Publications
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Establishing chronologies for alluvial-fan sequences with analysis of high-resolution topographic data: San Luis Valley, Colorado, USA
On active alluvial fans, debris-flow deposits and frequent avulsions produce a rough topographic surface. As is the case in many initially rough landforms produced by catastrophic processes, the topography of alluvial fans is progressively smoothed, producing textural differences useful in establishing relative age criteria for fans. Here, we outline an approach for defining a quantitative, numeri
Authors
Samuel Johnstone, Adam M. Hudson, Sylvia Nicovich, Chester A. Ruleman, Robert M. Sare, Ren A. Thompson
Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: a multi-biomarker reconstruction from Paru Co
The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation of
Authors
Alice Callergaro, Dario Battistel, Natalie M. Kehrwald, Felipe Matsubara Pereira, Torben Kirchgeorg, Maria del Carmen Villoslada Hidalgo, Broxton W. Bird, Carlo Barbante
Iron dissolution and speciation in atmospheric mineral dust: Metal-metal synergistic and antagonistic effects
Under acidic atmospheric conditions, iron leached from atmospheric mineral dust may influence the distribution of bioavailable iron at a global scale. However, the effects of non-Fe-containing minerals on iron dissolution remain unknown. This work describes metal-metal synergistic and antagonistic effects on iron dissolution that go beyond aggregation and ionic strength effects in mineral dust mix
Authors
Eshani Hettiarachchi, Richard L. Reynolds, Harland L. Goldstein, Bruce M. Moskowitz, Gayan Rubasinghege
A decade of remotely sensed observations highlight complex processes linked to coastal permafrost bluff erosion in the Arctic
Eroding permafrost coasts are indicators and integrators of changes in the Arctic System as they are susceptible to the combined effects of declining sea ice extent, increases in open water duration, more frequent and impactful storms, sea-level rise, and warming permafrost. However, few observation sites in the Arctic have yet to link decadal-scale erosion rates with changing environmental condit
Authors
Benjamin M. Jones, Louise M. Farquharson, Carson Baughman, Richard M. Buzard, Christopher D. Arp, Guido Grosse, Diana L. Bull, Frank Günther, Ingmar Nitze, Frank Urban, Jeremy L. Kasper, Jennifer M. Frederick, Matthew A. Thomas, Craig Jones, Alejandro Mota, Scott Dallimore, Craig E. Tweedie, Christopher V. Maio, Daniel H. Mann, Bruce M. Richmond, Ann E. Gibbs, Ming Xiao, Torsten Sachs, Go Iwahana, Mikhail Z. Kanevskiy, Vladimir E. Romanovsky
Machine learning for ecosystem services
Recent developments in machine learning have expanded data-driven modelling (DDM) capabilities, allowing artificial intelligence to infer the behaviour of a system by computing and exploiting correlations between observed variables within it. Machine learning algorithms may enable the use of increasingly available ‘big data’ and assist applying ecosystem service models across scales, analysing and
Authors
Simon Willcock, Javier Martinez-Lopez, Danny A.P. Hooftman, Kenneth J. Bagstad, Stefano Balbi, Alessia Marzo, Carlo Prato, Saverio Sciandrello, Giovanni Signorello, Brian Voigt, Ferdinando Villa, James M. Bullock, Ioannis Athanasiadis
Towards globally customizable ecosystem service models
Scientists, stakeholders and decision makers face trade-offs between adopting simple or complex approaches when modeling ecosystem services (ES). Complex approaches may be time- and data-intensive, making them more challenging to implement and difficult to scale, but can produce more accurate and locally specific results. In contrast, simple approaches allow for faster assessments but may sacrific
Authors
Javier Martinez-Lopez, Kenneth J. Bagstad, Stefano Balbi, Ainhoa Magrach, Brian Voigt, Ioannis Athanasiadis, Marta Pascual, Simon Willcock, Ferdinando Villa
Overview of the oxygen isotope systematics of land snails from North America
Continental paleoclimate proxies with near-global coverage are rare. Land snail δ18O is one of the few proxies abundant in Quaternary sediments ranging from the tropics to the high Arctic tundra. However, its application in paleoclimatology remains difficult, attributable in part to limitations in published calibration studies. Here we present shell δ18O of modern small (<10 mm) snails across Nort
Authors
Yurena Yanes, Nasser M. Al-Qattan, Jason A. Rech, Jeffrey S. Pigati, Justin P. Dodd, Jeffrey C. Nekola
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
Authors
Harrison J. Gray, Shannon A. Mahan, Kathleen B. Springer, Jeffrey S. Pigati
Juke Box trench: A valuable archive of late Pleistocene and Holocene stratigraphy in the Bonneville basin, Utah
A backhoe trench in deposits of Pleistocene Lake Bonneville and Holocene wetlands below the mouth of Juke Box Cave, near Wendover, Utah, provides an excellent view of the late Pleistocene and Holocene geologic history of the area. The following stratigraphic units are exposed (ascending): preBonneville gravel (fluvial or lacustrine) and oolitic sand (ages greater than 30,000 yr B.P.); Lake Bonnevi
Authors
Charles G. Oviatt, Jeffrey S. Pigati, David B. Madsen, David E. Rhode, Jordon Bright
Time series of high-resolution images enhances efforts to monitor post-fire condition and recovery, Waldo Canyon fire, Colorado, USA
Interpretations of post-fire condition and rates of vegetation recovery can influence management priorities, actions and perception of latent risks from landslides and floods. In this study, we used the Waldo Canyon fire (2012, Colorado Springs, Colorado, USA) as a case study to explore how a time series (2011–2016) of high-resolution images can be used to delineate burn extent and severity, as we
Authors
Melanie K. Vanderhoof, Clifton Burt, Todd Hawbaker
Efficient delineation of nested depression hierarchy in digital elevation models for hydrological analysis using level-set method
In terrain analysis and hydrological modeling, surface depressions (or sinks) in a digital elevation model (DEM) are commonly treated as artifacts and thus filled and removed to create a depressionless DEM. Various algorithms have been developed to identify and fill depressions in DEMs during the past decades. However, few studies have attempted to delineate and quantify the nested hierarchy of ac
Authors
Qiusheng Wu, Charles R. Lane, Lei Wang, Melanie K. Vanderhoof, Jay R. Christensen, Hongxing Liu
Interpretation of low‐temperature thermochronometer ages from tilted normal fault blocks
Low‐temperature thermochronometry is widely used to measure the timing and rate of slip on normal faults. Rates are often derived from suites of footwall thermochronometer samples, but regression of age vs. structural depth fails to account for the trajectories of samples during fault slip. We demonstrate that in rotating fault blocks, regression of age‐depth data is susceptible to significant err
Authors
Samuel Johnstone, Joseph Colgan