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A review of common natural disasters as analogs for asteroid impact effects and cascading hazards
Modern civilization has no collective experience with possible wide-ranging effects from a medium-sized asteroid impactor. Currently, modeling efforts that predict initial effects from a meteor impact or airburst provide needed information for initial preparation and evacuation plans, but longer-term cascading hazards are not typically considered. However, more common natural disasters, such as vo
Authors
Timothy N. Titus, D. G. Robertson, Joel B. Sankey, Larry G. Mastin, Francis K. Rengers
From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence
In the long-term absence of disturbance, ecosystems often enter a decline or retrogressive phase which leads to reductions in primary productivity, plant biomass, nutrient cycling and foliar quality. However, the consequences of ecosystem retrogression for higher trophic levels such as herbivores and predators, are less clear. Using a post-fire forested island-chronosequence across which retrogres
Authors
Anne Kempel, Eric Allan, Martin M. Gossner, Malte Jochum, James Grace, David A. Wardle
Six years of fluvial response to a large dam removal on the Carmel River, California, USA
Measuring river response to dam removal affords a rare, important opportunity to study fluvial response to sediment pulses on a large field scale. We present a before–after/control–impact study of the Carmel River, California, measuring fluvial geomorphic and grain-size evolution over 8 years, six of which postdated removal of a 32 m-high dam (one of the largest dams removed worldwide) and include
Authors
Amy E. East, Lee R. Harrison, Douglas P. Smith, Joshua B. Logan, Rosealea Bond
Increasing Alaskan river discharge during the cold season is driven by recent warming
Arctic hydrology is experiencing rapid changes including earlier snow melt, permafrost degradation, increasing active layer depth, and reduced river ice, all of which are expected to lead to changes in stream flow regimes. Recently, long-term (>60 years) climate reanalysis and river discharge observation data have become available. We utilized these data to assess long-term changes in discharge an
Authors
D Blaskey, Joshua C. Koch, M. Gooseff, A. C. Newman, Yang Cheng, Jonathan A. O'Donnell, K Musselman
Upwelling, climate change, and the shifting geography of coral reef development
The eastern tropical Pacific is oceanographically unfavorable for coral-reef development. Nevertheless, reefs have persisted there for the last 7000 years. Rates of vertical accretion during the Holocene have been similar in the strong-upwelling Gulf of Panamá (GoP) and the adjacent, weak-upwelling Gulf of Chiriquí (GoC); however, seasonal upwelling in the GoP exacerbated a climate-driven hiatus i
Authors
Victor Rodriguez-Ruano, Lauren Toth, Ian C. Enochs, Carly J. Randall, Richard B. Aronson
Detection and monitoring of small-scale diamond and gold mining dredges using synthetic aperture radar on the Kadéï (Sangha) River, Central African Republic
Diamond and gold mining has been practiced by artisanal miners in the Central African Republic (CAR) for decades. The recent introduction of riverine dredges indicates a transition from artisanal/manual digging and sorting techniques to small-scale mining methods. This study implements a remote sensing analysis of Synthetic Aperture Radar (SAR) data to map gold and diamond dredges operating on the
Authors
Marissa Ann Alessi, Peter G. Chirico, Sindhuja Sunder, Kelsey L. O'Pry
Stabilising effects of karstic groundwater on stream fish communities
Although groundwater exchange processes are known to modulate atmospheric influences on stream temperature and flow, the implications for ecological stability are poorly understood. Here, we evaluated temporal change in stream fish communities across a gradient of groundwater influence defined by karst terrain (carbonate parent materials) within the Potomac River basin of eastern North America. We
Authors
Nathaniel Hitt, Karli M Rogers, Karmann G. Kessler, Martin Briggs, Jennifer Burlingame Hoyle Fair
Sierra Nevada amphibians demonstrate stable occupancy despite precipitation volatility in the early 21st Century
Climate can have a strong influence on species distributions, and amphibians with different life histories might be affected by annual variability in precipitation in different ways. The Sierra Nevada of California, United States, experienced some of the driest and wettest years on record in the early 21st Century, with variability in annual precipitation predicted to increase with climate change.
Authors
Brian J. Halstead, Patrick M. Kleeman, Jonathan P. Rose, Gary M. Fellers
When less is more: How increasing the complexity of machine learning strategies for geothermal energy assessments may not lead toward better estimates
Previous moderate- and high-temperature geothermal resource assessments of the western United States utilized data-driven methods and expert decisions to estimate resource favorability. Although expert decisions can add confidence to the modeling process by ensuring reasonable models are employed, expert decisions also introduce human and, thereby, model bias. This bias can present a source of err
Authors
Stanley Paul Mordensky, John Lipor, Jacob DeAngelo, Erick R. Burns, Cary Ruth Lindsey
Regolith of the crater floor units, Jezero crater, Mars: Textures, composition and implications for provenance
A multi-instrument study of the regolith of Jezero crater floor units by the Perseverance rover has identified three types of regolith: fine-grained, coarse-grained, and mixed-type. Mastcam-Z, WATSON, and SuperCam RMI were used to characterize regolith texture, particle size, and roundedness where possible. Mastcam-Z multispectral and SuperCam LIBS data were used to constrain the composition of th
Authors
Alicia Vaughan, Michelle E. Minitti, Emily L. Cardarelli, Jeffrey R. Johnson, Linda C. Kah, Paolo Pilleri, Mellisa S. Rice, Mark Sephton, Briony H. N. Horgan, Roger C. Wiens, R. Aileen Yingst, Maria-Paz Zorzano Mier, Ryan Anderson, James F. III Bell, Adrian J. Brown, Edward A. Cloutis, Agnes Cousin, Kenneth E. Herkenhoff, Elisabeth M. Housrath, Alexander G. Hayes, Kjartan M. Kinch, Marco Merusi, Chase C. Million, Robert Sullivan, Sandra M. Siljestrom, Michael St. Clair
Groundwater quality near the Montebello Oil Field, Los Angeles County, California
Groundwater quality and potential sources and migration pathways of chemical constituents associated with hydrocarbon-bearing formations were assessed by the U.S. Geological Survey for the California State Water Resources Control Board Oil and Gas Regional Monitoring Program (RMP). Groundwater samples were collected as part of the RMP from 21 preexisting wells used for public supply, monitoring, o
Authors
Jennifer S. Stanton, Michael Land, Matthew K. Landon, David H. Shimabukuro, Peter B. McMahon, Tracy A. Davis, Andrew G. Hunt, Theron A. Sowers
Ice and ocean constraints on early human migrations into North America along the Pacific Coast
Founding populations of the first Americans likely occupied parts of Beringia during the Last Glacial Maximum (LGM). The timing, pathways, and modes of their southward transit remain unknown, but blockage of the interior route by North American ice sheets between ~26 and 14 cal kyr BP (ka) favors a coastal route during this period. Using models and paleoceanographic data from the North Pacific, we
Authors
Summer K. Praetorius, Jay R. Alder, Alan Condron, Alan Mix, Maureen Walczak, Beth Elaine Caissie, Jon Erlandson