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Mary McGann

Research Geologist at the USGS Pacific Coastal and Marine Science Center

Science and Products

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View from the sky looking at mouth of river with lots of sediment deposited at a beach.

Sediment Transport in Coastal Environments

Our research goals are to provide the scientific information, knowledge, and tools required to ensure that decisions about land and resource use, management practices, and future development in the coastal zone and adjacent watersheds can be evaluated with a complete understanding of the probable effects on coastal ecosystems and communities, and a full assessment of their vulnerability to natural...
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Sediment Lab Suite and Carbon Analysis Laboratory, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
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Sediment Transport in Coastal Environments

Our research goals are to provide the scientific information, knowledge, and tools required to ensure that decisions about land and resource use, management practices, and future development in the coastal zone and adjacent watersheds can be evaluated with a complete understanding of the probable effects on coastal ecosystems and communities, and a full assessment of their vulnerability to natural...
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Grid of photomicrographs and sketches of foraminifera.

Transport of invasive microorganisms

The objectives of his project are to investigate the vectors and timing of microbiological invasions and the subsequent dispersal of these non-native organisms due to sediment transport. We will attempt to confirm the identification of specific invasives encountered with molecular sequencing, monitor the spread of the invading populations through their recent distribution and the historic...
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Transport of invasive microorganisms

The objectives of his project are to investigate the vectors and timing of microbiological invasions and the subsequent dispersal of these non-native organisms due to sediment transport. We will attempt to confirm the identification of specific invasives encountered with molecular sequencing, monitor the spread of the invading populations through their recent distribution and the historic...
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A building after an earthquake has crumbled the roof and brick walls, the interior is now visible.

U.S. West Coast and Alaska Marine Geohazards

Marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, 3-D CT Core Imaging Laboratory, Core Preparation and Analysis Laboratory and Sample Repositories, Big Sur Landslides, Deep Sea Exploration, Mapping and Characterization, Subduction Zone Science
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U.S. West Coast and Alaska Marine Geohazards

Marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.
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Grain-size data from core S3-15G, Monterey Fan, Central California

This data release supersedes version 1.0, published in October 2021 at https://doi.org/10.5066/F74F1NW7. Versioning details are documented in the accompanying VersionHistory_P9DZ321R.txt file.  This data release presents sediment grain-size data from samples collected from core S3-15G, a 4.72-m long gravity core collected at a depth of 3,491 meters on the western levy of the Monterey Fan on May 3
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Pacific Coastal and Marine Science Center

Census counts of benthic foraminifera, environmental parameters (temperature, salinity, and oxygen concentration), and radiocarbon measurements from cores obtained under and near a whale-fall off western Vancouver Island, British Columbia, Canada

This data release provides census counts of benthic foraminifera (in percent for the total fauna and as raw counts for just the living specimens) as well as environmental parameters (temperature, salinity, and oxygen concentration) at the sampling sites, and radiocarbon measurements from selected push core samples obtained under and near a whale-fall off western Vancouver Island, British Columbia,
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Grain-size data from core S3-15G, Monterey Fan, Central California

This data release presents sediment grain-size data from samples collected from core S3-15G, a 4.72-m long gravity core collected at a depth of 3,491 meters on the western levy of the Monterey Fan on May 31, 1978 (USGS Field Activity S-3-78-SC).
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Deep Sea Exploration, Mapping and Characterization

Geophysical properties, geochronologic, and geochemical data of sediment cores collected from San Pablo Bay, California, October 17-20, 2016

Geophysical properties (P-wave velocity, gamma ray density, and magnetic susceptibility), geochronologic (radiocarbon, excess Lead-210, and Cesium-137), and geochemical data (organic carbon content and 60 element contents) are reported for select vibracores collected aboard the S/V Retriever October 17-20, 2016 in San Pablo Bay, California. Geophysical properties were measured with a Geotek Multi-
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Multi-Sensor Core Logger Laboratory, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Donated ROV vibracore and sampling data collected during Monterey Bay Aquarium Research Institute cruises in 2019 offshore of south-central California

This dataset includes photographs of vibracores that were collected by the Monterey Bay Aquarium Research Institute (MBARI) in February 2019 and November 2019 aboard the R/V Western Flyer using the remotely operated vehicle (ROV) Doc Ricketts. The collection of these cores was funded entirely by MBARI, and the cores have been donated to the U.S. Geological Survey (USGS). The cores were collected i
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory, Deep Sea Exploration, Mapping and Characterization

Sediment core data from the northern flank of Monterey Canyon, offshore California

