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Guy Gelfenbaum

Oceanographer Emeritus with the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California

Ecosystem Dynamics, Project Chief: Coastal Habitats in Puget Sound - The goal of these projects is to develop scientific information and tools to support natural resource managers in the adaptive management of critical nearshore ecosystems in Puget Sound

Large-Scale Coastal Change, Project Chief: Southwest Washington Coastal Erosion Study - Research involves understanding complex relationships among sediment supply, littoral processes, and shoreline erosion or accretion in a high-energy coastal environment.  Studies encompass multiple time and space scales of coastal evolution, and successfully differentiate natural and anthropogenic influences on coastal change.

Catastrophic Geologic Hazards, Co-Principal Investigator: Tsunami Hazards Study - Research effort to improve our understanding of tsunami hazards through identification and interpretation of sediments deposited from tsunamis

Professional Experience

  • 2022: Oceanographer Emeritus, Pacific Coastal and Marine Science Center

  • 2017-2021: Center Director, Pacific Coastal and Marine Science Center

Education and Certifications

  • 1988 Ph.D. Geological Oceanography - University of Washington, Seattle

  • 1982 M.S. Geological Oceanography - University of Washington, Seattle

  • 1978 B.S. Geology - University of Wisconsin, Madison

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, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Sediment Lab Suite and Carbon Analysis Laboratory
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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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An estuary with many channels widening towards the sea through lush forests and grasslands, village in distance.

Columbia River estuary

This research is part of the project “Sediment Transport in Coastal Environments.” We aim to support regional sediment management in the Columbia River littoral cell by monitoring and modeling shoreline change, modeling fate of disposed dredged material, and studying bedform morphology.
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Columbia River estuary

This research is part of the project “Sediment Transport in Coastal Environments.” We aim to support regional sediment management in the Columbia River littoral cell by monitoring and modeling shoreline change, modeling fate of disposed dredged material, and studying bedform morphology.
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A home, severely damaged by the tsunami that hit Sumatra on December 26, 2004, sits atop debris.

Tsunami Hazards, Modeling, and the Sedimentary Record

Basic research to develop the geologic record of paleotsunamis and improve the ability to interpret that record is needed to mitigate tsunami risk in the U.S.
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Natural Hazards, 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, Multi-Sensor Core Logger Laboratory, Sediment Lab Suite and Carbon Analysis Laboratory
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Tsunami Hazards, Modeling, and the Sedimentary Record

Basic research to develop the geologic record of paleotsunamis and improve the ability to interpret that record is needed to mitigate tsunami risk in the U.S.
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Illustration showing an oblique view of the Puget Sound watershed.

Estuaries and large river deltas in the Pacific Northwest

Essential habitat for wild salmon and other wildlife borders river deltas and estuaries in the Pacific Northwest. These estuaries also support industry, agriculture, and a large human population that’s expected to double by the year 2060, but each could suffer from more severe river floods, higher sea level, and storm surges caused by climate change.
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Estuaries and large river deltas in the Pacific Northwest

Essential habitat for wild salmon and other wildlife borders river deltas and estuaries in the Pacific Northwest. These estuaries also support industry, agriculture, and a large human population that’s expected to double by the year 2060, but each could suffer from more severe river floods, higher sea level, and storm surges caused by climate change.
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Elwha River flowing through former Aldwell reservoir

USGS science supporting the Elwha River Restoration Project

The Elwha River Restoration Project has reconnected the water, salmon, and sediment of a pristine river and coast of the Olympic Peninsula of Washington.
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Ecosystems, Natural Hazards, Coastal and Marine Hazards and Resources Program, Fisheries Program (unpublished), Pacific Coastal and Marine Science Center
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USGS science supporting the Elwha River Restoration Project

The Elwha River Restoration Project has reconnected the water, salmon, and sediment of a pristine river and coast of the Olympic Peninsula of Washington.
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A man stands in water on a beach, holding a rod with a measurement ruler marked on it, near partially submerged tree stumps.

Tsunami Field Studies

Our tsunami scientists work on international teams to study the aftermath of tsunamis around the world, to gain a better understanding the impact of potential tsunamis on coastal communities of the United States. Their work helps inform local, state, and federal coastal planning, protection, and resiliency.
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Tsunami Field Studies

Our tsunami scientists work on international teams to study the aftermath of tsunamis around the world, to gain a better understanding the impact of potential tsunamis on coastal communities of the United States. Their work helps inform local, state, and federal coastal planning, protection, and resiliency.
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Graphic of waves breaking at the ocean surface with lettering below it for the coastal storm modeling system.

PS-CoSMoS FAQs

Puget Sound - Coastal Storm Modeling System (PS-CoSMoS) frequently asked questions

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PS-CoSMoS FAQs

Puget Sound - Coastal Storm Modeling System (PS-CoSMoS) frequently asked questions

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Three photos showing cross-sections of sand and labeled with various features to show the structure of tsunami deposits.

Preliminary Analysis of Sedimentary Deposits from the June 23, 2001 Peru Tsunami

A Cooperative Study by the USGS, la Dirección de Hidrografía y Navegación de la Marina de Guerra del Perú, Instituto Geofísico del Perú, Instituto Geologico, Minero y Metalurgico, University of California, Santa Cruz, University of Southern California, and University of San Agustin. September 4 - September 18, 2001
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Preliminary Analysis of Sedimentary Deposits from the June 23, 2001 Peru Tsunami

A Cooperative Study by the USGS, la Dirección de Hidrografía y Navegación de la Marina de Guerra del Perú, Instituto Geofísico del Perú, Instituto Geologico, Minero y Metalurgico, University of California, Santa Cruz, University of Southern California, and University of San Agustin. September 4 - September 18, 2001
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Small photo shows a man pointing to debris in the aftermath of a tsunami.

Preliminary Analysis of Sedimentary Deposits from the July 17, 1998 Papua New Guinea Tsunami

Preliminary analysis of sedimentary deposits from the tsunami caused by the July 17, 1998 Papua New Guinea earthquake.
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
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Preliminary Analysis of Sedimentary Deposits from the July 17, 1998 Papua New Guinea Tsunami

Preliminary analysis of sedimentary deposits from the tsunami caused by the July 17, 1998 Papua New Guinea earthquake.
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Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July 2018

Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system to changes
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Sediment Lab Suite and Carbon Analysis Laboratory

Beach topography and nearshore bathymetry of the Columbia River littoral cell, Washington and Oregon

This data release presents beach topography and nearshore bathymetry data from repeated surveys performed by a team of scientists from the U.S. Geological Survey, Washington State Department of Ecology, and Oregon State University in the Columbia River littoral cell (CRLC), Washington and Oregon. The CRLC extends approximately 165 kilometers between Point Grenville (PG), Washington, and Tillamook
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July 2017

Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system to changes
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Core logs, scans, photographs, grain size, and radiocarbon data from coastal wetlands on the Hawaiian islands of Kaua`i, O`ahu, and Hawai`i

Over the past 200 years of written records, the Hawaiian Islands have experienced tens of tsunamis generated by earthquakes in the subduction zones of the Pacific "Ring of Fire" (for example, Alaska-Aleutian, Kuril-Kamchatka, Chile, and Japan). Mapping and dating anomalous beds of sand and silt along the coasts of these subduction zones are critical for assessing the hazard from distant as well as
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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, Multi-Sensor Core Logger Laboratory, Sediment Lab Suite and Carbon Analysis Laboratory

Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Sediment Lab Suite and Carbon Analysis Laboratory

Oceanographic measurements and hydrodynamic modeling of the mouth of the Columbia River, Oregon and Washington, 2013

During May and June of 2013, the U.S. Geological Survey in collaboration with Naval Post-Graduate School, the University of Miami, and Deltares USA, participated in the Office of Naval Research-funded River and Inlets Dynamics (RIVET II) experiment to investigate the hydrodynamics of the mouth of the Columbia River (MCR). The field experiment consisted of the collection of continuous oceanographic
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, August 2012

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry and topography data from the Elwha River delta, Washington, May 2012

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry and topography data from the Elwha River delta, Washington, August 2011

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry and topography data from the Elwha River delta, Washington, May 2011

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry and topography data from the Elwha River delta, Washington, September 2010

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, March 2013

Two dams on the Elwha River, Washington State, USA trapped over 20 million cubic meters of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system
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Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
A man makes a gesture with his hand while standing at a podium in front of a microphone.
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View from the sky overlooking a severely flooded town with lingering pooled water and heavily damaged structures and roadways.
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A home, severely damaged by the tsunami that hit Sumatra on December 26, 2004, sits atop debris.
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Panoramic photo of Banda Aceh after the 2004 Sumatra earthquake and tsunami.
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Photograph of a boat washed up far inland in Banda Aceh after the December 26, 2004 Indian Ocean tsunami.
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Monitoring and modeling dispersal of a submerged nearshore berm at the mouth of the Columbia River, USA

A submerged, low-relief nearshore berm was constructed in the Pacific Ocean near the mouth of the Columbia River, USA, using 216,000 m3 of sediment dredged from the adjacent navigation channel. The material dredged from the navigation channel was placed on the northern flank of the ebb-tidal delta in water depths between 12 and 15 m and created a distinct feature that could be tracked over time. F
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Pacific Coastal and Marine Science Center

Can modeling the geologic record contribute to constraining the tectonic source of the AD 1755 Great Lisbon earthquake?

The precise location of the seismic source of 1755 CE Great Lisbon earthquake is still uncertain. The aim of this work is to use an onland sedimentary record in southern Portugal to test and validate seismic sources for the earthquake. To achieve this, tsunami deposit thicknesses from over 150 cores collected at Salgados in southern Portugal were compared to the results of a tsunami sediment trans
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Onshore flow characteristics of the 1755 CE Lisbon tsunami: Linking forward and inverse numerical modeling

The 1755 CE Lisbon earthquake triggered the largest historical tsunami ever impacting the Atlantic coasts of Europe. Despite recent efforts to better understand this event, there are still unanswered questions about the location of its epicenter and whether physical and historical evidences are in agreement.Inverse modeling using tsunami sediments can be applied to quantify onshore flow characteri
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Selective sediment transport during Hurricane Sandy on Fire Island (New York, USA): Inferences from heavy-mineral assemblages

In October 2012, Hurricane Sandy caused severe erosion on beaches and dunes of Fire Island (New York, USA). Major shoreline changes occurred with erosional dominance in the upper shoreline and aggradation in the lowermost section of the beach due to the deposition of eroded upper beach and dune sediment. Sand laminations with a high concentration of heavy minerals (“black sand laminations”) were o
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Observations of coastal change and numerical modeling of sediment-transport pathways at the mouth of the Columbia River and its adjacent littoral cell

Bathymetric and topographic surveys performed annually along the coastlines of northern Oregon and southwestern Washington documented changes in beach and nearshore morphology between 2014 and 2019. Volume change analysis revealed measurable localized erosion and deposition throughout the study area, but significant net erosion at the regional scale (several kilometers [km]) was limited to Benson
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

U.S. Geological Survey ecosystems science strategy—Advancing discovery and application through collaboration

Executive SummaryEcosystem science is critical to making informed decisions about natural resources that can sustain our Nation’s economic and environmental well-being. Resource managers and policymakers are faced with countless decisions each year at local, regional, and national levels on issues as diverse as renewable and nonrenewable energy development, agriculture, forestry, water supply, and
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Ecosystems

World’s largest dam removal reverses coastal erosion

Coastal erosion outpaces land generation along many of the world’s deltas and a significant percentage of shorelines, and human-caused alterations to coastal sediment budgets can be important drivers of this erosion. For sediment-starved and erosion-prone coasts, large-scale enhancement of sediment supply may be an important, but poorly understood, management option. Here we provide new topographi
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Evidence for frequent, large tsunamis spanning locked and creeping parts of the Aleutian megathrust

