Napa earthquake hastens calls for warning system

[Buster's Uncle]

Napa earthquake hastens calls for warning system
Associated Press
By ELLEN KNICKMEYER and SUDHIN THANAWALA  40 minutes ago



Engineers inspected buildings for structure damage while Napa residents and homeowners started the long clean-up and recovery process after Sunday's 6.0 earthquake. (Aug. 25)



NAPA, Calif. (AP) — The earthquake that jolted California's wine capital may have caused at least $1 billion in property damage, but it also added impetus to the state's effort to develop an early warning system that might offer a few precious seconds for residents to duck under desks, trains to slow down and utility lines to be powered down before the seismic waves reach them.

California's senior senator, Democrat Dianne Feinstein, joined a chorus of renewed calls on Monday for the quick deployment of a quake activity alert system such as the ones already in operation in Mexico and Japan.

"Officials in Washington and along the West Coast should partner with the private sector to make an interoperable earthquake early-warning system a reality, and we should do so as soon as possible before a much larger earthquake strikes," Feinstein said.

Such a system may be closer to reality than most Californians realize, though it's still years away. A bill signed by Gov. Jerry Brown last year ordered his Office of Emergency Services to develop a comprehensive statewide system and by 2016, identify sources of funding for it. An early-warning system would cost an estimated $80 million.

The office's director, Mark Ghiladucci said Monday that he pictures a network, financed with both private and public money, made up of a government "backbone" and supplemented with data from private sources in more remote areas.

"This is sort of the last mile out of the 20-year effort for scientists that have been working on this for us to pull it all together," Ghiladucci said. "California is unique. It is a long, complicated, highly populated state, and we have to have a system that is 100 percent reliable so that people can count on it."



The earthquake-damaged historic winery building dating from 1886 at Trefethen Family Vineyards leans Monday, Aug. 25, 2014, in Napa, Calif. The winery hopes to save the building that is in danger of collapse after San Francisco Bay Area's strongest earthquake in 25 years struck the heart of California's wine country early Sunday. (AP Photo/Eric Risberg)


Richard Allen, director of the University of California, Berkeley, Seismological Lab, said his lab received a 10-second advance warning of light shaking when the seismic waves from Sunday's quake arrived there. Allen is among the researchers testing the earthquake warning system that is not yet available for public use, but is envisioned as the basis for the state's system.

The magnitude-6.0 temblor was centered near the city of Napa and caused several injuries, left four mobile homes destroyed by gas-fed fires and damaged wineries, historic buildings and hotels. The area has experienced dozens of aftershocks since, the largest of which was a 3.9-magnitude quake that struck at 5:33 a.m. Tuesday about 7 miles south of the city of Napa.

There were no calls reporting damage or injuries, but the quake did rattle already frayed nerves.

"That's not just an aftershock. That's another earthquake to me," Krisha Reed told KTVU-TV after running out of her apartment. She suffered injuries in Sunday's quake.

Allen, of the UC Berkeley Seismological Lab, said even though Berkeley is about 40 miles from the quake's epicenter and did not experience any damage during Sunday's quake, in a more violent temblor, 10 seconds could have made a big difference.



Earthquake-damaged wine barrels are lined up after being removed from Napa Barrel Care Monday, Aug. 25, 2014, in Napa, Calif. A powerful earthquake that struck the heart of California's wine country caught many people sound asleep, sending dressers, mirrors and pictures crashing down around them and toppling wine bottles in vineyards around the region. The magnitude-6.0 quake struck at 3:20 a.m. PDT Sunday near the city of Napa. (AP Photo/Eric Risberg)


"A few seconds means that you can move to your safe zone, that you can get under that sturdy table; that way you are not going to be injured by falling fireplaces and ceiling lights. We see a large number of injuries resulting from these kinds of incidents."

The systems can't predict quakes, and are not effective at the epicenter, where the tremors go out almost simultaneously. The warning people receive — a few seconds to tens of seconds — depends on the distance from the epicenter.

Napa would have received at most a second of warning if California already had a system in place, said Thomas Heaton, a professor of engineering seismology at California Institute of Technology in Pasadena.

"It's important for people to keep this in perspective," he said. "It's a new kind of tool, but it's not a panacea."

Business owners in Napa spent Monday mopping up high-end vintages that spilled from barrels and bottles and sweeping away broken glass in the rush to get the tourist hotspot back in shape for the summer's final holiday weekend. Government and tourism officials assessing its economic and structural impact encouraged visitors to keep flocking to the charming towns, tasting rooms, restaurants and spas that drive the Napa Valley economy.



A worker removes an earthquake-damaged wine barrel from a barrel storage facility Monday, Aug. 25, 2014, in Napa, Calif. A powerful earthquake that struck the heart of California's wine country caught many people sound asleep, sending dressers, mirrors and pictures crashing down around them and toppling wine bottles in vineyards around the region. The magnitude-6.0 quake struck at 3:20 a.m. PDT Sunday near the city of Napa. (AP Photo/Eric Risberg)


While cleanup will take time and broken water mains remained a problem, they said, the worst damage and disruption was confined to the city's downtown, where a post office, library and a 141-room hotel were among more than 160 homes and buildings either deemed unsafe to occupy or enter. Two hotels and 12 wineries were still closed Monday, as well as gift shops, restaurants and other downtown businesses, Clay Gregory, president of tourism organization Visit Napa Valley, said.

"Clearly, we are concerned that people are going to see that it was a catastrophe, and it certainly wasn't good, but it wasn't a catastrophe by any means," Gregory said as workers at a shuttered downtown visitor's center updated lists of open wineries and surveyed hotels about cancellations. "The real story is that it has impacted a very small part of the valley."

Local officials have an early working estimate that Napa Valley suffered $1 billion in property damage, but they hope the long-term economic impact of the quake to businesses will be modest, Napa County Supervisor Bill Dodd said. August, September and October grape harvest represents the busiest time of year for both the valley's 500 or so vintners and the visitors who come from all over the world to see them work.

If people "think Napa is devastated, it's anything but devastated. We're only 24 hours out from an earthquake, and we're on our way back," Dodd said.

The Napa Valley Wine Train, which offers tourists a three-hour journey through 18 miles of wine country, canceled its service Monday but planned to resume trips Tuesday. Other tour operators said they were taking it one day at a time, tweaking their itineraries as wineries and their workers dealt with the damage.

At the famed Robert Mondavi Winery outside Napa, where visitors sat in a sunny outdoor tasting area sipping glasses of wine on Monday, gift shop supervisor Kevin Seeman said there had been only a small number of canceled reservations and that the people who worked there were more on edge than the patrons.

"A lot of the staffers are worried," Seeman said. "Some of them their homes are full of rubble; they are worried because they can't find their cats. The visitors seem not so worried about it all."

___

Thanawala reported from San Francisco. Lisa Leff in San Francisco and Scott Mayerowitz contributed to this story.


http://news.yahoo.com/napa-earthquake-hastens-calls-warning-system-070049508.html

[Buster's Uncle]

South Napa Earthquake Woke Up Many, Fitness Trackers Reveal
LiveScience.com
By Bahar Gholipour, Staff Writer  August 25, 2014 2:02 PM



Scientist at Jawbone look at the effects of the South Napa earthquake on people's sleep in several cities.



It might be possible to know how many people woke up during the South Napa Earthquake that struck 3:20 a.m. yesterday (Aug. 24) by looking at their fitness trackers.

The 6.0-magnitude earthquake that hit Northern California was the strongest to strike the region in 25 years. Data scientists at Jawbone, which makes the UP and UP24 fitness trackers, analyzed how the earthquake may have affected thousands of UP wearers in the Bay Area who track their sleep using the fitness devices, according to a statement from the company.

The results showed that 93 percent of UP wearers who were within 15 miles of the earthquake's epicenter — in the areas of Napa, Sonoma, Vallejo and Fairfield — suddenly woke up at 3:20 a.m. when the quake struck.

Farther out, about 25 to 50 miles from the epicenter in San Francisco and Oakland, only 55 percent of UP wearers woke up, while the rest seem to have slept through the shaking. In Sacramento and San Jose, which are 50 to 75 miles from the epicenter, 25 percent of UP wearers woke up, according to Jawbone.

Even farther out, in Modesto, Santa Cruz and other places between 75 and 100 miles from the epicenter, almost no UP wearers were awakened by the earthquake, according to their fitness tracker data.

The Jawbone UP is a wrist-worn device that can track users' movements during sleep, and provides a record of the time they spent in bed, as well as the time spent in deep and light sleep. These records give users a ballpark estimate of their sleep quality and enable them to track their sleep patterns over time.

The device also tracks people's steps when they are walking, and that's how Jawbone scientists know people actually woke up, and were not simply being shaken during their sleep by the quake. "Steps look a lot different than earthquakes," Brian Wilt, Jawbone's senior data scientist, told Live Science in a tweet. "We have to filter [people's] motion in cars, trains, etc. all the time."

The Jawbone data also showed that it took people a long time to go back to sleep, especially in the areas that felt the shaking the strongest. In fact, 45 percent of UP wearers living less than 15 miles from the earthquake's epicenter stayed up the rest of the night, Eugene Mandel, from Jawbone's data science team, said.


http://news.yahoo.com/south-napa-earthquake-woke-many-fitness-trackers-reveal-180235131.html

[Buster's Uncle]

Is There a Better Way to Measure Earthquakes?
The Atlantic
By Adrienne LaFrance  1 hour ago



Two hundred years ago, Missouri was rocked by an earthquake so severe it made the Mississippi River flow backward and set off church bells in Boston more than 1,000 miles away.

These details help convey the staggering scale and reach of what was a remarkable geologic event. Today, along with those accounts, we would also get a number: the magnitude of the earthquake. But that number is based on a logarithmic scale, and can be hard to grasp. 

Earthquakes aren't measured linearly, but in orders of magnitude. Which means a 6.1 magnitude quake like the one that shook Northern California over the weekend is about twice as big as the 5.8 earthquake that rattled Washington, D.C., in 2011—and nearly three times as strong in terms of the amount of energy it released. Some more context: The 7.0 earthquake that devastated Haiti in 2010 was eight times bigger than the Northern California quake, and released 22 times more energy. None of this jibes with the linear way people use numbers for most measurements in daily life.

Here's how Jesse Singal explained it over at New York magazine earlier this year:

On a linear scale, we know that four is twice as big as two and eight twice as big as four. This is what a casual observer of earthquake magnitude scales would expect: that an earthquake of 6.0 packs twice the punch of a 3.0. But no! In reality, a 6.0 quake releases 31,622.776 times as much energy as a 3.0 quake. And a 7.0 releases 31.622 times as much energy as a 6.0.

So why do geologists talk about earthquakes this way? Why not use a scale that operates more like the ones used to measure weight, or length, or temperature, or any number of other natural phenomena?

The answer, it turns out, begins in outer space. "My amateur interest in astronomy brought out the term 'magnitude,' which is used for the brightness of a star," said Charles Richter—the scientist behind the well-known scale of the same name—in a 1980 interview.

The Richter Magnitude Scale is the method of earthquake measurement widely used in the  United States last century. Richter's idea was to track the amount of energy released by a quake the way an astronomer would measure the brightness of a star. Each number on the magnitude scale indicated an earthquake 10 times stronger than the last—which means the quake strength between each increment of one on the scale grows as the numbers climb.

Today, earthquake magnitude is measured using another logarithmic system—usually called Moment Magnitude or just Magnitude—that's calibrated to the Richter Scale but can measure bigger quakes than the Richter Scale could. And while it might not be the most intuitive system, it's a far more useful one than a linear scale would be.

"The logarithmic magnitude scale also allows for comparison of earthquakes on relatively the same terms even though their impacts to society and structures ... can be quite different," Robert Williams, a geologist in the USGS Earthquake Hazards Program, told me in an email. "Compared to a linear scale the logarithmic scale provides an easy and more manageable way to represent this wide range of ground motion amplitude (often many orders of magnitude) and energy release for different quakes within an easily understandable range of numbers." 

Richter identified some of the reasons linear alternatives aren't really workable when he and colleagues established the scale in the 1930s. Again Singal: "If you rescaled things to a linear scale—such as how much energy is produced by a given quake—suddenly you’d be dealing with huge numbers for the big quakes. And huge numbers are another thing most people aren’t particularly good at grasping."

Besides, even though Richter apparently acknowledged that "logarithmic plots are a device of the devil," they're actually widely used, as geologist Williams reminded me. "Logarithmic scales are commonly used in other sciences, for example, the decibel scale in sound measurements and the pH scale in chemistry for rating acidity."

For now, at least, it seems we're stuck with charting earthquakes this way. And for those who find thinking logarithmically doesn't come naturally, USGS has a handy online calculator that shows just how different quakes compare with one another. ​


http://news.yahoo.com/better-way-measure-earthquakes-180903972.html

[Buster's Uncle]

What Caused California's Napa Earthquake?
LiveScience.com
By Becky Oskin, Senior Writer  23 hours ago



Damage in downtown Napa, from a 6.0-magnitude that struck Northern California on Aug. 24, 2014.



A strong, 6.0-magnitude earthquake jolted Northern California yesterday (Aug. 24) at 3:20 a.m. local time. The earthquake's epicenter was a few miles south of Napa Valley's renowned wineries, and the quake busted barrels and bottles of precious vintages. More than 170 people were injured, and 100 homes are now uninhabitable, the state Office of Emergency Services said Sunday.

In the first uncertain minutes, a seismologist at the U.S Geological Survey's Bay Area headquarters pinned the blame on the Franklin Fault, which has been inactive for thousands of years.

By morning, the sun lay bare what darkness hid: Buckled pavement and cracked curbs lined up along the West Napa Fault for up to 10 miles (16 kilometers). After inspecting the damage, California state geologist John Parrish declared that Sunday's earthquake occurred on the West Napa Fault, not the Franklin Fault. The USGS concurred, tweeting Sunday that the Browns Valley section of the West Napa Fault was the likely culprit.

The results are still preliminary, and geologists will make a definitive call in the next few days. However, the early false start highlights how both high-tech instruments and old-fashioned groundwork remain important in the aftermath of an earthquake.


Which fault?

Yesterday's earthquake struck near the Napa Airport, in the San Pablo Bay marshes. The USGS precisely located the epicenter in just a few minutes, thanks to the region's dense seismic monitoring network, said Tom Brocher, director of the USGS Earthquake Science Center in Menlo Park, California. But which fault was at fault?

Many suspects appear on state earthquake maps. One is the West Napa Fault, which stretches 35 miles (57 km) from the city of St. Helena south to San Pablo Bay, according to a USGS report published in 2008. Among a handful of other possibilities, the Franklin Fault also stands out. This fault begins near the epicenter of the recent quake, and then cuts south across San Pablo Bay.

West Napa or Franklin? That 4 a.m. guess blaming the Franklin Fault soon seemed wrong. As damage reports poured in, scientists zeroed in on the West Napa Fault's Browns Valley branch.

This fault traces the western margin of the Napa Valley and cuts through the Browns Valley neighborhood of Napa. Along with the damaged streets, many of the city's water main breaks were in the Browns Valley area, according to Napa Valley officials. The Browns Valley branch pierces the Napa River at Cuttings Wharf. Another strand of the West Napa Fault lies east of the river and runs through the Napa Airport.

Why it happened

The West Napa Fault is part of the huge fault zone extending outward from the San Andreas Fault, which lies about 31 miles (50 km) west of Napa Valley. The San Andreas marks the boundary where the Pacific and North American tectonic plates grind past one another. The West Napa Fault is sandwiched between two larger faults: the Hayward-Rodgers Creek Fault and the Concord-Green Valley Fault.



Map of Napa Valley region faults.


"The plate boundary is really quite wide and quite complicated, and the plate motion is accommodated by a wide network of faults," Brocher told Live Science.

The tectonic tension between the plates trickles inland to the West Napa Fault. An earthquake occurs when this built-up strain is unleashed. The fault parallels the San Andreas, and like the San Andreas, it is a series of slashes in the earth, not a single crack. (Each fault has more than one segment running in parallel.) Each fault is also of a type called right-lateral strike-slip, which means one side of the fault leaps horizontally to the right during an earthquake.

Within the last 11,000 years, the West Napa Fault has created cliffs and ridges called scarps, a sign of past seismic activity. But this fault has never jolted valley residents in historic times.

The last earthquake to rattle the Napa Valley struck on Sept. 3, 2000. This magnitude-5.1 earthquake occurred 10 miles (16 km) northwest of Napa, near Yountville, on a previously unknown fault.

No one knows how often earthquakes rumble through Napa Valley. The West Napa Fault and others nearby have never received the detailed detective work that geologists lavish on faults in the densely settled Bay Area. A 2008 estimate of Bay Area earthquake probabilities conducted by scientists and engineers for the state of California did not include the West Napa Fault.

"It is known to be an active fault, but it certainly has not been viewed as one of the major players in the Bay Area," Brocher said.

Napa's 6.0-magnitude earthquake is the biggest quake in California since the magnitude-6.7 Northridge earthquake in 1994, and the biggest in Northern California since the 1989 Loma Prieta earthquake, a magnitude 6.9.


Collecting clues

But the South Napa earthquake could have been worse. Only part of the West Napa Fault broke open. If the entire fault had ripped, the earthquake would have been more powerful.

"I have to say, as much as the earthquake was large and had a widespread impact, it's not as bad as it could have been," Mark Ghilarducci, director of California's Office of Emergency Services, said during a press conference Sunday.

Though the actual earthquake rupture only lasted four seconds, there was strong shaking in Napa because the valley floor is lined with soft river soils that amplify earthquake waves. Also, the fault zipped open from south to north, directing the earthquake energy toward the city. "It looks like it went northwest and up from the dot on the map that shows where the earthquake nucleated," Brocher said.

Early Sunday morning, geologists from the USGS, the California Geological Survey and local universities were recording the surface damage before road crews started their repairs. This information will help researchers understand the earthquake's progress during the brief seconds the fault opened and closed.

On the high-tech side, it will take a few more days to measure how much the valley moved during and after the earthquake, using GPS and satellite measurements. An initial GPS report indicated 4 inches (10 centimeters) of shift near the earthquake's epicenter, Brocher said.

Small earthquakes called aftershocks continue to strike along the West Napa Fault. These small quakes cluster along the fault zone and illuminate the hidden underground parts of the fault, and will help scientists nail down which fault caused the quake.

"The locations of the aftershocks indicate that it ruptured the West Napa Fault, but it is not clear yet which strand of that fault broke," said Felix Waldhauser, a seismologist at the Lamont-Doherty Earth Observatory in Palisades, New York. "Over the next couple of days we should have a better picture."

The earthquake is likely to bring new focus to Napa Valley's earthquake hazard. The California Geological Survey had already begun new studies on the Browns Valley branch earlier this year, and more researchers will likely begin studies analyzing the earthquake and its causes.

The quake also highlighted the most forward-reaching technology in California's quake arsenal.

The first jolt triggered the prototype earthquake early warning system at the University of California, Berkeley's Seismological Laboratory. The lab received a 10-second warning before the shaking started, said Lab Director Richard Allen. The warning could have been improved with an upgrade to the ShakeAlert system, which would have boosted the response time of the slowest seismometer by 2.5 seconds, Allen said. The state legislature approved a bill to expand the system statewide in 2013, but the Office of Emergency Services must find $80 million to pay for it.

"While the system clearly worked, the warning could have been twice as fast," Allen said.


http://news.yahoo.com/caused-californias-napa-earthquake-202350037.html

[Buster's Uncle]

BART got a 10 second warning before Sunday’s Napa earthquake. Why didn’t everyone else?
Gigaom
By Signe Brewster  1 day ago


Summary:
Earthquake detection is improving, and there is actually a California law that says the state needs to put an early warning system in place. But that has yet to happen on a wide scale.



Many historic buildings get damaged in a magnitude-6.0 quake. (Photo by Tayfun Coskun/Anadolu Agency/Getty Images)



At 3:20 a.m. on August 24, an alarm went off at Bay Area transit provider BART’s offices: An earthquake was approaching, and the shaking would start in 10 seconds.

By the time the tremblors reached BART’s tracks in the East Bay and San Francisco, they had become mild enough that no extra safety measures were necessary, BART board of directors member John McPartland said at a press conference Monday. But had the earthquake happened while trains were running at an intensity of a 3.1 earthquake or higher, the warning would have prompted trains traveling at 35 MPH or less to stop, and trains moving faster to slow.

It all would have happened automatically based on 12 earthquake sensors installed for BART as a part of ShakeAlert, an early warning system created by the University of California-Berkeley Seismology Laboratory, United States Geological Survey and other partners. Like a tornado or hurricane, it’s possible to predict the approach of an earthquake, and ShakeAlert’s 150 users knew the Napa quake was coming. Berkeley received a 10 second warning. Cities farther south received even longer. The system also predicted that the earthquake would have a magnitude of 5.7–fairly close to the 6.0 magnitude it was officially given.

“This is a great success for us. It’s certainly not the first,” UC-Berkeley Seismology Lab director Richard Allen said at the press conference. The system previously has warned of Los Angeles-area earthquakes.

ShakeAlert detects earthquakes via around 300 sensors scattered across California. They measure what are known as P-waves: non-destructive waves of energy that travel much faster than the S-waves earthquakes produce that cause shaking and damage. ShakeAlert spots P-waves by weeding out vibrations from trucks, machinery and other man-made sources. It determines the origin and size of an earthquake based on the shape of the P-waves.

So earthquake warning systems don’t actually predict an earthquake. They just spot the very first indication that one is happening and alert users before the destructive part begins. Long-range earthquake forecasting is a much more difficult task. Scientists believe San Francisco is long overdue for an earthquake on the scale of the 1906 tremblor that led to the burning of 80 percent of the city, for example, but can’t pinpoint exactly when that earthquake will occur.

Animals, it turns out, might be better predictors than us. A 2010 study found that toads seemingly knew about the 2009 L’Aquila earthquake in Italy days in advance, possibly due to changes in electric fields or gases in the air. But unless we begin keeping toads in our homes, we’ll have to make do with the precious few seconds P-waves afford us.



A car is seen covered in bricks following a reported 6.0 earthquake on August 24, 2014 in Napa, California. Justin Sullivan/Getty Images


So why didn’t every single resident in the Bay Area get that same warning as BART? The answer is funding.

It’s been law since 2013 that California needs to establish a state-wide earthquake early warning system. But the law states that funding won’t come from California’s general fund.

The damage from the Napa earthquake could exceed $1 billion. As many as 200 people were hospitalized with minor and serious injuries, according to the San Jose Mercury News. Interest in earthquake protection is now high, and Allen said there are several potential ways to secure funding. ShakeAlert is close to receiving government money in Sacramento, and people in other parts of the state can contact their legislators to express their support. The best bet is the $7.5 billion water bond that will be voted on in November; it contains funding for an earthquake warning system.

If it does go into effect, a state-wide system could be integrated into more than just transit systems like BART. A self-driving car could automatically stop before entering a tunnel and a factory could shutdown and protect any equipment that contains dangerous materials. Many of the fires that started after the Napa quake were likely caused by broken natural gas lines that could have been shut off by a warning system. Even the Napa Valley wineries, which lost millions of dollars of wine, could have benefitted from some sort of protective measure.

Most importantly, people would have had enough time to move away from heavy or sharp objects, potentially preventing a huge number of the injuries that occurred. Phones, computers, radios and tons of other types of devices could have awoken to deliver the warning to every single Bay Area resident.

“This is a critical need here in earthquake country,” Allen said. “People want this. We just need the necessary investment to complete ShakeAlert.”


https://gigaom.com/2014/08/25/bart-had-a-10-second-warning-before-sundays-napa-earthquake-why-didnt-everyone-else/?utm_medium=content&utm_campaign=syndication&utm_source=yfinance&utm_content=bart-had-a-10-second-warning-before-sundays-napa-earthquake-why-didnt-everyone-else_867545