The five files included in this U.S. Geological Survey data release are data from a set of sediment cores acquired from the continental slope, north of Monterey Canyon, offshore central California. Vibracores and push cores were collected with the Monterey Bay Aquarium Research Institutes remotely operated vehicle (ROV) Doc Ricketts in 2014 (cruise ID 2014-615-FA). One spreadsheet (NorthernFlankMo
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory

Sediment core data from offshore Palos Verdes, California

The seven files included in this U.S. Geological Survey data release are data from a set of sediment cores acquired from the continental slope, offshore Los Angeles and the Palos Verdes Peninsula, adjacent to the Palos Verdes Fault. Gravity cores were collected by the USGS in 2009 (cruise ID S-I2-09-SC; http://cmgds.marine.usgs.gov/fan_info.php?fan=SI209SC), and vibracores were collected with the
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory
Grid of photomicrographs and sketches of foraminifera.
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Filter Total Items: 62

The invasive Asian benthic foraminifera Trochammina hadai Uchio, 1962: Identification of a new local in Normandy (France) and a discussion on its putative introduction pathways

The invasive benthic foraminifera Trochammina hadai has been found for the first time in Europe along the coast of Normandy. Its native range of distribution is in Asia (Japan and Korea), and it has also been introduced along the coasts of western North America, Brazil and Australia. Morphological and molecular assessments confirm that specimens found in Le Havre and Caen-Ouistreham harbors belong
Authors
Vincent M.P. Bouchet, Jean-Charles Pavard, Maria Holzmann, Mary McGann, Eric Armynot de Chatelet, Apolyne Courleux, Jean-Phillipe Pezy, Jean-Claude Dauvin, Laurent Seuront
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Pacific Coastal and Marine Science Center

Sediment gravity flow frequency offshore central California diminished significantly following the Last Glacial Maximum

A high-resolution multibeam survey from a portion of the San Simeon Channel (offshore Morro Bay, California) captured a zone of recurring troughs and ridges adjacent to prominent submarine meander bends. Through an integrated study using surveying data, sediment core analysis, radiocarbon dating, and stable isotope measurements, we hypothesize that turbidity current event frequency was higher duri
Authors
Stephen C. Dobbs, Charles K. Paull, Eve M. Lundsten, Roberto Gwiazda, David W. Caress, Mary McGann, Marianne M. Coholich, Maureen A.L. Walton, Nora Maria Nieminski, Timothy McHargue, Steven A. Graham
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Pacific Coastal and Marine Science Center

The San Francisco Estuary, USA as a reference section for an Anthropocene series

A San Francisco Estuary core was analysed at high resolution to assess its component stratigraphic signatures of the Anthropocene in the form of non-native species, Hg, spheroidal carbonaceous particles, δ13Corg, δ15N, radiogenic materials, and heavy metals. Time series analysis of the core using Ti data provides a chronology to depth 167 cm into the 1960s. Below this, to depth 230 cm, the lowermo
Authors
Stephen J Himson, Mark A. Williams, Jan Zalasiewicz, Colin N. Waters, Mary McGann, Richard England, Bruce E. Jaffe, Arnoud Boom, Rachael Holmes, Sue Sampson, Cerin Pye, Juan Carlos Berrio, Genevieve Tyrrell, Ian P. Wilkinson, Neil Rose, Pawel Gaca, Andrew Cundy
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Pacific Coastal and Marine Science Center

Affinity of the benthic foraminifer Cassidulinoides parkeriana (Brady) for whale-falls: Evidence from off western Vancouver Island, British Columbia, Canada

A partial skeleton of a blue or fin whale, estimated to have been 16.5 m in length and thought to have been lying on the seafloor for less than 10 years, was observed at a depth of 1288 m off western Vancouver Island, British Columbia, Canada (48.68° N, 126.84° W). Four push cores were taken at the site, three (15-26 cm in length) directly under caudal vertebrae and one 18 cm long, considered a re
Authors
Mary McGann, Charles K. Paull
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Pacific Coastal and Marine Science Center

Planetary-scale change to the biosphere signalled by global species translocations can be used to identify the Anthropocene

We examine three distinctive biostratigraphic signatures associated with: hunting and gathering, landscape domestication, and globalisation. All three signatures have significant fossil records of regional importance that can be correlated inter-regionally and help describe the developing pattern of human expansion and appropriation of resources. While none have individual first or last appearance
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Mark A. Williams, Reinhold Leinfelder, Anthony D. Barnosky, Martin J Head, Francine M G McCarthy, Cearreta. Alejandro, Stephen J Himson, Rachael Holmes, Colin N. Waters, Jan Zalasiewicz, Simon Turner, Mary McGann, Elizabeth A. Hadly, M. Allison Stegner, Paul Michael Pilkington, Jérôme Kaiser, Juan Carlos Berrio, Ian P. Wilkinson, Jens Zinke, Kristine L. DeLong
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Pacific Coastal and Marine Science Center

