Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSB scientists compile first study of potential for tsunamis in northwestern California

28.06.2012
Using studies that span the last three decades, scientists at UC Santa Barbara have compiled the first evidence-based comprehensive study of the potential for tsunamis in Northwestern California.

The paper, "Paleoseismicity of the Southern End of the Cascadia Subduction Zone, Northwestern California," was co-written by professors Edward Keller and Alexander Simms from UCSB's Department of Earth Science, and published in a recent issue of the Bulletin of the Seismological Society of America.

The paper is based on the Ph.D. dissertation of David Valentine, a research programmer at the Spatial Information Systems Laboratory at UC San Diego. Valentine, Keller's former student, completed his doctorate at UCSB in 2002 and is first author of the paper.

The region has long been known to experience large earthquakes, and scientific studies of seismic activity in the southern end of the Cascadia Subduction Zone (CSZ) –– which stretches northward from the area of Mendocino, Calif. –– have previously appeared in grey literature and in guidebooks. However, comprehensive, reviewed evidence-based work has been lacking, according to Keller.

"Science goes on evidence," he said, adding that in light of the recent earthquakes in Japan and Chile, the study of the same potential closer to home is "timely." The authors studied sedimentation patterns in salt marshes, floodplains, and estuaries in the northwestern corner of California for signs of seismic events that could lead to tsunami activity. They combined this with information gathered from numerous studies conducted over nearly 30 years by researchers at Humboldt State University

During an earthquake, the researchers say, there is a tendency for the coastal wetlands to become submerged, with coastal sediments depositing over plants and animals that live there. These become a fossilized record of sea-level change in the area.

The process has preserved a sequence of marsh surfaces and forest soils. Analysis of structure, texture, and organic content, as well as the use of radiocarbon dating to identify the age of the materials, revealed evidence of smaller strong-to-major earthquakes in the area (magnitude 6.5 to 7.2). Larger quakes (greater than magnitude 8.2) that involved the regional subduction zone, were also in evidence.

According to the study, the local California section has experienced three major earthquakes over the last 2000 years, and accompanying local sea-level changes at roughly 300- to 400-year intervals, with the last one occurring 500 to 600 years ago. The researchers also found that the entire CSZ erupted, causing local submergence at least three times in roughly 500- to 600- year intervals, the last activity taking place in 1700 AD.

"It's not a matter of if, but when," said Keller, of the potential for the next major earthquake/tsunami event in the region –– a great earthquake that would impact not only the Northwest, but also send waves to Japan and Hawaii. The evidence, he said, is leading to far more foresight and planning along the impact areas in the region to avoid catastrophes on a level with the Japan earthquake of 2011 or the Indian Ocean quake of 2004.

Other researchers contributing to the study include Gary Carver, a professor emeritus at Humboldt State University; Wen Hao Li from Northrup Grummond Co. in Redondo Beach; and Christine Manhart from Environmental Services and Consulting in Blacksburg, Va.

Sonia Fernandez | EurekAlert!
Further information:
http://www.ucsb.edu

Further reports about: CSZ California Science TV Subduction UCSB Zone sea-level change

More articles from Earth Sciences:

nachricht Mountain glaciers shrinking across the West
23.10.2017 | University of Washington

nachricht Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>