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Publications

Scientific reports, journal articles, and information products produced by USGS Pacific Coastal and Marine Science Center scientists.

Filter Total Items: 1331

Cohesive sediment modeling in a shallow estuary: Model and environmental implications of sediment parameter variation

Numerical models of sediment transport in estuarine systems rely on parameter values that are often poorly constrained and can vary on timescales relevant to model processes. The selection of parameter values can affect the accuracy of model predictions, while environmental variation of these parameters can impact the temporal and spatial ranges of sediment fluxes, erosion, and deposition in the r

Authors
Rachel Allen, Jessica R. Lacy, Andrew W. Stevens

Miocene phosphatization of rocks from the summit of Rio Grande Rise, Southwest Atlantic Ocean

Marine phosphorites are an important part of the oceanic phosphorus cycle and are related to the effects of long-term global climate changes. We use petrography, mineralogy, rare earth elements contents, and 87Sr/86Sr-determined carbonate fluorapatite (CFA) and calcite ages to investigate the paragenesis and history of phosphatization of carbonate sediments, limestones, ferromanganese crusts, and
Authors
Mariana Benites, James R. Hein, Kira Mizell, Luigi Jovane

Multiple climate change-driven tipping points for coastal systems

As the climate evolves over the next century, the interaction of accelerating sea level rise (SLR) and storms, combined with confining development and infrastructure, will place greater stresses on physical, ecological, and human systems along the ocean-land margin. Many of these valued coastal systems could reach “tipping points,” at which hazard exposure substantially increases and threatens the
Authors
Patrick L. Barnard, Jenifer Dugan, Henry M. Page, Nathan J. Wood, Juliette A. Finzi Hart, Daniel Cayan, Li H. Erikson, David A. Hubbard, Monique Myers, John M. Melack, Samuel F. Iacobellis

Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds

Deep-sea polymetallic nodule mining research activity has substantially increased in recent years, but the expected level of environmental impact is still being established. One environmental concern is the discharge of a sediment plume into the midwater column. We performed a dedicated field study using sediment from the Clarion Clipperton Fracture Zone. The plume was monitored and tracked using
Authors
Carlos Munoz-Royo, Thomas Peacock, Matthew Alford, Jerome Smith, Arnaud Le Boyer, Chinmay Kulkarni, Pierre Lermusiaux, Patrick Haley, C Mirabito, Dayang Wang, Eric Adams, Raphael Ouillon, Alexander Breugem, Boudewijn Decrop, Thijs Lanckreit, Rohit Supekar, Andrew Rzeznik, Amy Gartman, Se-Jong Ju

Multiple melt source origin of the Line Islands (Pacific Ocean)

The Line Islands volcanic chain in the central Pacific Ocean exhibits many characteristics of a hotspot-generated seamount chain; however, the lack of a predictable age progression has stymied previous models for the origin of this feature. We combined plate-tectonic reconstructions with seamount age dates and available geochemistry to develop a new model that involves multiple melt regions and mu
Authors
Robert Pockalny, Ginger Barth, Barry Eakins, Katherine A. Kelley, Christina Wertman

Bomb-produced radiocarbon across the South Pacific Gyre — A new record from American Samoa with utility for fisheries science

Coral skeletal structures can provide a robust record of nuclear bomb produced 14C with valuable insight into air-sea exchange processes and water movement with applications to fisheries science. To expand these records in the South Pacific, a coral core from Tutuila Island, American Samoa was dated with density band counting covering a 59-yr period (1953–2012). Seasonal signals in elemental ratio
Authors
Allen Andrews, Nancy G. Prouty, Olivia Cheriton

Global-scale changes to extreme ocean wave events due to anthropogenic warming

Extreme surface ocean waves are often primary drivers of coastal flooding and erosion over various time scales. Hence, understanding future changes in extreme wave events owing to global warming is of socio-economic and environmental significance. However, our current knowledge of potential changes in high-frequency (defined here as having return periods of less than 1 year) extreme wave events ar
Authors
Joao Morim, Sean Vitousek, Mark Hemer, Borja Reguero, Li H. Erikson, Merce Casas-Prat, Xiaolan L. Wang, Alvaro Semedo, Nobuhito Mori, Tomoya Shimura, Lorenzo Mentaschi, Ben Timmerman

Timing of iceberg scours and massive ice-rafting events in the subtropical North Atlantic

High resolution seafloor mapping shows extraordinary evidence that massive (>300 m thick) icebergs once drifted >5,000 km south along the eastern United States, with >700 iceberg scours now identified south of Cape Hatteras. Here we report on sediment cores collected from several buried scours that show multiple plow marks align with Heinrich Event 3 (H3), ~31,000 years ago. Numerical glacial iceb
Authors
Alan Condron, Jenna C. Hill

Influence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system

We present a field study combining measurements of vegetation density, vegetative drag, and reduction of suspended-sediment concentration (SSC) within patches of the invasive submerged aquatic plant Egeria densa. Our study was motivated by concern that sediment trapping by E. densa, which has proliferated in the Sacramento–San Joaquin Delta, is impacting marsh accretion and reducing turbidity. In

Authors
Jessica R. Lacy, Madeline R. Foster-Martinez, Rachel M. Allen, Judith Z. Drexler

Twenty-first-century projections of shoreline change along inlet-interrupted coastlines

Sandy coastlines adjacent to tidal inlets are highly dynamic and widespread landforms, where large changes are expected due to climatic and anthropogenic influences. To adequately assess these important changes, both oceanic (e.g., sea-level rise) and terrestrial (e.g., fluvial sediment supply) processes that govern the local sediment budget must be considered. Here, we present novel projections o
Authors
Janaka Bamunawala, Roshanka Ranasinghe, Ali Dastgheib, Robert .J. Nichols, A. Brad Murray, Patrick L. Barnard, T. A. J. G. Sirisena, Trang Minh Duong, Suzanne J. M. H. Hulscher, Ad van der Spek

Point clouds of bridge generated by terrestrial laser scanner and images via Structure from Motion technique: Comparison study

A collection of points representing an object in space is commonly called a point cloud. There are several techniques for collecting point clouds. This research is focused on a comparison study of two approaches: (1) collecting point clouds with a surveying grade terrestrial laser scanner (TLS) and (2) generating point clouds from drone-taken still images by utilizing Structure-from-Motion (SFM) t
Authors
Shakzod Takhirov, Robert E. Kayen

New geochemical tools for investigating resource and energy functions at deep-sea cold seeps using amino-acid δ15N in chemosymbiotic mussels (Bathymodiolus childressi)

In order to reconstruct the ecosystem structure of chemosynthetic environments in the fossil record, geochemical proxies must be developed. Here, we present a suite of novel compound-specific isotope parameters for tracing chemosynthetic production with a focus on understanding nitrogen dynamics in deep-sea cold seep environments. We examined the chemosymbiotic bivalve Bathymodiolus childressi fro
Authors
Natasha Vokhshoori, Matt McCarthy, Hilary Close, Amanda Demopoulos, Nancy G. Prouty