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George M. Kaminsky

Publications and source records attributed to George M. Kaminsky.

12 recordsLinked to original sources
USGS2026

ENSO and PDO drive shoreline position anomalies in the U.S. Pacific Northwest

Sandy beaches act as buffers against various coastal hazards but are vulnerable to episodic (seasonal) and chronic (interannual) erosion. Understanding the variation of shoreline position, a key metric in coastal morphology, over a spectrum of time scales is therefore crucial in assessing hazard vulnerability. Long-standing research has investigated the role of El Niño-Southern Oscillation (ENSO), the dominant mode of climate variability in the Pacific Basin, in seasonal shoreline variability. Yet, ENSO’s chronic influence—and that of another Pacific climate mode, the Pacific Decadal Oscillation (PDO)—on shoreline anomalies remains poorly understood. Here, we examine the variability of sandy beaches in the US Pacific Northwest, a ∼750 km long coastal region on the US West Coast. We leverage 40 years (1984–2024) of shoreline data from publicly available Earth-observing (Landsat) satellite imagery at a high spatial resolution (>10,000 shore-normal transects at 50-m alongshore spacing) and employ Convergent Cross Mapping (CCM), a methodology for inferring causality in dynamical systems. We discover that strong El Niño years are signified by erosion (75.1% of transects), and strong La Niña years exhibit accretional behavior (73.4% of transects). Furthermore, we establish, for the first time, that both ENSO and PDO exert a statistically significant control on interannual shoreline variability, particularly on the alongshore component (in 95 and 100% of littoral cells, respectively), with water level fluctuations playing a critical role. This effort advances our understanding of the seasonal-to-interannual interactions between Pacific Basin climate variability and the PNW’s coastal morphodynamics, with implications for sediment management and coastal adaptation.

California, Oregon, Washington↗
USGS2020

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 Beach, Wash., a 3-km-long stretch of coastline immediately north of the Columbia River inlet. Despite the placement of approximately 6.3 million cubic meters (Mm 3 ) of sand dredged from the Columbia River navigational channel at nearshore placement sites located nearby, Benson Beach eroded 2.1±0.8 Mm 3 over the 5-year (yr) monitoring time period (420,000 cubic meters/year [m 3 /yr]). A hydrodynamic and sediment transport model was applied to simulate sediment transport fluxes, and a new visualization technique was developed to evaluate the linkages between nearshore dredge placement sites and adjacent coastlines near the mouth of the Columbia River. The model results indicate the dominance of wave processes on sediment-transport patterns outside of the inlet and suggest that the current configuration of the nearshore dredge placement sites can be improved to more efficiently enhance the sediment budget of Benson Beach to reduce erosion and mitigate associated coastal change hazards.

Oregon, Washinton↗
USGS2017

Extreme oceanographic forcing and coastal response due to the 2015–2016 El Niño

The El Niño-Southern Oscillation is the dominant mode of interannual climate variability across the Pacific Ocean basin, with influence on the global climate. The two end members of the cycle, El Niño and La Niña, force anomalous oceanographic conditions and coastal response along the Pacific margin, exposing many heavily populated regions to increased coastal flooding and erosion hazards. However, a quantitative record of coastal impacts is spatially limited and temporally restricted to only the most recent events. Here we report on the oceanographic forcing and coastal response of the 2015–2016 El Niño, one of the strongest of the last 145 years. We show that winter wave energy equalled or exceeded measured historical maxima across the US West Coast, corresponding to anomalously large beach erosion across the region. Shorelines in many areas retreated beyond previously measured landward extremes, particularly along the sediment-starved California coast.

Pacific coast↗
USGS2015

Coastal change from a massive sediment input: Dam removal, Elwha River, Washington, USA

The removal of two large dams on the Elwha River, Washington, provides an ideal opportunity to study coastal morphodynamics during increased sediment supply. The dam removal project exposed ~21 million cubic meters (~30 million tonnes) of sediment in the former reservoirs, and this sediment was allowed to erode by natural river processes. Elevated rates of sand and gravel sediment transport in the river occurred during dam removal. Most of the sediment was transported to the coast, and this renewed sediment supply resulted in hundreds of meters of seaward expansion of the river delta since 2011. Our most recent survey in January 2015 revealed that a cumulative ~3.5 million m 3 of sediment deposition occurred at the delta since the beginning of the dam removal project, and that aggradation had exceeded 8 m near the river mouth. Some of the newly deposited sediment has been shaped by waves and currents into a series of subaerial berms that appear to move shoreward with time.

