.5−7.1 ka; e
Geophysical constraints on the crustal architecture of the transtensional Warm Springs Valley fault zone, northern Walker Lane, western Nevada, USA
The Walker Lane is a zone of distributed transtension where normal faults are overprinted by strike-slip motion. We use two newly-acquired high-resolution seismic reflection profiles and a reprocessed Consortium for Continental Reflection Profiling (COCORP) deep crustal reflection profile to assess the subsurface geometry of the Holocene-active, transtensional Warm Springs Valley fault zone (WSVFZ
The influence of frost weathering on the debris flow sediment supply in an alpine basin
Rocky, alpine mountains are prone to mass wasting from debris flows. The Chalk Cliffs
study area (central Colorado, USA) produces debris flows annually. These debris flows
are triggered when overland flow driven by intense summer convective storms mobilizes
large volumes of sediment within the channel network. Understanding the debris flow
hazard in this, and similar alpine settings, requires
Offset channels may not accurately record strike-slip fault displacement: Evidence from landscape evolution models
Slip distribution, slip rate, and slip per event for strike‐slip faults are commonly determined by correlating offset stream channels—under the assumption that they record seismic slip—but offset channels are formed by the interplay of tectonic and geomorphic processes. To constrain offset channel development under known tectonic and geomorphic conditions, we use numerical landscape evolution simu
Holocene rupture history of the central Teton fault at Leigh Lake; Grand Teton National Park, Wyoming
Prominent scarps on Pinedale glacial surfaces along the eastern base of the Teton Range confirm latest Pleistocene to Holocene surface‐faulting earthquakes on the Teton fault, but the timing of these events is only broadly constrained by a single previous paleoseismic study. We excavated two trenches at the Leigh Lake site near the center of the Teton fault to address open questions about earthqua
Variable normal-fault rupture behavior, northern Lost River fault zone, Idaho, USA
The 1983 Mw 6.9 Borah Peak earthquake generated ∼36 km of surface rupture along the Thousand Springs and Warm Springs sections of the Lost River fault zone (LRFZ, Idaho, USA). Although the rupture is a well-studied example of multisegment surface faulting, ambiguity remains regarding the degree to which a bedrock ridge and branch fault at the Willow Creek Hills influenced rupture progress. To expl
Paleoseismic results from the Alpine site, Wasatch fault zone: Timing and displacement data for six holocene earthquakes at the Salt Lake City–Provo segment boundary
To improve the characterization of Holocene earthquakes on the Wasatch fault zone (WFZ), we conducted light detection and ranging (lidar)‐based neotectonic mapping and excavated a paleoseismic trench across an 8‐m‐high fault scarp near Alpine, Utah, located ∼6.2–0.4 ka∼6.2–0.4 ka. Interseismic recurrence ranges from 0.2 to 1.8 ky (mean 1.2 ky). We estimate 6.5±0.7 m6.5±0.7 m of cumulative vert
Combining conflicting Bayesian models to develop paleoseismic records—An example from the Wasatch Fault Zone, Utah
Bayesian statistical analyses of paleoseismic data result in the probabilistic determination of earthquake times using geochronological data evaluated in the context of a stratigraphic model. However, a fundamental problem in paleoseismology is how to use the Bayesian approach to model sparse and/or conflicting geochronological datasets, such as those derived from sites exhibiting episodic sedimen
P- and S-wave velocity models incorporating the Cascadia subduction zone for 3D earthquake ground motion simulations, Version 1.6—Update for Open-File Report 2007–1348
In support of earthquake hazard studies and ground motion simulations in the Pacific Northwest, three-dimensional P- and S-wave velocity (VP and VS, respectively) models incorporating the Cascadia subduction zone were previously developed for the region encompassed from about 40.2°N. to 50°N. latitude, and from about 122°W. to 129°W. longitude. This report describes updates to the Cascadia velocit
Recurrent Holocene movement on the Susitna Glacier Thrust Fault: The structure that initiated the Mw 7.9 Denali Fault earthquake, central Alaska
We conducted a trench investigation and analyzed pre‐ and postearthquake topography to determine the timing and size of prehistoric surface ruptures on the Susitna Glacier fault (SGF), the thrust fault that initiated the 2002 Mw 7.9 Denali fault earthquake sequence in central Alaska. In two of our three hand‐excavated trenches, we found clear evidence for a single pre‐2002 earthquake (penultimate
Holocene earthquakes of magnitude 7 during westward escape of the Olympic Mountains, Washington
The Lake Creek–Boundary Creek fault, previously mapped in Miocene bedrock as an oblique thrust on the north flank of the Olympic Mountains, poses a significant earthquake hazard. Mapping using 2015 light detection and ranging (lidar) confirms 2004 lidar mapping of postglacial (≥14 km along a splay fault, the Sadie Creek fault, west of Lake Crescent. Scarp morphology suggests repeated earthquake r
Non-USGS Publications**
Reitman, N.G. and P. Molnar (2021) Strain and velocity across the Great Basin derived from 15-ka fault slip rates: Implications for continuous deformation and seismic hazards in the Walker Lane, California-Nevada, USA. Tectonics. doi: 10.1029/2020TC006389
Reitman, N.G. and P. Molnar (2020) Input parameters, output data, and script to calculate strain and velocity from fault source parameters. [Data set]. Zenodo. https://doi.org/10.5281/zenodo.3895334
Reitman, N.G., K.J. Mueller, G.E. Tucker, R.D. Gold, R.W. Briggs, and K.R. Barnhart. (2019) Numerical model code and input files to run landscape evolution models with strike-slip faulting and measure channel offsets. [Data set]. Zenodo. http://doi.org/10.5281/zenodo.3374026
Litchfield, N.J., K.J. Clark, U.A. Cochran, J. Mountjoy, C. Mueller, R. Morgenstern, K.R. Berryman, B.G. McFadgen, R. Steele, N.G. Reitman, J. Howarth, and P. Villamor. (2020) Unraveling complex coastal deformation mechanisms using marine terrace paleoseismology Puatai Beach and Pakarae River mouth, northern Hikurangi Margin, New Zealand. Bulletin of the Seismological Society of America. doi: 10.1785/0120190208
Reitman, N.G., Ge, S., and Mueller, K. (2014) Groundwater flow and its effect on salt dissolution in Gypsum Canyon watershed, Paradox Basin, southeast Utah, USA. Hydrogeology Journal, doi: 10.1007/s10040-014-1126-0.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
How Big and How Frequent Are Earthquakes on the Wasatch Fault?
