Getting a better understanding of how the 2009-10 conditions tore away and reshaped shorelines will help coastal experts better predict future changes that may be in store for the Pacific coast, the researchers say.
"The stormy conditions of the 2009-10 El Nino winter eroded the beaches to often unprecedented levels at sites throughout California and vulnerable sites in the Pacific Northwest," said Patrick Barnard, a coastal geologist with the United States Geological Survey in Santa Cruz, Calif. In California, for example, winter wave energy was 20 percent above average for the years dating back to 1997, resulting in shoreline erosion that exceeded the average by 36 percent, he and his colleagues found.
Barnard's team published their results last Saturday, 9 July, in Geophysical Research Letters, a journal of the American Geophysical Union.
Among the most severe erosion was at Ocean Beach in San Francisco where the winter shoreline retreated 56 meters (184 feet), 75 percent more than the typical winter. The erosion resulted in the collapse of one lane of a major roadway and led to a 5 million dollar emergency remediation project. In the Pacific Northwest, the regional impacts were moderate, but the southerly shift in storm tracks, typical of El Nino winters, resulted in severe local wave impacts to the north-of- harbor mouths and tidal inlets. For example, north of the entrance to Willapa Bay along the Washington coast, 105 m (345 ft) of shoreline erosion during 2009-10 destroyed a road.
The beach erosion observed throughout the U.S. West Coast during the 2009-10 El Nino is linked to the El Nino Modoki ('pseudo' El Nino) phenomenon, where the warmer sea surface temperature is focused in the central equatorial Pacific (as opposed to the eastern Pacific during a classic El Nino). As a result of these conditions, the winter of 2009-10 was characterized by above average wave energy and ocean water levels along much of the West Coast, conditions not seen since the previous major El Nino (classic) in 1997-98, which contributed to the observed patterns of beach and inlet erosion.
As even warmer waters in the central Pacific are expected in the coming decades under many climate change scenarios, El Nino Modoki is projected to become a more dominant climate signal. When combined with still higher sea levels expected due to global warming, and potentially even stronger winter storms, these factors are likely to contribute to increased rates of beach and bluff erosion along much of the U.S. West Coast, producing regional, large-scale coastal changes.
(148 miles) of coastline and tracked shoreline changes through a range of wave conditions.Title:
Jonathan Allan: Coastal Field Office, Oregon Department of Geology and Mineral Industries, Newport, Oregon, USA;
Jeff E. Hansen: Pacific Coastal and Marine Science Center, U.S. Geological Survey, Santa Cruz, California, USA; and Department of Earth and Planetary Sciences, University of California, Santa Cruz, California, USA;
George M. Kaminsky: Coastal Monitoring and Analysis Program, Washington State Department of Ecology, Olympia, Washington, USA;
Peter Ruggiero: Department of Geosciences, Oregon State University, Corvallis, Oregon, USA;
Andre Doria: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA.Author contact:
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences