Earth's surface is shaped by the transfer of sediment across time and space. As we live on the Earth's surface, understanding this transport of sediment is key to the well-being of our species. I work on solving problems asscociated with landscapes and sediment transport using the tools of computer landscape evolution modeling and the trapped-charge phenomena known as luminescence.
Ph.D Geomorphology, University of Colorado - Boulder, 2018
M.S. Geology, Univeristy of Cincinnati, 2013
B.S. Earth Sciences, University of California - Santa Cruz, 2010
Science and Products
Filter Total Items: 17
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
Portable optically stimulated luminescence age map of a paleoseismic exposure
The quality and quantity of geochronologic data used to constrain the history of major earthquakes in a region exerts a first-order control on the accuracy of seismic hazard assessments that affect millions of people. However, evaluations of geochronological data are limited by uncertainties related to inherently complex depositional processes that may vary spatially and temporally. To improve con
A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis
A new history of great earthquakes (and their tsunamis) for the central and southern Cascadia subduction zone shows more frequent (17 in the past 6700 yr) megathrust ruptures than previous coastal chronologies. The history is based on along-strike correlations of Bayesian age models derived from evaluation of 554 radiocarbon ages that date earthquake evidence at 14 coastal sites. We reconstruct a
Landscape evolution in eastern Chuckwalla Valley, Riverside County, California
This study investigates sedimentary and geomorphic processes in eastern Chuckwalla Valley, Riverside County, California, a region of arid, basin-and-range terrain where extensive solar-energy development is planned. The objectives of this study were to (1) measure local weather parameters and use them to model aeolian sediment-transport potential; (2) identify surface sedimentary characteristics i
Depth-dependent soil mixing persists across climate zones
Soil mixing over long (>102 y) timescales enhances nutrient fluxes that support soil ecology, contributes to dispersion of sediment and contaminated material, and modulates fluxes of carbon through Earth’s largest terrestrial carbon reservoir. Despite its foundational importance, we lack robust understanding of the rates and patterns of soil mixing, largely due to a lack of long-timescale data. He
Luminescence as a sediment tracer and provenance tool
Luminescence holds unique potential as a sediment tracer and provenance method. The tracer application of luminescence has key advantages including ease of measurement, relatively low cost, and applicability to geologically ubiquitous quartz and feldspar sand and silt. These advantages can help answer fundamental questions about geomorphology, sediment transport, sediment production, and the tecto
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
Examining the relationship between portable luminescence reader measurements and depositional ages of paleowetland sediments, Las Vegas Valley, Nevada
Portable luminescence readers are exciting new tools that have the potential to rapidly determine the age structure of late Quaternary stratigraphic columns. This is important because high-resolution age profiling can reveal details about the temporal dynamics of climate cause and ecosystem effect, often while researchers are still in the field. In this paper, we compare new portable luminescence
Application of a luminescence‐based sediment transport model
Quantifying the transport history of sand is a challenging but important goal in geomorphology. In this paper, we take a simple idea that luminescence is bleached during transport and regenerates during storage, and use this as a basis to re‐envision luminescence as a sediment tracer. We apply a mathematical model describing luminescence through an idealized channel and reservoir system and then c
Dating of river terraces along Lefthand Creek, western High Plains, Colorado, reveals punctuated incision
The response of erosional landscapes to Quaternary climate oscillations is recorded in fluvial terraces whose quantitative interpretation requires numerical ages. We investigate gravel-capped strath terraces along the western edge of Colorado's High Plains to constrain the incision history of this shale-dominated landscape. We use ¹⁰Be and ²⁶Al cosmogenic radionuclides (CRNs), optically stimulated
On extracting sediment transport information from measurements of luminescence in river sediment
Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long-time scale (102–106 years) transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here we attempt to estimate sediment transport rates by using luminescence,
User guide for luminescence sampling in archaeological and geological contexts
Luminescence dating provides a direct age estimate of the time of last exposure of quartz or feldspar minerals to light or heat and has been successfully applied to deposits, rock surfaces, and fired materials in a number of archaeological and geological settings. Sampling strategies are diverse and can be customized depending on local circumstances, although all sediment samples need to include a
Earthquake Geology and Paleoseismology Overview
The goals of USGS earthquake geology and paleoseismology research are 1) to make primary observations and develop ideas to improve our understanding of the geologic expression of active faulting, and 2) to acquire data that will improve the National Seismic Hazard Model. Geological research allows us to characterize faults, including the identification of secondary seismogenic structures, to study...