Release Date: FEBRUARY 1, 2015 Paleoseismology along the Wasatch Fault in Utah is helping to estimate the shaking risk to nearby towns. - Data
Strike-slip in transtension: Complex crustal architecture of the Warm Springs Valley fault zone, northern Walker Lane
This data release contains field data for two P-wave seismic reflection profiles acquired across the Warm Springs Valley fault zone, part of the Northern Walker Lane, NV. The dataset consists of high-resolution seismic reflection field records in .segy format, shot coordinates in .csv format, and observers? logs in .pdf format. The high-resolution seismic profiles are approximately 4 km long. TheCompilation of offset measurements and fault data for global strike-slip faults with multiple earthquakes
This Data Release provides the compilation of offset measurement datasets and associated fault data to accompany the manuscript "Climatic influence on the expression of strike-slip faulting" by Reitman et al. In addition to a ReadMe file, it includes two tabular datasets, one code, and one text file. The datasets are a compilation of offset measurement data ("data_multiple_eq_offsetPlotting multiple fault representations: Applications for National Seismic Hazard Model 2023 update (NSHM-faultmaps)
The National Seismic Hazard Model (NSHM) utilizes a fault sections database (FSD) throughout the model workflow. Working towards a 2023 NSHM release, the NSHM23 FSD encompasses a major update with the addition of new fault sections, as well as the revision of existing fault sections from prior FSD (2014). The additions and revisions were largely based on the U.S. Geological Survey's Quaternary Fau - Publications
Filter Total Items: 15
Climatic influence on the expression of strike-slip faulting
Earthquakes on strike-slip faults are preserved in the geomorphic record by offset landforms that span a range of displacements, from small offsets created in the most recent earthquake (MRE) to large offsets that record cumulative slip from multiple prior events. An exponential decay in the number of large cumulative offsets has been observed on many faults, and a leading hypothesis is that climaHow similar was the 1983 Mw 6.9 Borah Peak earthquake rupture to its surface-faulting predecessors along the northern Lost River fault zone (Idaho, USA)?
We excavated trenches at two paleoseismic sites bounding a trans-basin bedrock ridge (the Willow Creek Hills) along the northern Lost River fault zone to explore the uniqueness of the 1983 Mw 6.9 Borah Peak earthquake compared to its prehistoric predecessors. At the Sheep Creek site on the southernmost Warm Springs section, two earthquakes occurred at 9.8−14.0 ka (95% confidence) and 6.5−7.1 ka; eGeophysical constraints on the crustal architecture of the transtensional Warm Springs Valley fault zone, northern Walker Lane, western Nevada, USA
The Walker Lane is a zone of distributed transtension where normal faults are overprinted by strike-slip motion. We use two newly-acquired high-resolution seismic reflection profiles and a reprocessed Consortium for Continental Reflection Profiling (COCORP) deep crustal reflection profile to assess the subsurface geometry of the Holocene-active, transtensional Warm Springs Valley fault zone (WSVFZThe influence of frost weathering on the debris flow sediment supply in an alpine basin
Rocky, alpine mountains are prone to mass wasting from debris flows. The Chalk Cliffs study area (central Colorado, USA) produces debris flows annually. These debris flows are triggered when overland flow driven by intense summer convective storms mobilizes large volumes of sediment within the channel network. Understanding the debris flow hazard in this, and similar alpine settings, requiresOffset channels may not accurately record strike-slip fault displacement: Evidence from landscape evolution models
Slip distribution, slip rate, and slip per event for strike‐slip faults are commonly determined by correlating offset stream channels—under the assumption that they record seismic slip—but offset channels are formed by the interplay of tectonic and geomorphic processes. To constrain offset channel development under known tectonic and geomorphic conditions, we use numerical landscape evolution simuHolocene rupture history of the central Teton fault at Leigh Lake; Grand Teton National Park, Wyoming
Prominent scarps on Pinedale glacial surfaces along the eastern base of the Teton Range confirm latest Pleistocene to Holocene surface‐faulting earthquakes on the Teton fault, but the timing of these events is only broadly constrained by a single previous paleoseismic study. We excavated two trenches at the Leigh Lake site near the center of the Teton fault to address open questions about earthquaVariable normal-fault rupture behavior, northern Lost River fault zone, Idaho, USA
The 1983 Mw 6.9 Borah Peak earthquake generated ∼36 km of surface rupture along the Thousand Springs and Warm Springs sections of the Lost River fault zone (LRFZ, Idaho, USA). Although the rupture is a well-studied example of multisegment surface faulting, ambiguity remains regarding the degree to which a bedrock ridge and branch fault at the Willow Creek Hills influenced rupture progress. To explPaleoseismic results from the Alpine site, Wasatch fault zone: Timing and displacement data for six holocene earthquakes at the Salt Lake City–Provo segment boundary
To improve the characterization of Holocene earthquakes on the Wasatch fault zone (WFZ), we conducted light detection and ranging (lidar)‐based neotectonic mapping and excavated a paleoseismic trench across an 8‐m‐high fault scarp near Alpine, Utah, located ∼6.2–0.4 ka∼6.2–0.4 ka. Interseismic recurrence ranges from 0.2 to 1.8 ky (mean 1.2 ky). We estimate 6.5±0.7 m6.5±0.7 m of cumulative vertCombining conflicting Bayesian models to develop paleoseismic records—An example from the Wasatch Fault Zone, Utah
Bayesian statistical analyses of paleoseismic data result in the probabilistic determination of earthquake times using geochronological data evaluated in the context of a stratigraphic model. However, a fundamental problem in paleoseismology is how to use the Bayesian approach to model sparse and/or conflicting geochronological datasets, such as those derived from sites exhibiting episodic sedimenP- and S-wave velocity models incorporating the Cascadia subduction zone for 3D earthquake ground motion simulations, Version 1.6—Update for Open-File Report 2007–1348
In support of earthquake hazard studies and ground motion simulations in the Pacific Northwest, three-dimensional P- and S-wave velocity (VP and VS, respectively) models incorporating the Cascadia subduction zone were previously developed for the region encompassed from about 40.2°N. to 50°N. latitude, and from about 122°W. to 129°W. longitude. This report describes updates to the Cascadia velocitRecurrent Holocene movement on the Susitna Glacier Thrust Fault: The structure that initiated the Mw 7.9 Denali Fault earthquake, central Alaska
We conducted a trench investigation and analyzed pre‐ and postearthquake topography to determine the timing and size of prehistoric surface ruptures on the Susitna Glacier fault (SGF), the thrust fault that initiated the 2002 Mw 7.9 Denali fault earthquake sequence in central Alaska. In two of our three hand‐excavated trenches, we found clear evidence for a single pre‐2002 earthquake (penultimateHolocene earthquakes of magnitude 7 during westward escape of the Olympic Mountains, Washington
The Lake Creek–Boundary Creek fault, previously mapped in Miocene bedrock as an oblique thrust on the north flank of the Olympic Mountains, poses a significant earthquake hazard. Mapping using 2015 light detection and ranging (lidar) confirms 2004 lidar mapping of postglacial (≥14 km along a splay fault, the Sadie Creek fault, west of Lake Crescent. Scarp morphology suggests repeated earthquake rNon-USGS Publications**
Reitman, N.G. and P. Molnar (2021) Strain and velocity across the Great Basin derived from 15-ka fault slip rates: Implications for continuous deformation and seismic hazards in the Walker Lane, California-Nevada, USA. Tectonics. doi: 10.1029/2020TC006389Reitman, N.G. and P. Molnar (2020) Input parameters, output data, and script to calculate strain and velocity from fault source parameters. [Data set]. Zenodo. https://doi.org/10.5281/zenodo.3895334Reitman, N.G., K.J. Mueller, G.E. Tucker, R.D. Gold, R.W. Briggs, and K.R. Barnhart. (2019) Numerical model code and input files to run landscape evolution models with strike-slip faulting and measure channel offsets. [Data set]. Zenodo. http://doi.org/10.5281/zenodo.3374026Litchfield, N.J., K.J. Clark, U.A. Cochran, J. Mountjoy, C. Mueller, R. Morgenstern, K.R. Berryman, B.G. McFadgen, R. Steele, N.G. Reitman, J. Howarth, and P. Villamor. (2020) Unraveling complex coastal deformation mechanisms using marine terrace paleoseismology Puatai Beach and Pakarae River mouth, northern Hikurangi Margin, New Zealand. Bulletin of the Seismological Society of America. doi: 10.1785/0120190208Reitman, N.G., Ge, S., and Mueller, K. (2014) Groundwater flow and its effect on salt dissolution in Gypsum Canyon watershed, Paradox Basin, southeast Utah, USA. Hydrogeology Journal, doi: 10.1007/s10040-014-1126-0.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.