Impact of climate change on mollusks and other invertebrate resources at the Dominican University of California archaeological site (CA-MRN-254), Marin County, California

We have identified and provided ecological interpretations of 30 taxa recovered at two shellmounds at the Dominican University of California archaeology site in Marin County, California (CA-MRN-254). A Q-mode cluster analysis was used to group the samples according to their faunal similarity. The clusters ranged from a diverse grouping of 100 samples with 27 taxa (Cluster A) to those with a more r
Authors
Mary McGann, Charles L. Powell
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Coastal and Marine Hazards and Resources Program, Geology, Minerals, Energy, and Geophysics Science Center, Pacific Coastal and Marine Science Center

Marine paleoseismic evidence for seismic and aseismic slip along the Hayward-Rodgers Creek fault system in northern San Pablo Bay

Distinguishing between seismic and aseismic fault slip in the geologic record is difficult, yet fundamental to estimating the seismic potential of faults and the likelihood of multi-fault ruptures. We integrated chirp sub-bottom imaging with targeted cross-fault coring and core analyses of sedimentary proxy data to characterize vertical deformation and slip behavior within an extensional fault ben
Authors
Janet Watt, Mary McGann, Renee K. Takesue, Thomas Lorenson
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory

Potential use of the benthic foraminifers Bulimina denudata and Eggerelloides advenus in marine sediment toxicity testing

The benthic foraminifers Bulimina denudata and Eggerelloides advenus are commonly abundant in offshore regions in the Pacific Ocean, especially in waste-discharge sites. The relationship between their abundance and standard macrofaunal sediment toxicity tests (amphipod survival and sea urchin fertilization) as well as sediment chemistry analyte measurements were determined for sediments collected
Authors
Mary McGann
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Preconditioning by sediment accumulation can produce powerful turbidity currents without major external triggers

Turbidity currents dominate sediment transfer into the deep ocean, and can damage critical seabed infrastructure. It is commonly inferred that powerful turbidity currents are triggered by major external events, such as storms, river floods, or earthquakes. However, basic models for turbidity current triggering remain poorly tested, with few studies accurately recording precise flow timing. Here, w
Authors
Lewis Bailey, Michael Clare, Kurt J. Rosenberger, Matthieu J.B. Cartigny, Peter J. Talling, Charles K. Paull, Roberto Gwiazda, Daniel Parsons, Stephen Simmons, Jingping Xu, Ivan Haigh, Katherine L. Maier, Mary McGann, Eve M. Lundsten
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)

Fluid seepage along obliquely deforming plate boundaries can be an important indicator of crustal permeability and influence on fault-zone mechanics and hydrocarbon migration. The ~850-km-long Queen Charlotte fault (QCF) is the dominant structure along the right-lateral transform boundary that separates the Pacific and North American tectonic plates offshore southeastern Alaska (USA) and western B
Authors
Nancy G. Prouty, Daniel S. Brothers, Jared W. Kluesner, J. Vaughn Barrie, Brian D. Andrews, Rachel Lauer, Gary Greene, James E. Conrad, Thomas Lorenson, Michael D. Law, Diana Sahy, Kim Conway, Mary McGann, Peter Dartnell
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Deep Sea Exploration, Mapping and Characterization

What determines the downstream evolution of turbidity currents?

Seabed sediment flows called turbidity currents form some of the largest sediment accumulations, deepest canyons and longest channel systems on Earth. Only rivers transport comparable sediment volumes over such large areas; but there are far fewer measurements from turbidity currents, ensuring they are much more poorly understood. Turbidity currents differ fundamentally from rivers, as turbidity c
Authors
Catharina Heerema, Peter J. Talling, Matthieu J.B. Cartigny, Charles K. Paull, Lewis Bailey, Stephen Simmons, Daniel Parsons, Michael Clare, Roberto Gwiazda, Eve M. Lundsten, Krystle Anderson, Katherine L. Maier, Jingping Xu, Esther J. Sumner, Kurt J. Rosenberger, Jenny Gales, Mary McGann, Lionel Carter, Ed Pope
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Shallow-water foraminifera and other microscopic biota of Clipperton Island, tropical eastern Pacific

The recent foraminiferal fauna and associated microbiota of Clipperton Island (10.2833°N, 109.2167°W) were investigated at 20 sites collected in the intertidal zone around the perimeter of the island and from the edge of the inner brackish-water lagoon. Due to the island’s geographic location in a low productivity zone, a lack of variable habitats on and surrounding the island, and heavy surf that
Authors
Mary McGann, Robert W Schmieder, Louis-Philippe Loncke
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Science and Products