Quaternary Hydroclimate Records of Spring Ecosystems
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited...
Western Basin & Range - Eastern California Shear Zone
The Eastern California Shear Zone (ECSZ) Mapping project, funded by the National Cooperative Geologic Mapping Program, combines surficial and bedrock geologic mapping, geophysical surveys, and high-resolution topographic data analysis with neotectonic, geomorphic, structural, volcanic, and geochronologic studies to better understand the tectonic framework and landscape evolution of the ECSZ in the...
Data Release for Luminescence: Mid to Late Quaternary Geomorphic and Paleoseismic Event History, Cheraw Fault, Colorado
Despite its subdued expression and isolated location within the Great Plains of southeastern Colorado, the 80-km-long Cheraw fault may be one of the most active faults in North America east of the Southern Rocky Mountains. We present geomorphic analyses, geochronology, and paleoseismic trenching data to 1) document the rupture history of the ~45-km-long southwestern section of the Cheraw fault ove
Data Release for Luminescence: Floodplain Sediment Storage Timescales of the Laterally Confined Meandering Powder River, U.S.A
The following report summarizes the dating results from the. Within this report, we detail the methodology used to determine the storage time distribution for a 17 km length of Powder River in Montana, U.S.A. by the age distribution of eroded sediment. This data is used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement,
Data release for luminescence: Edwards Air Force Base (CA) and CA Water Science Center report including luminescence data and ages
The following report summarizes the dating results from Aeolian deposits within and around Edwards Air Force Base in California. Within this report, we detail the methodology used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and dating related calculations. We recommend that this repo
DATA RELEASE Part 2: Optical luminescence dating of Bradley Lake, Oregon, tsunami deposits, analytical data for: A maximum rupture model for the central and southern Cascadia subduction zone-reassessing ages for coastal evidence of megathrust earthquakes
The following report summarizes the dating results from Bradley Lake, Oregon. Within this report, we detail the methodology used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and datingrelated calculations. We recommend that this report be included as the supplementary material for any
Luminescence, weather, and grain-size data from eastern Chuckwalla Valley, Riverside County, California
This data release contains luminescence, weather, and sediment grain-size data from eastern Chuckwalla Valley, Riverside County, California. This study investigates sedimentary and geomorphic processes in eastern Chuckwalla Valley, Riverside County, California, a region of arid, basin-and-range terrain where extensive solar-energy development is planned. The objectives were to (1) measure local we
Science and Products
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Filter Total Items: 17
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; ePortable optically stimulated luminescence age map of a paleoseismic exposure
The quality and quantity of geochronologic data used to constrain the history of major earthquakes in a region exerts a first-order control on the accuracy of seismic hazard assessments that affect millions of people. However, evaluations of geochronological data are limited by uncertainties related to inherently complex depositional processes that may vary spatially and temporally. To improve conA maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis
A new history of great earthquakes (and their tsunamis) for the central and southern Cascadia subduction zone shows more frequent (17 in the past 6700 yr) megathrust ruptures than previous coastal chronologies. The history is based on along-strike correlations of Bayesian age models derived from evaluation of 554 radiocarbon ages that date earthquake evidence at 14 coastal sites. We reconstruct aLandscape evolution in eastern Chuckwalla Valley, Riverside County, California
This study investigates sedimentary and geomorphic processes in eastern Chuckwalla Valley, Riverside County, California, a region of arid, basin-and-range terrain where extensive solar-energy development is planned. The objectives of this study were to (1) measure local weather parameters and use them to model aeolian sediment-transport potential; (2) identify surface sedimentary characteristics iDepth-dependent soil mixing persists across climate zones
Soil mixing over long (>102 y) timescales enhances nutrient fluxes that support soil ecology, contributes to dispersion of sediment and contaminated material, and modulates fluxes of carbon through Earth’s largest terrestrial carbon reservoir. Despite its foundational importance, we lack robust understanding of the rates and patterns of soil mixing, largely due to a lack of long-timescale data. HeLuminescence as a sediment tracer and provenance tool
Luminescence holds unique potential as a sediment tracer and provenance method. The tracer application of luminescence has key advantages including ease of measurement, relatively low cost, and applicability to geologically ubiquitous quartz and feldspar sand and silt. These advantages can help answer fundamental questions about geomorphology, sediment transport, sediment production, and the tectoPaleoseismic 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 vertExamining the relationship between portable luminescence reader measurements and depositional ages of paleowetland sediments, Las Vegas Valley, Nevada
Portable luminescence readers are exciting new tools that have the potential to rapidly determine the age structure of late Quaternary stratigraphic columns. This is important because high-resolution age profiling can reveal details about the temporal dynamics of climate cause and ecosystem effect, often while researchers are still in the field. In this paper, we compare new portable luminescenceApplication of a luminescence‐based sediment transport model
Quantifying the transport history of sand is a challenging but important goal in geomorphology. In this paper, we take a simple idea that luminescence is bleached during transport and regenerates during storage, and use this as a basis to re‐envision luminescence as a sediment tracer. We apply a mathematical model describing luminescence through an idealized channel and reservoir system and then cDating of river terraces along Lefthand Creek, western High Plains, Colorado, reveals punctuated incision
The response of erosional landscapes to Quaternary climate oscillations is recorded in fluvial terraces whose quantitative interpretation requires numerical ages. We investigate gravel-capped strath terraces along the western edge of Colorado's High Plains to constrain the incision history of this shale-dominated landscape. We use ¹⁰Be and ²⁶Al cosmogenic radionuclides (CRNs), optically stimulatedOn extracting sediment transport information from measurements of luminescence in river sediment
Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long-time scale (102–106 years) transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here we attempt to estimate sediment transport rates by using luminescence,User guide for luminescence sampling in archaeological and geological contexts
Luminescence dating provides a direct age estimate of the time of last exposure of quartz or feldspar minerals to light or heat and has been successfully applied to deposits, rock surfaces, and fired materials in a number of archaeological and geological settings. Sampling strategies are diverse and can be customized depending on local circumstances, although all sediment samples need to include a - Science
Earthquake Geology and Paleoseismology Overview
The goals of USGS earthquake geology and paleoseismology research are 1) to make primary observations and develop ideas to improve our understanding of the geologic expression of active faulting, and 2) to acquire data that will improve the National Seismic Hazard Model. Geological research allows us to characterize faults, including the identification of secondary seismogenic structures, to study...Quaternary Hydroclimate Records of Spring Ecosystems
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited...Western Basin & Range - Eastern California Shear Zone
The Eastern California Shear Zone (ECSZ) Mapping project, funded by the National Cooperative Geologic Mapping Program, combines surficial and bedrock geologic mapping, geophysical surveys, and high-resolution topographic data analysis with neotectonic, geomorphic, structural, volcanic, and geochronologic studies to better understand the tectonic framework and landscape evolution of the ECSZ in the... - Data
Data Release for Luminescence: Mid to Late Quaternary Geomorphic and Paleoseismic Event History, Cheraw Fault, Colorado
Despite its subdued expression and isolated location within the Great Plains of southeastern Colorado, the 80-km-long Cheraw fault may be one of the most active faults in North America east of the Southern Rocky Mountains. We present geomorphic analyses, geochronology, and paleoseismic trenching data to 1) document the rupture history of the ~45-km-long southwestern section of the Cheraw fault oveData Release for Luminescence: Floodplain Sediment Storage Timescales of the Laterally Confined Meandering Powder River, U.S.A
The following report summarizes the dating results from the. Within this report, we detail the methodology used to determine the storage time distribution for a 17 km length of Powder River in Montana, U.S.A. by the age distribution of eroded sediment. This data is used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement,Data release for luminescence: Edwards Air Force Base (CA) and CA Water Science Center report including luminescence data and ages
The following report summarizes the dating results from Aeolian deposits within and around Edwards Air Force Base in California. Within this report, we detail the methodology used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and dating related calculations. We recommend that this repoDATA RELEASE Part 2: Optical luminescence dating of Bradley Lake, Oregon, tsunami deposits, analytical data for: A maximum rupture model for the central and southern Cascadia subduction zone-reassessing ages for coastal evidence of megathrust earthquakes
The following report summarizes the dating results from Bradley Lake, Oregon. Within this report, we detail the methodology used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and datingrelated calculations. We recommend that this report be included as the supplementary material for anyLuminescence, weather, and grain-size data from eastern Chuckwalla Valley, Riverside County, California
This data release contains luminescence, weather, and sediment grain-size data from eastern Chuckwalla Valley, Riverside County, California. This study investigates sedimentary and geomorphic processes in eastern Chuckwalla Valley, Riverside County, California, a region of arid, basin-and-range terrain where extensive solar-energy development is planned. The objectives were to (1) measure local we