Now isn't that just special.....
For links see article source.....
Posted for fair use.....
http://www.mercurynews.com/2016/10/20/2-bay-area-earthquake-faults-found-to-be-connected/
The Mercury News
Two Bay Area earthquake faults found to be connected
A sign notifying people they are standing on the Hayward Fault stands at the children’s area at the Oakland Zoo in Oakland. New research published in the journal Science Advances on Wednesday found that the Hayward Fault may be linked to another fault. (File Photo)
By Patrick May | pmay@bayareanewsgroup.com
PUBLISHED: October 20, 2016 at 6:40 am | UPDATED: October 20, 2016 at 1:48 pm
*
Just in time for today’s Great California ShakeOut earthquake drills comes a newly published*study with a troubling finding:
Two of the Bay Area’s most infamous and potentially deadly earthquake faults may be linked, potentially packing a greater punch than even the 1989 Loma Prieta temblor.
The pair-up is troubling: once thought to be two miles apart under the bay, the Rodgers Creek Fault, running from near Santa Rosa into the San Pablo Bay, and the Hayward Fault, stretching from below San Jose through the Oakland and Berkeley hills into West Contra Costa County, may indeed form one 99-mile-long fault that could deliver a blow greater than the sum of its parts.
“This should be a reminder that folks in the Bay Area need to be prepared for a major earthquake,” said*Janet Watt,*research geophysicist with the U.S. Geological Survey in Santa Cruz, in an email this week to the AP. She’s one of the four authors of the study which appears this week in Science Advances.
This is not the first time these findings have been made public: In a story last January in this newspaper, Watt said “it does look like there is a good chance that the faults are connected.” But with the publication of her team’s findings, their research promises to resonate even more strongly among quake-wary residents of the San Francisco Bay Area.
Extent of the Hayward-Rodgers Creek fault zone shown in red. Black lines show other major faults. White box shows study area. Cities are marked with letters: AR, Alum Rock; H, Healdsburg; L, Livermore; O, Oakland; SF, San Francisco; SR, Santa Rosa.
The team’s underwater surveys revealed a previously unknown strand of the Hayward Fault that connects to the western section of the Rodgers Creek Fault. One reason why it has taken so long to determine the relationship between the two faults is because the bay is very shallow, which makes it hard to use a boat. Researchers floated instruments on pontoons.
Should the power of the two faults join forces, they are more likely to cause a magnitude-7.2 quake, about three times stronger than the magnitude-6.9 Loma Prieta quake, which in 1989 violently shook the Bay Area, killed 63 people and caused an estimated $6 billion in damage.
“The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults,” the authors wrote. “Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery.”
But now, the scientists say, sophisticated imaging tools looking beneath the Bay Area’s surface have unearthed a scary scenario:
“The Hayward and Rodgers Creek faults are directly connected at the surface—a geometric relationship that has significant implications for earthquake dynamics and seismic hazard,” says the article. “A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact.”
The findings were the result of work by Watt and her team in 2014 when they seismically mapped the earth under San Pablo Bay. Their search produced an image of a strand linking the two faults, she said. Until then the Rodgers Creek and Hayward faults had been thought to be independent but capable of influencing each other.
Related Articles
Earthquake alert issued for Southern California
Yet even as scientists fear the Hayward-Rodgers Creek fault zone could wallop the region with a powerful quake in the next 30 years, “the location and connectivity of the Hayward and Rodgers Creek faults remain uncertain beneath San Pablo Bay.”
*
The eastern span of the Bay Bridge after the Loma Prieta quake
So much of the earlier mystery remains, and the authors warn that “resolving this uncertainty is particularly important because the alternative fault models (fault stepover versus fault bend) have different implications for earthquake hazard.”And quake history is important, Watt said. “There hasn’t been a quake along the Hayward Fault since 1868.*There’s (geological) seismic evidence showing they may have ruptured together in 1700s or in two separate breaks within decades of each other.”
*
And for more information about today’s Great California ShakeOut, go here.
Credit: ScienceAdvances; U.S. Geological Survey
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Tags:*Earthquake
Patrick May Patrick May is an award-winning writer for the Bay Area News Group working with the business desk as a general assignment reporter. Over his 34 years in daily newspapers, he has traveled overseas and around the nation, covering wars and natural disasters, writing both breaking news stories and human-interest features. He has won numerous national and regional writing awards during his years as a reporter, 17 of them spent at the Miami Herald. In 1993, Pat shared with his colleagues a Pulitzer Prize for Public Service for the Herald staff's coverage of Hurricane Andrew and its aftermath.
Follow Patrick May @patmaymerc
For links see article source.....
Posted for fair use.....
http://www.mercurynews.com/2016/10/20/2-bay-area-earthquake-faults-found-to-be-connected/
The Mercury News
Two Bay Area earthquake faults found to be connected
A sign notifying people they are standing on the Hayward Fault stands at the children’s area at the Oakland Zoo in Oakland. New research published in the journal Science Advances on Wednesday found that the Hayward Fault may be linked to another fault. (File Photo)
By Patrick May | pmay@bayareanewsgroup.com
PUBLISHED: October 20, 2016 at 6:40 am | UPDATED: October 20, 2016 at 1:48 pm
*
Just in time for today’s Great California ShakeOut earthquake drills comes a newly published*study with a troubling finding:
Two of the Bay Area’s most infamous and potentially deadly earthquake faults may be linked, potentially packing a greater punch than even the 1989 Loma Prieta temblor.
The pair-up is troubling: once thought to be two miles apart under the bay, the Rodgers Creek Fault, running from near Santa Rosa into the San Pablo Bay, and the Hayward Fault, stretching from below San Jose through the Oakland and Berkeley hills into West Contra Costa County, may indeed form one 99-mile-long fault that could deliver a blow greater than the sum of its parts.
“This should be a reminder that folks in the Bay Area need to be prepared for a major earthquake,” said*Janet Watt,*research geophysicist with the U.S. Geological Survey in Santa Cruz, in an email this week to the AP. She’s one of the four authors of the study which appears this week in Science Advances.
This is not the first time these findings have been made public: In a story last January in this newspaper, Watt said “it does look like there is a good chance that the faults are connected.” But with the publication of her team’s findings, their research promises to resonate even more strongly among quake-wary residents of the San Francisco Bay Area.
Extent of the Hayward-Rodgers Creek fault zone shown in red. Black lines show other major faults. White box shows study area. Cities are marked with letters: AR, Alum Rock; H, Healdsburg; L, Livermore; O, Oakland; SF, San Francisco; SR, Santa Rosa.
The team’s underwater surveys revealed a previously unknown strand of the Hayward Fault that connects to the western section of the Rodgers Creek Fault. One reason why it has taken so long to determine the relationship between the two faults is because the bay is very shallow, which makes it hard to use a boat. Researchers floated instruments on pontoons.
Should the power of the two faults join forces, they are more likely to cause a magnitude-7.2 quake, about three times stronger than the magnitude-6.9 Loma Prieta quake, which in 1989 violently shook the Bay Area, killed 63 people and caused an estimated $6 billion in damage.
“The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults,” the authors wrote. “Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery.”
But now, the scientists say, sophisticated imaging tools looking beneath the Bay Area’s surface have unearthed a scary scenario:
“The Hayward and Rodgers Creek faults are directly connected at the surface—a geometric relationship that has significant implications for earthquake dynamics and seismic hazard,” says the article. “A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact.”
The findings were the result of work by Watt and her team in 2014 when they seismically mapped the earth under San Pablo Bay. Their search produced an image of a strand linking the two faults, she said. Until then the Rodgers Creek and Hayward faults had been thought to be independent but capable of influencing each other.
Related Articles
Earthquake alert issued for Southern California
Yet even as scientists fear the Hayward-Rodgers Creek fault zone could wallop the region with a powerful quake in the next 30 years, “the location and connectivity of the Hayward and Rodgers Creek faults remain uncertain beneath San Pablo Bay.”
*
The eastern span of the Bay Bridge after the Loma Prieta quake
So much of the earlier mystery remains, and the authors warn that “resolving this uncertainty is particularly important because the alternative fault models (fault stepover versus fault bend) have different implications for earthquake hazard.”And quake history is important, Watt said. “There hasn’t been a quake along the Hayward Fault since 1868.*There’s (geological) seismic evidence showing they may have ruptured together in 1700s or in two separate breaks within decades of each other.”
*
And for more information about today’s Great California ShakeOut, go here.
Credit: ScienceAdvances; U.S. Geological Survey
Sponsored Content
How Much Annual Retirement Income Will You Have? Find Out Here.
By
Retirement is probably the most expensive thing you’ll ever pay for.
Tags:*Earthquake
Patrick May Patrick May is an award-winning writer for the Bay Area News Group working with the business desk as a general assignment reporter. Over his 34 years in daily newspapers, he has traveled overseas and around the nation, covering wars and natural disasters, writing both breaking news stories and human-interest features. He has won numerous national and regional writing awards during his years as a reporter, 17 of them spent at the Miami Herald. In 1993, Pat shared with his colleagues a Pulitzer Prize for Public Service for the Herald staff's coverage of Hurricane Andrew and its aftermath.
Follow Patrick May @patmaymerc