Navigation Links
Alpine Fault study shows new evidence for regular magnitude 8 earthquakes
Date:7/25/2012

RENO, Nev. A new study published in the prestigious journal Science, co-authored by University of Nevada, Reno's Glenn Biasi and colleagues at GNS Science in New Zealand, finds that very large earthquakes have been occurring relatively regularly on the Alpine Fault along the southwest coastline of New Zealand for at least 8,000 years.

The Alpine Fault is the most hazardous fault on the South Island of New Zealand, and about 80 miles northwest of the South Island's main city of Christchurch.

The team developed evidence for 22 earthquakes at the Hokuri Creek site, which, with two additional from nearby, led to the longest continuous earthquake record in the world for a major plate boundary fault. The team established that the Alpine Fault causes, on average, earthquakes of around a magnitude 8 every 330 years. Previous data put the intervals at about 485 years.

Relative motion of Australian and Pacific plates across the Alpine Fault averages almost an inch per year. This motion builds up, and then is released suddenly in large earthquakes. The 530-mile-long fault is among the longest, straightest and fastest moving plate boundary faults in the world. More than 23 feet of potential slip has accumulated in the 295 years since the most recent event in A.D. 1717.

Biasi, working with the GNS Science team led by Kelvin Berryman, used paleoseismology to extend the known seismic record from 1000 years ago to 8,000 years ago. They estimated earthquake dates by combining radiocarbon dating leaves, small twigs and marsh plants with geologic and other field techniques.

"Our study sheds new light on the frequency and size of earthquakes on the Alpine Fault. Earthquakes have been relatively periodic, suggesting that this may be a more general property of simple plate boundary faults worldwide," Biasi, of the Nevada Seismological Laboratory said. "By comparison, large earthquakes on California's San Andreas Fault have been less regular in size and timing."

"Knowing the average rate of earthquakes is useful, but is only part of the seismic hazard equation," he said. "If they are random in time, then the hazard does not depend on how long it has been since the most recent event. Alpine Fault earthquakes are more regular in their timing, allowing us to use the time since the last earthquake to adjust the hazard estimate. We estimate the 50-year probability of a large Alpine fault earthquake to be about 27 percent."

A magnitude 7.1 earthquake centered near Christchurch, the largest city in the South Island of New Zealand, caused extensive damage to buildings on Sept. 2, 2010, and no deaths. On Feb. 22, 2011, a triggered aftershock measuring magnitude 6.3, with one of the strongest ground motions ever recorded worldwide in an urban area, struck the city killing 185 people.


'/>"/>

Contact: Mike Wolterbeek
mwolterbeek@unr.edu
University of Nevada, Reno
Source:Eurekalert  

Related biology news :

1. Friendly to a fault, yet tense: Personality traits traced in brain
2. Johns Hopkins researchers uncover genes at fault for cystic fibrosis-related intestinal obstruction
3. Understanding faults and volcanics, plus life inside a rock
4. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
5. Law that regulates shark fishery is too liberal: UBC study
6. New study will help protect vulnerable birds from impacts of climate change
7. Study jointly led by UCSB researcher supports theory of extraterrestrial impact
8. BYU study: Using a gun in bear encounters doesnt make you safer
9. 15-year study: When it comes to creating wetlands, Mother Nature is in charge
10. Pycnogenol (French maritime pine bark extract) shown to improve menopause symptoms in new study
11. Crystal structure of archael chromatin clarified in new study
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Alpine Fault study shows new evidence for regular magnitude 8 earthquakes
(Date:5/16/2017)...  Veratad Technologies, LLC ( www.veratad.com ), an innovative ... verification solutions, announced today they will participate as a ... thru May 17, 2017, in Washington D.C.,s ... Identity impacts the lives of billions ... evolving digital world, defining identity is critical to nearly ...
(Date:4/18/2017)... a global expert in SoC-based imaging and computing solutions, has developed ... the company,s hybrid codec technology. A demonstration utilizing TeraFaces ® , ... showcased during the upcoming Medtec Japan at Tokyo Big Sight April ... Vegas Convention Center April 24-27. ... Click here for an image of the M820 ...
(Date:4/11/2017)... Research and Markets has announced the addition of the "Global ... ... at a CAGR of 30.37% during the period 2017-2021. ... based on an in-depth market analysis with inputs from industry experts. ... the coming years. The report also includes a discussion of the ...
Breaking Biology News(10 mins):
(Date:8/11/2017)... ... 11, 2017 , ... “There is an increasing consumer call ... synthetic ingredients,” said Matt Hundt, President of Third Wave Bioactives. “Combining the strong ... know-how of Biorigin will allow us to bring truly novel fermented ingredient technologies ...
(Date:8/10/2017)... ... August 09, 2017 , ... ... applications in the clinic is here. The team at Capricor Therapeutics, Inc. utilized ... medium for clinical studies. , Dr. Travis Antes, head of analytical development ...
(Date:8/10/2017)... USA (PRWEB) , ... August 09, 2017 , ... ... partnered with four international biomedical optics laboratories — the Wellman Center for Photomedicine, ... Medical Laser Center Lübeck and the Beckman Laser Institute at University of California, ...
(Date:8/10/2017)... ... August 10, 2017 , ... CNA Finance Chief Research Analyst, ... on Next Group Holdings, Inc. and see's significant opportunity in the company's plans ... cannot engage in traditional banking services. According to industry estimates, approximately 103 million ...
Breaking Biology Technology: