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Data are time series of substrate grain size, remotely sensed water column turbidity, and measures of abundance (e.g., density, percent cover) of the nearshore subtidal (3-17 m depth) benthic community (vegetation, invertebrates, and fish) collected before (2008-2011) and during dam removal (2012-2014).
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In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~ 140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including...
Categories: Publication; Types: Citation; Tags: Quaternary Research
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This portion of the USGS data release presents bathymetry data collected during surveys performed on the Elwha River delta, Washington in July 2015 (USGS Field Activity Number 2015-648-FA). Bathymetry data were collected using two personal watercraft (PWCs), each equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The PWC sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9° beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a YSI CastAway CTD during the survey....
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This portion of the USGS data release presents topography data collected during surveys performed on the Elwha River delta, Washington, in May 2011 (USGS Field Activity Number W-04-11-PS). Topography data were collected on foot with global navigation satellite system (GNSS) equipment mounted on backpacks operating in Real-Time Kinematic (RTK) mode. A total of 3 GNSS backpacks, each equipped with a dual-frequency GNSS receiver and handheld data collector, were used during the survey. Differential corrections were transmitted at 1-Hz intervals by a VHF radio to the backpack GNSS receivers from a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum...
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This portion of the USGS data release presents bathymetry data collected during surveys performed on the Elwha River delta, Washington in September 2010 (USGS Field Activity Number W-03-10-PS). Bathymetry data were collected using a small boat and a personal watercraft (PWC), each equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The sonar systems on the survey vessels consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9° beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a...
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Studies of terrestrial biotic and environmental dynamics of the last interglacial period, Marine Oxygen Isotope Stage (MIS) 5, provide insight into the effects of long-term climate change on Pleistocene ecosystems. In North America, however, there are relatively few fossil sites that definitively date to MIS 5. Even fewer contain multiple ecosystem components (vertebrates, invertebrates, plants) that have been studied in detail, and none are located at high elevation. Thus, our view of North American ecosystems during MIS 5 is, at best, an incomplete composite view, and alpine ecosystems are entirely undocumented. The Ziegler Reservoir fossil site allows us to begin filling these gaps. Discovered on October 14,...
Categories: Publication; Types: Citation; Tags: Quaternary Research
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Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of mud, sand, and gravel since 1927, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams, initiated in September 2011, induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the geomorphic response of a coastal delta to these increases. Detailed measurements of beach topography and nearshore bathymetry show that ~ 2.5 million m3 of sediment was deposited during the first two years of dam removal, which is ~ 100 times greater than deposition rates measured prior to dam removal. The majority of the deposit...
Categories: Publication; Types: Citation; Tags: Geomorphology
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This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted on the Elwha River delta in February 2016 (USGS Field Activity Number 2016-608-FA). Nearshore bathymetry data were collected using two personal watercraft (PWCs) and a kayak equipped with single-beam echosounders and survey-grade global navigation satellite systems (GNSS) receivers. Topographic data were collected on foot with survey-grade GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization)...
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This portion of the USGS data release presents sediment grain-size data from on the Elwha River delta, Washington in July and August, 2015 (USGS Field Activities 2015-648-FA and 2015-652-FA). Bed sediment was sampled using a small ponar, or 'grab', sampler on July 28, 2016 from the R/V Frontier at a total of 70 locations in water depths between approximately 1 and 17 m around the delta. An additional 17 samples were obtained by SCUBA divers between July 22 and August 23, 2015 using a 15 cm diameter push corer inserted into the seabed as far as possible to a maximum depth of 15 cm. Forty-eight samples were collected at low tide at intertidal locations on the delta. The locations of grab samples and intertidal samples...
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This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted on the Elwha River delta in July 2018 (USGS Field Activity Number 2018-648-FA). Nearshore bathymetry data were collected using two personal watercraft (PWCs) and a kayak equipped with single-beam echosounders and survey-grade global navigation satellite systems (GNSS) receivers. Topographic data were collected on foot with survey-grade GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization)...
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The removal of two dams on the Elwha River will introduce massive volumes of sediment to the river, and this increase in sediment supply in the river will likely modify the shapes and forms of the river and coastal landscape downstream of the dams. This chapter provides the geologic and geomorphologic background of the Olympic Peninsula and the Elwha River with emphasis on the present river and shoreline. The Elwha River watershed was formed through the uplift of the Olympic Mountains, erosion and movement of sediment throughout the watershed from glaciers, and downslope movement of sediment from gravitational and hydrologic forces. Recent alterations to the river morphology and sediment movement through the river...
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This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted on the Elwha River delta, Washington, in April 2014 (USGS Field Activity Number 2014-620-FA). Nearshore bathymetry data were collected using two personal watercraft (PWCs) equipped with single-beam echosounders and survey-grade global navigation satellite system (GNSS) receivers. Topography data were collected on foot with survey-grade GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization)...
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This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted on the Elwha River delta, Washington, in March 2013 (USGS Field Activity Number W-01-13-PS). Nearshore bathymetry data were collected using two personal watercraft (PWCs) equipped with single-beam echosounders and survey-grade global navigation satellite system (GNSS) receivers. Topography data were collected on foot with survey-grade GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization) and...
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This portion of the USGS data release presents bathymetric data collected during surveys performed on the Elwha River delta, Washington in 2018 (USGS Field Activity Number 2018-648-FA). Bathymetric data were collected using personal watercraft (PWCs) equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers.
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Models quantifying the onset of sediment motion do not typically account for the effect of biotic processes because they are difficult to isolate and quantify in relation to physical processes. Here we investigate an example of the interaction of kelp (Order Laminariales) and coarse sediment transport in the coastal zone, where it is possible to directly quantify and test its effect. Kelp is ubiquitous along rocky coastlines and the impact on ecosystems has been well studied. We develop a physical model to explore the reduction in critical shear stress of large cobbles colonized by Nereocystis luetkeana, or bull kelp. Observations of coarse sediment motion at a site in the Strait of Juan de Fuca (northwest United...
Categories: Publication; Types: Citation; Tags: Geology
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The geologic setting of the Ziegler Reservoir fossil site is somewhat unusual – the sediments containing the Pleistocene fossils were deposited in a lake on top of a ridge. The lake basin was formed near the Town of Snowmass Village, Colorado when a glacier flowing down Snowmass Creek Valley became thick enough to overtop a low point in the eastern valley wall and entered the head of Brush Creek Valley. When the glacier retreated at the end of the marine isotope stage (MIS) 6, ~155-130 ka (thousands of years before present), the Brush Creek Valley lobe left behind a moraine that impounded a small alpine lake. The lake was initially ~10 m deep and was highly productive during most of its existence based on the abundant...
Categories: Publication; Types: Citation; Tags: Quaternary Research
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To understand the effects of increased sediment supply from dam removal on marine habitats around the Elwha River delta, a basic understanding of the region’s coastal processes is necessary. This chapter provides a summary of the physical setting of the coast near the Elwha River delta, for the purpose of synthesizing the processes that move and disperse sediment discharged by the river. One fundamental property of this coastal setting is the difference between currents in the surfzone with those in the coastal waters offshore of the surfzone. Surfzone currents are largely dictated by the direction and size of waves, and the waves that attack the Elwha River delta predominantly come from Pacific Ocean swell from...
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This portion of the USGS data release presents sediment grain-size data from samples on the Elwha River delta, Washington, in February 2016 (USGS Field Activity Number 2016-608-FA). Surface sediment was collected at a total of 83 locations using a small ponar, or 'grab', sampler from the R/V Frontier in water depths between 1 and 17 m around the delta. An additional 18 samples were collected by hand at low tide. A handheld global satellite navigation system (GNSS) receiver was used to determine the locations of sediment samples. Grab samples that yielded less than 50 g of sediment were omitted from analysis and are classified as "no sample". The grain-size distributions of samples that yielded more than 50 g of...
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This portion of the USGS data release presents sediment grain-size data from samples collected on the Elwha River delta, Washington, in September 2013 (USGS Field Activity Number W-07-13-PS). Surface sediment was sampled using a small ponar, or 'grab', sampler on September 19, 2013 from the R/V Frontier at a total of 62 locations in water depths between about 1 and 12 m around the delta. An additional 21 sediment samples were collected between September 16 and September 19, 2013 at low tide from intertidal locations on the delta. A handheld GNSS receiver was used to determine the locations of sediment samples. The grain-size distributions of samples were determined in the USGS Pacific Coastal and Marine Science...


map background search result map search result map Coastal processes of the Elwha River delta: Chapter 5 in <i>Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal</i> Geomorphology of the Elwha River and its Delta: Chapter 3 in <i>Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal</i> Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado Digital elevation models (DEMs) of the Elwha River delta, Washington, February 2016 Surface-sediment grain-size distributions from the Elwha River delta, Washington, February 2016 Nearshore bathymetry data from the Elwha River delta, Washington, July 2015 Surface-sediment grain-size distributions from the Elwha River delta, Washington, July 2015 Digital elevation models (DEMs) of the Elwha River delta, Washington, April 2014 Surface-sediment grain-size distributions from the Elwha River delta, Washington, September 2013 Digital elevation models (DEMs) of the Elwha River delta, Washington, March 2013 Topography data from the Elwha River delta, Washington, May 2011 Nearshore bathymetry data from the Elwha River delta, Washington, September 2010 Data collected in 2008-2014 to assess nearshore subtidal community responses to increased sediment load during removal of the Elwha River dams, Washington State, USA Nearshore bathymetry data from the Elwha River delta, Washington, July 2018, collected from personal watercraft Digital elevation models (DEMs) of the Elwha River delta, Washington, July 2018 Topography data from the Elwha River delta, Washington, May 2011 Surface-sediment grain-size distributions from the Elwha River delta, Washington, July 2015 Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado Geomorphology of the Elwha River and its Delta: Chapter 3 in <i>Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal</i> Data collected in 2008-2014 to assess nearshore subtidal community responses to increased sediment load during removal of the Elwha River dams, Washington State, USA Coastal processes of the Elwha River delta: Chapter 5 in <i>Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal</i>