News this Week

Science  06 Sep 2013:
Vol. 341, Issue 6150, pp. 1048

You are currently viewing the .

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

  1. Around the World

    1 - U.S. East Coast
    Virus Culprit in Dolphin Deaths
    2 - Rome
    Scientists Named Senatore a Vita
    3 - Washington, D.C.
    Consent Rules at Issue After Preemie Controversy

    U.S. East Coast

    Virus Culprit in Dolphin Deaths


    A measleslike virus killed hundreds of dolphins this summer.


    A measleslike virus appears to be the chief cause of the droves of dead dolphins that washed ashore along the U.S. East Coast this summer, researchers announced on 28 August. Since 1 July, 333 bottlenose dolphins have been recovered from beaches between New York and North Carolina—10 times the number usually recovered at this time of year.

    In early August, the National Oceanic and Atmospheric Administration (NOAA) declared an Unusual Mortality Event, freeing up federal funding for NOAA's Marine Mammal Health and Stranding Response Program (MMHSRP) to retrieve and assess the mammals' remains. The team used molecular techniques to probe for the virus as well as traditional examinations of the dead animals' lungs, brains, and lymph systems. The culprit appears to be a type of morbillivirus, a group that includes viruses that cause measles in humans and distemper in dogs.

    Morbillivirus was also responsible for a 1987 die-off that killed more than 700 dolphins. Wild dolphins exposed during that epidemic likely developed immunity to the virus, but animals born since 1987 are probably susceptible, says MMHSRP head Teri Rowles. The epidemic will continue until the number of susceptible animals dwindles, researchers predict.


    Scientists Named Senatore a Vita

    Two well-known Italian scientists have been appointed "senator for life" by President Giorgio Napolitano to honor their contributions to society. Physicist Carlo Rubbia, 79, and brain stem cell biologist Elena Cattaneo, 50, received the honor along with conductor Claudio Abbado and architect Renzo Piano on 30 August. Senators for life—of which there are now six—have the same voting rights as the 315 elected members of the Italian Senate.

    Rubbia shared the 1984 Nobel Prize in physics with Simon van der Meer and is still active at CERN in Geneva, Switzerland. In addition to her research, Cattaneo is active in outreach and in public debates, including an ongoing fight against an unproven stem cell therapy in Italy (

    The Italian scientific community is cheering the announcement. "The appointment of senators for life makes us proud as researchers and confirms the attention of the President of the Republic for the world of scientific research," said Italian National Research Council President Luigi Nicolais in a press release.

    Washington, D.C.

    No go?

    Preemie therapies may get new consent rules.


    Consent Rules at Issue After Preemie Controversy

    In the wake of a controversial study involving premature infants, the U.S. government is considering changing how biomedical researchers inform patients about the risks of clinical experiments. The controversy—which put some neonatal research on hold for several months—was the subject of a 28 August hearing held by the U.S. Department of Health and Human Services.

    The U.S. Office for Human Research Protections threatened to sanction 23 universities for failing to adequately disclose the risks of death and blindness posed by the so-called SUPPORT trial, which compared oxygen therapies provided to 1316 premature infants (Science, 19 April, p. 254). But it backed off following complaints from researchers, saying the issue needed more discussion (Science, 14 June, p. 1270). At the meeting, bioethicists argued that researchers should be able to waive some consent requirements if a study—such as SUPPORT—involves providing patients with standard care they might receive anyway. But a number of parents involved in the trial said they never would have agreed if they'd been told about all the risks.

  2. Newsmakers

    Science Wins Keck Prize

    Science magazine has won one of four 2013 Communication Awards from the National Academy of Sciences, National Academy of Engineering, and Institute of Medicine. The annual awards, supported by the W. M. Keck Foundation, recognize excellence in reporting and communicating science, engineering, and medicine to the general public. Each award comes with a $20,000 prize.

    Science was honored in the magazine/newspaper category for four articles from a special issue on human conflict (18 May 2012). The writers are Eliot Marshall, for "Parsing Terrorism"; Elizabeth Culotta, for "Roots of Racism"; Ann Gibbons, for "The Ultimate Sacrifice"; and Greg Miller, for "Drone Wars." The awards committee described the collection of stories as "an articulate, wide-ranging examination of what social scientists have learned about human violence, conflict, and terrorism."

    The other 2013 winners are: David George Haskell, for his book, The Forest Unseen; Joanne Silberner, David Baron, and PRI's The World, for four radio pieces on "the hidden toll cancer takes in impoverished nations"; and an online series in USA TODAY on the toxic legacy of abandoned lead factories.

