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:
Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter
17.08.2017 | Swansea University
Climate change: In their old age, trees still accumulate large quantities of carbon
17.08.2017 | Universität Hamburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences