• Japan's quake still poses puzzles

    Caltech

    A chart of the area between the Japanese island of Hokkaido and the Japan Trench shows the amount of fault slip due to the March 2011 earthquake. The red area denotes slip of 50 meters (196 feet) or more. The question mark represents the researchers' current lack of information about the seismic potential of the region south of last year's quake.

    By Alan Boyle, Science Editor, NBC News

    One year ago, the earthquake that struck Japan literally changed the spin of our planet and the length of our day — but today, the biggest mystery surrounding the event is what didn't happen: Why wasn't the Tohoku earthquake even bigger?

    "We really don't know what's going to happen in the future," said Thomas Heaton, director of Caltech's Earthquake Engineering Research Laboratory. "And by the way, one of the big questions nobody seems to be talking about is ... why was Tohoku so small? Where's the rest of it? Was this a foreshock? We don't know that. Honestly, it was mostly in the northern part of the [Japan] trench. The southern part of the trench doesn't seem to have gone."

    It may sound strange to talk about a magnitude-9.0 quake and tsunami as something that's mystifyingly small. But the way Heaton sees it, the unusual scenario that played out on March 11, 2011, shows how much we still have to learn about how earthquakes work. Moreover, it shows that scientists may not fully understand the mechanism of seismic shocks for the foreseeable future.

    "The most obvious lesson learned is to plan for the unexpected," Heaton said.

    Surprises from the Japan Trench
    Scientists have long known that the Japan Trench, where the oceanic Pacific Plate dives beneath the continental Okhotsk Plate, was seismically active. It's part of the "Pacific Ring of Fire" that runs like a horseshoe around the ocean's edge. But scientists and engineers thought the trench wasn't capable of generating earthquakes that big — and so they designed structures such as seawalls and nuclear power plants to fit what they saw as prudent probabilities.

    "The real problem is that currently there's a view among society, and engineers, that we design for a risk factor," Heaton said. "What's the hazard, and I will design according to the hazard. And once I've met certain design criteria, I have confidence that my structure will survive at some given level."

    So what happens when the big, unexpected event happens? Seawalls are breached. Airports are wrecked. Towns are wiped out. Nuclear plants are swamped. "They believed their risk models, and they shouldn't have," Heaton said.

    One year after Japan's earthquake and tsunami, NBC's Ian Williams reports from a serene wasteland in the fishing village of Otsuchi, which lies near mountains of debris.

    He said engineers should take more of a common-sensical approach to construction design, rather than focusing so much on  meeting the specifications dictated by risk analyses. "I think that we've really gotten ourselves off track there," Heaton said.

    Uncertainties abound
    It's tempting to think that Japan has had its "once-in-a-millennium" seismic shock, and that people can relax for the next 999 years. After all, last year's earthquake was big enough to shift Honshu, Japan's main island, as much as 13 feet to the east. It also gave Earth's axis a 6.5-inch readustment and shortened the length of the day by 1.8 microseconds.

    But Heaton said the geophysical shifts raise additional questions. Here's a potential biggie: Honshu has been subsiding for the past century, and the earthquake just added to the subsidence. That was unexpected, because seismologists assumed that an earthquake would release the crustal strain and result in an uplift.

    "We know we can't continue to go down at these rates forever, or Honshu would just disappear in a million years or so," Heaton said. Will the island slowly stop sinking and then start rising again? Or will the strain continue to build until another big earthquake releases it?

    "We don't know the answer to that, but it's a pretty important question," Heaton said.

    Last May, a team of researchers from Caltech and elsewhere analyzed the seismic data from before and after the quake, and found that significant slip was experienced along a 150-mile length of the Japan Trench fault — which is about half the length that would have been expected for a magnitude-9.0 event. They also reported that the conditions they saw in the area of the quake's epicenter before March 11, 2011, still exist today in the area to the south, known as the Ibaraki region.

    "It is important to note that we are not predicting an earthquake here," Caltech's Mark Simons, the study's lead author, said in a news release about the research. "However, we do not have data on the area, and therefore should focus attention there, given its proximity to Tokyo."

    Nasty surprises
    Just this week, Japanese researchers reported that Tokyo could be more vulnerable to a magnitude-7 quake in northern Tokyo Bay than they previously thought, and they said older structures should be reinforced to meet more stringent standards. "If a building narrowly fulfills the law's standards, its quake resistance is not high," the Daily Yomiuri quoted seismologist Takuya Nagae as saying.

    Heaton said it only makes sense to expect further surprises from seismological studies, including some nasty ones. "My experience as a human is that there's a good chance there's something we didn't know. ... It keeps coming up over and over again that there are major holes in our understanding of the system," he said.

    If that's the case, it's prudent to plan for the unexpected. And that concept may apply to more than seismology.

    "If you don't really know what's going to happen, what's the best strategy for dealing with life when you have all those uncertainties out there?" Heaton asked. "They're all over the place, like in the financial system. Or when are you going to die? Well, you could die from old age. Maybe you'll die from a heart attack. Maybe you'll die from bird flu. What's the risk of bird flu? ... You can't put a number on it. So what does that mean? Should we ignore bird flu? No, of course not. It means you should study it, and if there are easy things that society can do to minimize the chance of everybody getting bird flu, you should pursue them."

    Are those words to live by? Or is the view that we don't know when or where the next Big One will come just too unsettling? Feel free to weigh in with your comments below.

    More about the Japan quake anniversary:

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

  • The next wave in tsunami science

    PMEL / NOAA

    A false-color virtual globe, centered on the Pacific Ocean, shows the propagation of tsunami waves from their seismic source off the coast of Japan on March 11, 2011. Black, purple and red denote the highest waves.

    By Alan Boyle, Science Editor, NBC News



    Last year's earthquake and tsunami was a catastrophe for Japan — but a problem averted for Hawaii and the U.S. West Coast, partly due to luck and partly due to the success of long-range tsunami tracking. Now researchers are working to bring that success closer to home.

    If a similar ocean wave were to target the U.S. coastline in the future — and seismologists say that's only a matter of time — the emergency response should be much improved, thanks to the lessons learned from last March's super-tsunami.

    "Definitely there are a lot of lessons learned from a big event like that," Vasily Titov, director of the National Oceanic and Atmospheric Administration's Center for Tsunami Research, told me this week.

    Titov and his colleagues, who are based at the Pacific Marine Environmental Laboratory in Seattle, have focused for years on building better computer models to predict how tsunami waves will spread out from an undersea seismic shock like the one that rocked Japan. Tsunami trackers came in for a good deal of criticism after the 2004 Indian Ocean earthquake and tsunami, which killed an estimated 230,000 people in 12 nations. Since then, government agencies have worked together to fill in the gaps in an oceanwide network of deep-sea and surface-buoy sensors — and the upgrades paid off big time last year.

    Readings from a network of more than 50 buoys — including the federal governnment's Deep-ocean Assessment and Reporting of Tsunamis system, or DART —tracked wave heights after a magnitude-9.0 shift in the ocean floor set off a giant wall of water. The waves rose as much as 6 feet in open ocean. "Ten years ago, people would say, 'Oh, it's not possible to have a tsunami that high,'" Titov said. "That was the event that I was hoping not to see in my life."

    The computer model correctly predicted the level of flooding that Hawaii would face, seven hours after the earthquake. That provided enough time for a proper evacuation. "Deaths were avoided in Hawaii — I'm pretty confident about that," Titov said.

    The model also showed that there'd be only minor impact on the West Coast, due to the fact that the tsunami wave arrived at low tide. "If the West Coast had high tide during tsunami, it would have been much different," Titov said. "There would have been flooding all over the place."

    NOAA's Eddie Bernard narrates a video showing how the Honshu tsunami propagated outward from its center off the coast of Japan on March 11, 2011.

    The next wave?
    Titov happens to be headquartered in a region that could become ground zero for a future Japan-style tsunami. Studies have indicated that the Cascadia subduction zone, off the coast of Washington state, Oregon and British Columbia, is capable of generating the same kind of ocean wave. In fact, it's thought that such a shock took place off the West Coast more than 300 years ago, setting off a tsunami wave that reached all the way to Japan.

    Concerns about the next big wave, wherever it may come, is driving international efforts to track tsunami phenomena closer to the source. Last year's quake and tsunami killed nearly 16,000 people, with many of those deaths coming along the coast. If Japanese authorities had had a quicker assessment of the tsunami threat, they might have launched more intensive evacuation efforts in the first half-hour after the earthquake was detected. Thousands more lives might have been saved.

    "That has become the main challenge," Titov told me. "What can be done for this type of event?"

    To get a better grip on the local effects of a tsunami, a different kind of monitoring system is needed — a system that has scores of interconnected sea-floor stations, situated close to the source of a potential tsunami shift. The stations would have to be equipped with seismometers and pressure gauges, and send real-time data via satellite links for sophisticated analysis.

    Titov and his colleagues think they have come up with a solution to the challenge. "The system we developed worked better than expected," he said. "Detectors can be placed much closer to the source."

    Now Japan is making plans to deploy a new $400 million network of 154 sensor stations straddling the Japan Trench, which was the source of last year's seismic shock. That network is due to be put into place in the 2014-2015 time frame. Meanwhile, NOAA is planning to move some of its DART buoys closer to the Cascadia subduction zone and other seismic hot spots.

    Simulations suggest that the sensor system and upgraded analysis software can deliver an accurate assessment of local flooding in 30 minutes or less. That might still require authorities to go ahead with pre-emptive evacuations in some areas, even if the initial tsunami alert turns out to be a false alarm. "While the timing is challenging, the situation is manageable," Titov said.

    Maintaining the network
    At the same time, the existing network of tsunami-tracking buoys needs to be maintained. One of the problems that came to light after the 2004 tsunami was that some of the buoys in the DART network were prone to failure. One critic complained that the tsunami monitoring system was like "a fire alarm that cannot ring."

    "The problem is that even that strong array is budgetarily difficult to maintain," Titov said. "That has become the main challenge. We're trying to figure out how to maintain it."

    Titov said he found it hard to believe that it's already been a year since that horrible day — March 11, 2011, which is known as "3-11" in Japan. "My heart goes out to all the Japanese," he said. "A lot of our colleagues are from Japan. This has become very personal."

    That personal perspective sharpens Titov's desire to develop faster, better ways to predict the paths of the giant waves to come.

    "The fact that it's been a year already makes me a little nervous," he told me. "I want to move fast with this research so we're ready for the next tsunami."

    More about the Japan quake anniversary:

    For more about the future of tsunami forecasting, check out Richard Monastersky's report in the journal Nature.

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

  • Quake experts upgrade their alerts

    Earthquake researchers are studying a system that would provide a warning before shaking begins on the West Coast. KNBC's Patrick Healy reports.

    By Alan Boyle, Science Editor, NBC News




    One year after Japan's earthquake warning system was put to its sternest real-world test, U.S. researchers have built a system that could provide the same type of advance alerts for quake-prone California — the only problem is that they can't afford to get it ready for prime time.

    "I've got a system that works in my office," said Thomas Heaton, director of Caltech's Earthquake Engineering Research Laboratory. "It works for maybe 100 of us who are prototyping the system. It's been a grassroots effort where a number of scientists have cobbled it together as a demonstration project. But to turn it into a system where literally 50 million Americans would have everything linked into it? It's not ready for that."

    The California network, known as Earthquake Early Warning or ShakeAlert, has been in development since long before the magnitude-9.0 quake and tsunami that swept over Japan last March 11. It operates much like the Japanese network does: Readings from about 400 seismic monitoring stations around California are processed on a real-time basis, and when a quake is detected, computer software figures out how long it will take seismic waves to reach your location.

    The system takes advantage of the fact that two types of seismic waves emanate from the epicenter: The first waves to arrive are primary waves, or P waves, which are followed by slower secondary waves, or S waves. The S waves, which travel through Earth's crust at a speed of about 2 miles per second, produce more up-and-down motion and tend to be more damaging. The P waves serve as precursors, enabling experts to estimate the intensity and arrival time for the S waves that will follow.

    If the projected intensity is above the level you're worried about, your computer will start sounding an alarm and clicking through a countdown, as seen in the video above.

    "Right now it's working as well as you could hope for a kludged-together demonstration project from a bunch of professors," Heaton told me. He can adjust the controls downward to be alerted about minor quakes heading toward Caltech in Pasadena, or turn them up so high he can work undisturbed in his office.

    "You can go days without anything, and then a day comes when there's a cluster," he said.

    The Japanese system, which was developed at an estimated cost of $500 million, turned in a stellar performance during last year's quake. As the video below demonstrates, Tokyo residents had as much as 30 seconds' warning before the shaking began.

    Japanese video shows how an alert system provided advance warning of the magnitude-9.0 earthquake on March 11, 2011.

    Thirty seconds may not sound like much warning, but it's enough time to shut off gas mains and issue a warning to take cover. In Japan, the warnings are flashed via radio and TV, as well as through computer links and mobile phones. Automated broadcast alerts can be set to turn on a car's emergency flashers and warn drivers to slow down and pull over. The same principle is applied to safeguarding Japan's extensive rail system: Thanks to automated warnings, two dozen trains that were operating in the earthquake zone on March 11 were brought to a halt within seconds, with no reports of serious injuries or damage.

    Bugs in the system
    During last year's catastrophe, the biggest problem had to do with the fact that the closer residents were to the quake's epicenter, the less warning they received. Another issue was that the complexity of the initial seismic shock and the aftershocks caused the  system to become overloaded, leading to a temporary shutdown.

    Heaton and his colleagues are encountering similar bugs in the California system. "They're always being engineered to be better systems and less buggy, but we'll never eliminate all the bugs," he said. Right now, the team is working on an Android app version of ShakeAlert. Even the app would be unsuitable for mass distribution, however.

    "The technology exists to deploy it, but strategically, I don't see how we could ever support it," Heaton said.

    Going public with ShakeAlert would require a more concerted effort, backed by the expertise and funds that are typically associated with federal government agencies such as the U.S. Geological Survey. So far, the USGS has spent about $2 million on ShakeAlert, and the Gordon and Betty Moore Foundation is backing the research with $6 million in contributions to Caltech, the University of California at Berkeley and the University of Washington over the next three years. Other supporters include Google.org and Deutsche Telekom's Silicon Valley Innovation Center.

    The California Integrated Seismic Network estimates that a statewide quake warning system would cost about $80 million over five years, while the cost of a similar system for the Pacific Northwest has been estimated at $70 million. But it might take additional funding to get the system as fully linked in with society as Japan's system is now.

    "Ultimately, when it does run, you don't want university professors running it," Heaton said, with a tone of amiable self-deprecation. "We're the least reliable people to run something like that."

    Realistically, will ShakeAlert ever be ready for prime time? Heaton thinks it might take more than a catastrophic earthquake on the other side of the world to get Americans motivated about earthquake alerts at home.

    "My experience at this point in my life is that it's hard to get people to focus on things like this unless something bad happens," he said. "It's been really peaceful and quiet in the western U.S. for quite some time now. ... We're very concentrated on our own issues. We were shocked by what happened [in Japan], but not enough to actually do something."

    Caltech's demonstration of the Earthquake Early Warning System's computer software simulates a countdown for seismic waves (in yellow and red) spreading outward from a theoretical magnitude-7.5 earthquake on California's Elsinore fault line toward Los Angeles.

    Longer-range prediction?
    If it's hard to put in a system based on well-tested geophysics that provides a warning just seconds in advance of the Big One, it's a lot harder to extend the lead time to hours, or days. But people keep trying.

    "One prediction that we have learned to make following earthquakes, and this one is a very strong prediction, is that several people will claim to have predicted the earthquake," Heaton joked.

    Some researchers are trying to determine whether a statistical analysis of earthquake clustering can lead to better assessments of the chances that a big earthquake will follow smaller tremors. This month's issue of Physics World looks into the prospects for short-term probabilistic forecasting, as well as the controversy surrounding the researchers who didn't predict the deadly 2009 L'Aquila earthquake in Italy (and are now facing manslaughter charges).

    Heaton is doubtful that statistics could ever predict the onset of future quakes with the kind of reliability people expect. He noted that 50 percent of all earthquakes have foreshocks, and one quake out of 20 turns out to be a foreshock for a larger quake. "We can say, yeah, earthquakes come in clumps, but to get more particular and specific — personally, I don't think it's very helpful," he said. "What are people going to do with that information, anyway?"

    It's possible that some as-yet-unknown mechanism might provide advance indications that a big quake is coming. "There are interesting observations that seem to be reliable about phenomena that are totally mysterious to us," Heaton acknowledged. "Many of them concern electrical phenomena."

    Heaton even keeps an open mind about claims that animal behavior can be analyzed to predict future earthquakes.

    "I think we know some things that animals are unlikely to do — that is, pick up vibrations from the earth," he told me. "There may be other things out there that are happening that we don't understand very well. So I'm not going to say 'never' to something like that. But the more we think about the problem, the more we recognize that once an earthquake starts, at some point, trying to predict how big it will get before it stops seems to be a particularly difficult dynamics problem."