    UC Davis Neurosurgeons Resign



    Two University of California, Davis, neurosurgeons who tried to treat three people with terminal brain cancer by inserting gastrointestinal bacteria into their brains have resigned after internal investigations found that they failed to follow ethical guidelines governing medical research. Paul Muizelaar, former head of the neurosurgery department, retired and left the university in June; colleague Rudolph J. Schrot announced his resignation this summer, effective 31 August.

    In 2010 and 2011, Muizelaar and Schrot applied live bacteria to the patients' open head wounds, based on observations that postoperation infection can prolong life in patients with glioblastoma, the most common and deadly form of brain tumor. One individual survived for a year; the other two developed sepsis and died within weeks of surgery.

    Although all three consented to the procedure, the investigations, which began in 2011, found that, among other infractions, the physicians violated university policy by taking steps to patent the treatment without proper approval—crossing a line between "innovative care," which allows for untested treatments in dire circumstances, and more strictly regulated medical research. The surgeons maintain they were acting in the interests of the patients, expected to live no longer than 15 months without treatment.

  3. Random Samples

    Sharper View Reveals Earth's Innards


    By probing thousands of kilometers of solid rock with seismic waves, seismologists have found a new kind of deep-Earth feature. The hottest rock—such as the plume rising through the mantle beneath Hawaii—has been particularly hard to image, driving a decades-long debate over how deep the sources of such hot spot plumes actually are.

    Thanks to powerful computers, however, seismologists can now spot new features using hot rock's effect on the wiggles of seismic waves—not just the waves' speed, as in earlier seismic imaging. Seismologist Scott French of the University of California, Berkeley, and colleagues report online in Science this week that by using this "full-waveform inversion" technique, they have traced the Hawaiian plume (yellow) to a depth of at least 1000 kilometers. That suggests plumes span the entire 2900-kilometer-thick mantle, not just its uppermost layer as many scientists have contended.

    The new imaging also reveals long "fingers" streaked across the Pacific 250 kilometers to 400 kilometers down (red)—apparently hot rock from the plumes flowing perpendicular to midocean ridges, where new ocean tectonic plates form.


    The chairman of the U.S. House of Representatives science committee says that the Environmental Protection Agency (EPA) isn't giving him the health and air pollution data he demanded in a controversial 1 August subpoena (Science, 9 August, p. 604), and that the agency now stands in default. "You did not provide … anything new," Representative Lamar Smith (R–TX) wrote on 3 September to EPA chief Gina McCarthy. Smith set a new deadline of 30 September.

  4. Boxed In

    1. Adrian Cho

    In a year of triumphs for their reigning models, cosmologists and particle physicists yearn for something new that they can't explain.

    Picture perfect.

    Standard cosmology accounts for every ripple in the cosmic microwave background.


    For cosmologists, it was the most eagerly awaited result in a decade—and to some, an enormous letdown. This March, scientists working with the European Space Agency's Planck spacecraft presented the best study yet of the afterglow of the big bang, the so-called cosmic microwave background (CMB). Since the 1990s, measurements of the microwaves had confirmed that the cosmos burst into existence instantaneously and revealed how much matter and energy it contains. Cosmologists hoped Planck would provide even deeper insights.

    Planck did everything it was supposed to do. Launched in 2009, it measured tiny variations in the temperature of the CMB across the sky with exquisite precision. The results were a near-perfect fit to what theory predicted. And that was the problem: "There's no evidence that there's new physics required beyond what we knew before," says George Efstathiou, a cosmologist at the University of Cambridge in the United Kingdom and member of the Planck team.

    Cosmologists aren't alone in feeling stymied. For decades, particle physicists have struggled in vain to find something their own standard model cannot explain—with one notable exception (see sidebar, p. 1058). Last year, physicists discovered a particle called the Higgs boson, the last missing piece in that master theory, and this year they confirmed that the Higgs has the basic properties predicted by the standard model. Many would be happier if it didn't. "Everybody would say, 'Yay!'" says Robert Plunkett of Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois.

    Cosmologists and particle physicists haven't explained everything. Neither of their standard models, for example, sheds any light on origins of the mysterious dark matter whose gravity binds the galaxies or the bizarre dark energy that's accelerating the expansion of the universe. Still, what the models do explain, they explain so well that scientists find themselves explicitly struggling to poke holes in their own theories. "We know that they're incomplete," Efstathiou says. "So you just have to push until the models crack—and they will crack."

    But where? Theorists have dreamed up all sorts of wild theories beyond the standard models. But, practically speaking, experimenters point to a handful of most-promising spots in which to dig for something new—although none guarantees a treasure.

    The Higgs and what else?

    Weight check.

    A Higgs boson should gain mass by turning into a top quark and an anti-top quark and back into a Higgs (inset, top). Physicists at the LHC (pictured) suspect a new particle counters that effect (inset, bottom).


