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Coral reefs and their ecosystems are threatened by both global stressors, including increasing sea-surface temperatures and ocean acidification (OA), and local stressors such as land-based sources of pollution that can magnify the effects of OA. Corals can physiologically control the chemistry of their internal calcifying fluids (CF) and can thereby regulate their calcification process. Specifical
Authors
Nancy G. Prouty, Marlene Wall, J. Fietzke, Olivia Cheriton, Eleni Anagnostou, Brian Phillip, Adina Paytan
Saline tidal wetlands are important sites of carbon sequestration and produce negligible methane (CH4) emissions due to regular inundation with sulfate-rich seawater. Yet, widespread management of coastal hydrology has restricted tidal exchange in vast areas of coastal wetlands. These ecosystems often undergo impoundment and freshening, which in turn cause vegetation shifts like invasion by Phragm
Authors
Rebecca Sanders-DeMott, Meagan J. Eagle, Kevin D. Kroeger, Faming Wang, Thomas W. Brooks, Jennifer A. O'Keefe Suttles, Sydney K. Nick, Adrian G. Mann, Jianwu Tang
Erosion rates along Alaska's Beaufort Sea coast, among the highest in the world, are negatively impacting communities, industrial and military infrastructure, and wildlife habitat. Decreasing maximal winter ice extent and increasing summer open water duration and extent in the Beaufort Sea may be making the coast more vulnerable to destructive storm waves than during recent, colder, icier decades.
Authors
Mark Zimmermann, Li H. Erikson, Ann E. Gibbs, Megan M. Prescott, Stephen M. Escarzaga, Craig E. Tweedie, Jeremy L. Kasper, Paul X. Duvoy
Producing accurate hindcasts and forecasts with coupled models is challenging due to complex parameterizations that are difficult to ground in observational data. We present a calibration workflow that utilizes a series of machine learning algorithms paired with Windsurf, a coupled beach-dune model (Aeolis, the Coastal Dune Model, and XBeach), to produce hindcasts and forecasts of morphologic chan
Authors
Michael Christopher Itzkin, Laura J. Moore, Peter Ruggiero, Paige A. Hovenga, Sally D. Hacker
Identifying relatively intact areas within ecosystems and determining the conditions favoring their existence is necessary for effective management in the context of widespread environmental degradation. In this study, we used 3766 surveys of randomly selected sites in the United States and U.S. Territories to identify the correlates of sites categorized as “oases” (defined as sites with relativel
Authors
Robin Elahi, Peter J. Edmunds, Ruth D. Gates, Ilsa B. Kuffner, Brian B. Barnes, Iliana Chollett, Travis A. Courtney, James R. Guest, Elizabeth A. Lenz, Lauren Toth, T. Shay Viehman, Ivor D. Williams
Rates of shoreline change have been updated for the open-ocean sandy coastlines of Georgia and Florida as part of the U.S. Geological Survey’s Coastal Change Hazards programmatic focus. This work was formerly within the National Assessment of Shoreline Change project. Shorelines were compiled from the original report published in 2005, recent update reports, and additional light detection and rang
This work experimentally explores porosity, compressibility, and the ratio of horizontal to vertical effective stress (K0) in hydrate-bearing sandy silts from Green Canyon Block 955 in the deep-water Gulf of Mexico. The samples have an in situ porosity of 0.38 to 0.40 and a hydrate saturation of more than 80%. The hydrate-bearing sediments are stiffer than the equivalent hydrate-free sediments; th
Authors
Yi Fang, Peter Flemings, John Germaine, Hugh Daigle, Stephen C. Phillips, Joshua O'Connell
Permeability is one of the most crucial properties governing fluid flow in methane hydrate reservoirs. This paper presents a comprehensive permeability analysis of hydrate-bearing sandy silt pressure-cored from Green Canyon Block 955 (GC 955) in the deep-water Gulf of Mexico. We developed an experimental protocol to systematically characterize the transport and petrophysical properties in pressure
Authors
Yi Fang, Peter Flemings, Hugh Daigle, Stephen C. Phillips, Joshua O'Connell
Massive volumes of gas are sequestered within gas hydrate in subsurface marine sediments in the Gulf of Mexico. Methane associated with gas hydrate is a potentially important economic resource and a significant reservoir of carbon within the global carbon cycle. Nevertheless, uncertainties remain about the genetic source (e.g., microbial, thermogenic) and possible migration history of natural gas
Authors
Myles T. Moore, Stephen C. Phillips, Ann Cook, Thomas H. Darrah
Effective management and restoration of salt marshes and other vegetated intertidal habitats require objective and spatially integrated metrics of geomorphic status and vulnerability. The unvegetated-vegetated marsh ratio (UVVR), a recently developed metric, can be used to establish present-day vegetative cover, identify stability thresholds, and quantify vulnerability to open-water conversion ove
Authors
Neil K. Ganju, Brady Couvillion, Zafer Defne, Kate Ackerman
Our understanding of the up to 7 orders of magnitude partitioning of thallium (Tl) between seawater and ferromanganese (FeMn) deposits rests upon two foundations: (1) being able to quantify the Tl(I)/Tl(III) ratio that reflects the extent of the oxidative scavenging of Tl by vernadite (δ-MnO2), the principle manganate mineral in oxic and suboxic environments, and (2) being able to determine the so
Authors
Alain Manceau, Alexandre Simionovici, Nathaniel Findling, Pieter Glatzel, Blanka Detlefs, Anna V Wegorzewski, Kira Mizell, James R. Hein, Andrea Koschinsky
Barkley Canyon is one of the few known sites worldwide with the occurrence of thermogenic gas seepage and formation of structure-II and structure-H gas hydrate mounds on the seafloor. This site is the location of continuous seafloor monitoring as part of the Ocean Networks Canada (ONC) cabled observatory off the west coast off Vancouver Island, British Columbia, Canada. We combine repeat remotely
Authors
M. Reidel, M. Scherwath, M. Romer, C. K. Paull, E. Lundsten, D. W. Caress, P. Brewer, John Pohlman, L. L. Lapham, N. R. Chapman, M. Whiticar, G. D. Spence, R. Enkin, K. Douglas