    More about the Japan quake anniversary:

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

  • Tsunami awes even the experts

    NOAA Center for Tsunami Research

    This graphic shows how waves generated by Japan's Honshu earthquake propagated across the Pacific Ocean, based on computer models. The different colors indicate different wave heights, as indicated by the key at lower right. Click on the graphic to watch a video showing the progress of the waves.

    By Alan Boyle, Science Editor, NBC News

    Seismic experts have long known that Japan’s complex undersea fault system is capable of unleashing great waves, but today's 8.9-magnitude quake was the most violent shock to hit the nation in the past century. And tsunami geologist Jody Bourgeois of the University of Washington was there to feel it for herself, on the Japanese island of Hokkaido.

    "The shaking didn't seem really strong, but it just kept going," she told me today during a Skype phone call. "I felt like I was seasick, which was really strange."

    Bourgeois is working with other seismic experts this winter at the University of Hokkaido in Sapporo, about 300 miles north of the quake's epicenter, and she's been keeping track of Japan's recent spate of seismic activity — including a 7.2 quake that struck off the Japanese coast on Wednesday.

    "I was sitting at my desk today, not really thinking we're going to get another earthquake, and then the room started to move," she said. "I didn't hear any people suggest that the 7.2 might be a foreshock. ... But now you realize that those were just the forerunners."

    NBC News' Tom Costello on the tsunami's cause.

    The quake, which ranks as the world's fifth-strongest seismic event of the past century, was centered near the southern end of an undersea subduction zone that extends from Russia's Kamchatka Peninsula and the Kuril Islands to the Japanese islands. Such a zone, where one tectonic plate dives beneath another, is a classic generator of tsunami waves.

    "Japan's very complicated because they've got several different plates coming together here," Bourgeois explained.

    Specifically, the quake occurred "in the subduction zone of the Japan Trench where the Pacific Plate subducts under the Honshu island of Japan, part of the Okhotsk Plate, at a rate of about 8 centimeters per year," Jayanta Guin, senior vice president of research for AIR Worldwide, said in an advisory.

    Quake history goes back centuries
    Paul Caruso, a geophysicist at the U.S. Geological Survey, said the quake occurred in one of the world's most seismically active regions. "That area has had nine earthquakes above magnitude 7 since 1973," he said.

    An undersea quake measuring 8.2 to 9.0 in magnitude occurred in the same subduction zone off the coast of Kamchatka in 1952, generating a Pacific-wide tsunami that caused considerable damage and loss of life in Russia. Japan's deadliest quake, a 7.9 shock that killed more than 140,000 people in 1923, occurred south of today's epicenter on the main island of Honshu.

    Going farther back, Bourgeois said core samples indicate that Japan's Sendai Plain was hit by a strong earthquake and tsunami back in the year 869. Some experts believe this was the strongest seismic disturbance to hit Japan in recorded history.

    The same area, including Sendai's airport, was hit the hardest by today's quake. "It's been 1,200 years since they had one this large," Bourgeois said.

    Other danger zones
    Bourgeois said the same kind of offshore subduction zone was implicated in the magnitude-8.8 earthquake that did so much damage a year ago. A stronger subduction seaquake, pegged at magnitude 9.1, caused the tsunami that swept through the Indian Ocean in 2004, causing more than 200,000 deaths around the Pacific Rim.

    Just last year, seismologists reported that the Bourgeois' home base — the Pacific Northwest — is vulnerable to the same kind of earthquake and tsunami. The 680-mile-long Cascadia fault has been dormant for 300 years, and seismologists say there's an 80 percent chance that the portion of the fault off southern Oregon and northern California could produce a megaquake in the next 50 years.

    The Planetary Society's Bill Nye discusses the tsunami's widespread impact.

    Aftershocks have been continuing in Japan, more than 12 hours after the 8.9 shock occurred, and they may continue for days or weeks longer. "We can expect a lot of aftershocks," Caltech seismologist Kate Hutton told MSNBC.

    Bourgeois doesn't intend to stay holed up in her office. "I know at least one group that's going out tomorrow to the coast," she said. But she also doesn't intend to get in the way.

    "We go out basically after a tsunami, when people are safe and you're not going to interfere with the local rescue efforts," Bourgeois said. "We're interested in everything — what kind of damage the tsunami did, how high the currents were. I'm interested in what kind of record the tsunami left behind, and Japan is very well set up for these kinds of surveys."

    More on the Japan quake and tsunami:

    Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about Alan Boyle's book on Pluto and the search for planets, check out the website for "The Case for Pluto."