Washington↗
USGS2012

Southwest Washington littoral drift restoration—Beach and nearshore morphological monitoring

A morphological monitoring program has documented the placement and initial dispersal of beach nourishment material (280,000 m3) placed between the Mouth of the Columbia River (MCR) North Jetty and North Head, at the southern end of the Long Beach Peninsula in southwestern Washington State. A total of 21 topographic surveys and 8 nearshore bathymetric surveys were performed between July 11, 2010, and November 4, 2011. During placement, southerly alongshore transport resulted in movement of nourishment material to the south towards the MCR North Jetty. Moderate wave conditions (significant wave height around 4 m) following the completion of the nourishment resulted in cross-shore sediment transport, with most of the nourishment material transported into the nearshore bars. The nourishment acted as a buffer to the more severe erosion, including dune overtopping and retreat, that was observed at the northern end of the study area throughout the winter. One year after placement of the nourishment, onshore transport and beach recovery were most pronounced within the permit area and to the south toward the MCR North Jetty. This suggests that there is some long-term benefit of the nourishment for reducing erosion rates locally, although the enhanced recovery also could be due to natural gradients in alongshore transport causing net movement of the sediment from north to south. Measurements made during the morphological monitoring program documented the seasonal movement and decay of nearshore sand bars. Low-energy conditions in late summer resulted in onshore bar migration early in the monitoring program. Moderate wave conditions in the autumn resulted in offshore movement of the middle bar and continued onshore migration of the outer bar. High-energy wave conditions early in the winter resulted in strong cross-shore transport and creation of a 3-bar system along portions of the coast. More southerly wave events occurred later in the winter and early spring and coincided with the complete loss of the outer bar and net loss of sediment from the study area. These data suggest that bar decay may be an important mechanism for exporting sediment from Benson Beach north to the Long Beach Peninsula. The measurements presented in this report represent one component of a broader monitoring program designed to track the movement of nourishment material on the beach and shoreface at this location, including continuous video monitoring (Argus), in situu measurements of hydrodynamics, and a physical tracer experiment. Field data from the monitoring program will be used to test numerical models of hydrodynamics and sediment transport and to improve the capability of numerical models to support regional sediment management.

Washington↗
USGS2011

The impact of the 2009-10 El Niño Modoki on U.S. West Coast beaches

High-resolution beach morphology data collected along much of the U.S. West Coast are synthesized to evaluate the coastal impacts of the 2009–10 El Niño. Coastal change observations were collected as part of five beach monitoring programs that span between 5 and 13 years in duration. In California, regional wave and water level data show that the environmental forcing during the 2009–10 winter was similar to the last significant El Niño of 1997–98, producing the largest seasonal shoreline retreat and/or most landward shoreline position since monitoring began. In contrast, the 2009–10 El Niño did not produce anomalously high mean winter-wave energy in the Pacific Northwest (Oregon and Washington), although the highest 5% of the winter wave-energy measurements were comparable to 1997–98 and two significant non-El Niño winters. The increase in extreme waves in the 2009–10 winter was coupled with elevated water levels and a more southerly wave approach than the long-term mean, resulting in greater shoreline retreat than during 1997–98, including anomalously high shoreline retreat immediately north of jetties, tidal inlets, and rocky headlands. The morphodynamic response observed throughout the U.S. West Coast during the 2009–10 El Niño is principally linked to the El Niño Modoki phenomena, where the warm sea surface temperature (SST) anomaly is focused in the central equatorial Pacific (as opposed to the eastern Pacific during a classic El Niño), featuring a more temporally persistent SST anomaly that results in longer periods of elevated wave energy but lower coastal water levels.