At the eastern end of the 1957 Andreanof Islands magnitude-8.6 earthquake rupture, Driftwood Bay (Umnak Island) and Stardust Bay (Sedanka Island) lie along presently locked and creeping parts of the Aleutian megathrust, respectively, based on satellite geodesy onshore. Both bays, located 200-km apart, face the Aleutian trench and harbor coastal evidence for tsunami inundation in 1957. Here we desc
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Alaska Science Center, Pacific Coastal and Marine Science Center

Sedimentary evidence of prehistoric distant-source tsunamis in the Hawaiian Islands

Over the past 200 years of written records, the Hawaiian Islands have experienced tens of tsunamis generated by earthquakes in the subduction zones of the Pacific "Ring of Fire" (e.g., Alaska-Aleutian, Kuril-Kamchatka, Chile, and Japan). Mapping and dating anomalous beds of sand and silt deposited by tsunamis in low-lying areas along Pacific coasts, even those distant from subduction zones, is cr
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Geologic Hazards Science Center, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory, Sediment Lab Suite and Carbon Analysis Laboratory

Investigation of input reduction techniques for morphodynamic modeling of complex inlets with baroclinic forcing

The Mouth of the Columbia River (MCR) is a complex estuary inlet system characterized by a buoyant plume created by high freshwater flows from the Columbia River into the Pacific Ocean. Data obtained during two major field campaigns have resulted in a comprehensive dataset of hydrodynamics and sediment transport under high (2013) and low (2005) river flow conditions. Through the analysis of this d
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Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Increased sediment load during a large-scale dam removal changes nearshore subtidal communities

The coastal marine ecosystem near the Elwha River was altered by a massive sediment influx—over 10 million tonnes—during the staged three-year removal of two hydropower dams. We used time series of bathymetry, substrate grain size, remotely sensed turbidity, scuba dive surveys, and towed video observations collected before and during dam removal to assess responses of the nearshore subtidal commun
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Ecosystems, Natural Hazards, Coastal and Marine Hazards and Resources Program, Fisheries Program (unpublished), Pacific Coastal and Marine Science Center, Western Fisheries Research Center

Coastal habitat and biological community response to dam removal on the Elwha River

Habitat diversity and heterogeneity play a fundamental role in structuring ecological communities. Dam emplacement and removal can fundamentally alter habitat characteristics, which in turn can affect associated biological communities. Beginning in the early 1900s, the Elwha and Glines Canyon dams in Washington, USA, withheld an estimated 30 million tonnes of sediment from river, coastal, and near
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Ecosystems, Coastal and Marine Hazards and Resources Program, Species Management Research Program, Pacific Coastal and Marine Science Center, Western Fisheries Research Center

Non-USGS Publications**

George, D.A., Gelfenbaum, G., and Stevens, A.W., 2012, Modeling the Hydrodynamic and Morphologic Response of an Estuary Restoration: Estuaries and Coasts, v. 35 no. 6, pp. 1510–1529, doi: 10.1007/s12237-012-9541-8.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

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Federal scientists from three agencies meet to discuss critical marine minerals

On July 30 and 31, the USGS Pacific Coastal and Marine Science Center hosted an “Exploratory Interagency Critical Marine Minerals Discussion” in Santa...

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USGS participates in Puget Sound Day on the Hill

Pacific Coastal and Marine Science Center director Guy Gelfenbaum and NW Region Staff Scientist Bill Labiosa represented the USGS in the Puget Sound...

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City of Santa Cruz staff briefed on USGS science activities

On October 17, 2018, 17 staff members from the City of Santa Cruz, California toured USGS facilities in the city.

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Congressman Jimmy Panetta visits USGS Pacific Coastal and Marine Science Center

On September 18, 2018, Congressman Jimmy Panetta (20th district, California) and staffer Emmanuel Garcia visited the USGS Pacific Coastal and Marine...

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Gelfenbaum Selected as New Director of USGS Pacific Marine Studies

The U.S. Geological Survey is pleased to announce the selection of Dr. Guy Gelfenbaum as the new director of their Pacific Coastal and Marine Science...

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