Geophysical Research Letters↗
USGS2010

Large-scale coastal change in the Columbia River littoral cell: an overview

This overview introduces large-scale coastal change in the Columbia River littoral cell (CRLC). Covering 165 km of the southwest Washington and northwest Oregon coasts, the littoral cell is made up of wide low-sloping dissipative beaches, broad coastal dunes and barrier plains, three large estuaries, and is bounded by rocky headlands. The beaches and inner shelf are composed of fine-grained sand from the Columbia River and are exposed to a high-energy winter wave climate. Throughout the Holocene, the CRLC has undergone large fluctuations in shoreline change trends, responding to a variety of coastal change drivers, including changing rates of sea-level rise, infrequent, yet catastrophic, co-seismic subsidence events, a large regional sediment supply, inter-annual climatic fluctuations (El Niño cycles), seasonally varying wave climate, and numerous anthropogenic influences. Human influences on the CRLC include construction of over 200 dams in the Columbia River drainage basin, dredging of navigation channels removing sand to upland sites and offshore deep-water sites, and construction of large inlet jetties at the entrances to the Columbia River and Grays Harbor. The construction of these massive entrance jetties at the end of the 19th century has been the dominant driver of coastal change through most of the littoral cell over the last hundred years. Presently, some beaches in the littoral cell are eroding in response to nearshore sediment deficits resulting from a) ebb-jets of the confined entrances pushing the previously large, shallow ebb-tidal deltas offshore into deeper water, and b) waves dispersing the nearshore delta flanks initially onshore and then alongshore away from the jetties. This overview describes 1) the motivation for developing a system-wide understanding of sediment dynamics in the littoral cell at multiple time and space scales, 2) the formation and approach of the Southwest Washington Coastal Erosion Study, and 3) an introduction to the papers in this special issue.

Washington;Oregon↗
USGS2010

Modeling the effects of wave climate and sediment supply variability on large-scale shoreline change

The application of an integrated data analysis and modeling scheme reveals that decadal-scale shoreline evolution along a U.S. Pacific Northwest littoral cell is highly dependent on both sediment supply and wave climate variability. In particular, accurate estimates of (Columbia River) sediment supply and sediment feeding from the lower shoreface are critical components of balancing the barrier beach sediment budget and are therefore essential to making sensible shoreline change hindcasts and forecasts. A simple deterministic one-line shoreline change model, applied in a quasi-probabilistic manner, enables evaluation of the influence of sediment supply and wave climate variability through simulation of historical shoreline change. Through iteration, a range of realistic scenarios are developed to constrain decadal-scale shoreline change predictions. Modeled shoreline changes are significantly sensitive to directional changes in the incident waves, and therefore sensitive to the occurrence of interannual climatic fluctuations such as major El Niño events. A predicted increase in the intensity of the east Pacific wave climate (1.0 m increase in significant wave height in 20 yr) affects forecast shoreline positions only when this increase occurs during the winter storm season. However, the effect of this increase in storm power during any given year is small relative to the impact of major El Niño events. The model has significant skill in decadal-scale hindcasts suggesting that alongshore gradients in sediment transport dominate coastal change at this scale at this site. However, both data and model results suggest that net onshore feeding from the lower shoreface is responsible for approximately 20% of the decadal-scale coastal change. Field measurements and poor model skill at annual scale indicate that cross-shore processes likely dominate coastal change at shorter time scales.

Oregon, Washington↗
USGS2007

Beach morphology monitoring in the Columbia River Littoral Cell: 1997-2005

This report describes methods used, data collected, and results of the Beach Morphology Monitoring Program in the Columbia River Littoral Cell (CRLC) from 1997 to 2005. A collaborative group primarily consisting of the US Geological Survey and the Washington State Department of Ecology performed this work. Beach Monitoring efforts consisted of collecting topographic and bathymetric horizontal and vertical position data using a Real Time Kinematic Differential Global Positioning System (RTK-DGPS). Sediment size distribution data was also collected as part of this effort. The monitoring program was designed to: 1) quantify the short- to medium-term (seasonal to interannual) beach change rates and morphological variability along the CRLC and assess the processes responsible for these changes; 2) collect beach state data (i.e., grain size, beach slope, and dune/sandbar height/position) to enhance the conceptual understanding of CRLC functioning and refine predictions of future coastal change and hazards; 3) compare and contrast the scales of environmental forcing and beach morphodynamics in the CRLC to other coastlines of the world; and 4) provide beach change data in a useful format to land use managers.

Oregon, Washington↗
USGS2007

Beach morphology monitoring in the Elwha River Littoral Cell, 2004-2009

This report describes the methods used, data collected, and results of the Beach Morphology Monitoring Program in the Elwha River Littoral Cell, starting in 2004. The U.S. Geological Survey and the Washington State Department of Ecology collaborated in the data collection with the support of the local Lower Elwha Klallam Tribe. Beach monitoring efforts consisted of collecting topographic and bathymetric horizontal and vertical position data by using a Real Time Kinematic Differential Global Positioning System (RTK-DGPS). The monitoring program was designed to characterize the littoral system of the Elwha River before the scheduled removal of two large dams in 2012. A primary objective of this work is to quantitatively describe the topography and bathymetry of the Elwha River littoral system so that the effects of dam removal may be quantified. Sediment inputs following dam removal are hypothesized to result in (A) larger amounts of fine sediment grain-sizes entering the littoral system and, (B) a reduction or reversal of coastal erosion.

Washington↗