    For particle physicists, the question is simple: Can they find something new besides the Higgs boson? If so, it is most likely to appear in the birthplace of the Higgs itself: the 27-kilometer-long Large Hadron Collider (LHC) at CERN, near Geneva, Switzerland. Since it started taking data in 2010, the LHC has collected only 1% of the total expected by 2030. And some physicists say the discovery of the Higgs itself suggests other new particles will turn up in the 99% to come.

    The argument stems from the role of the Higgs. Ordinary matter consists of a handful of particles: the up quarks and down quarks that form the protons and neutrons in atomic nuclei, the electrons that flesh out the atom, and the neutrinos that emerge in nuclear decay called beta decay. These particles have two sets of heavier cousins that can be blasted into fleeting existence with atom smashers. The standard model describes how such particles interact through three forces: the electromagnetic force, which creates light; the strong force, which binds quarks; and the weak force, which causes beta decay. (The theory doesn't include gravity.)

    But there's a catch: Assigning masses to the particles spoils the mathematical symmetries on which the whole theoretical construct depends. So somehow the particles must create their own mass by interacting with one another.

    That's where the Higgs comes in. Physicists assume the vacuum contains a field a bit like an electric field. Particles interact with that "Higgs field" to gain energy and, thanks to the equation E = mc2, mass. Just as an electric field consists of quantum particles called photons, the Higgs field consists of Higgs bosons lurking "virtually" in the vacuum. When physicists blasted the Higgs out of hiding, they proved nature uses this scheme.

    That feat also suggests more particles await discovery. In a bit of feedback, particles popping in and out of the vacuum should affect the Higgs, and standard model particles should make its mass soar a quadrillion times higher than is observed. Either that or a certain parameter must be fine-tuned to 23-digit precision to cancel out the excess. Such a coincidence is far-fetched, physicists argue. Instead, they say, new particles should exist that would counteract the effect in a more "natural" way.

    In particular, something must exist to counteract the one standard model particle that interacts with the Higgs most powerfully, the weighty top quark. "The argument is really 'We've got to find a partner to the top quark,' " says Joseph Incandela of the University of California (UC), Santa Barbara, spokesperson for the team working with the CMS particle detector at the LHC, which spotted the Higgs. Such particles should be within the LHC's reach, says Beate Heinemann of UC Berkeley, a deputy spokesperson for the team working with the ATLAS detector, which also spotted the Higgs. "If they're not light enough so that we can see them, then they're also so heavy that they won't help with the problem," she says.

    Some physicists say that this naturalness argument has had its day. Decades ago, they note, the same argument spawned a concept called supersymmetry, which posits for each known particle a massive "superpartner." Yet collider experiments haven't turned up a single superpartner, says Guido Altarelli, a theorist at the University of Rome (Roma Tre), so the whole idea needs a rethink. "If you ask me whether there will be new physics at the LHC, I don't know," Altarelli says. "However, based on what we have already seen, I strongly suspect the answer is no."

    Physicists should know in a few years. The LHC is undergoing repairs that should nearly double its energy when it comes back on in 2015. A couple of years' worth of data should then tell physicists if there's anything within the collider's reach.

    If nothing turns up, researchers may have to seek new physics in more precise measurements of familiar particles. For example, the LHC feeds a smaller detector called LHCb that studies particles called B mesons, which contain a hefty bottom quark and a lighter antiquark. Those particles' properties are affected by other particles popping in and out of existence within them. So if they stray too far from the standard model predictions, the discrepancies could be a sign of new particles at work—possibly ones too heavy to be produced by the LHC.

    "You have at least an equal chance to see new physics in these precision experiments as you do directly at the LHC, maybe even more," says Hassan Jawahery, an LHCb member from the University of Maryland, College Park. Figuring out what you've found may be harder, however.

    Filling in the known unknowns

    An equally fruitful place to hunt for new physics is the universe at large. Some cosmologists, too, feel they have reached a stalemate with their own standard model—but unlike the standard model of particle physics, theirs is tantalizingly incomplete.

    Known as ΛCDM (pronounced "lambda CDM"), the model gives a simple recipe for the cosmos: 5% ordinary matter, 27% cold dark matter (the CDM), and 68% dark energy. (The "Λ" stands for the simplest version of dark energy.) Within the first 10−32 seconds, it holds, the universe doubled and redoubled its size 60 times in a faster-than-light growth spurt called "inflation," which pulled space geometrically "flat" like a taut bedsheet. Inflation also hugely magnified tiny quantum fluctuations in the universe's density, into which dark matter gravitated to form a "cosmic web" of vast filaments and clumps. Ordinary matter settled into the clumps to form the galaxies.

    ΛCDM fits the data—including the latest results from Planck—with breathtaking precision, but as a theory many find it wanting. It assumes only generic definitions of ingredients such as dark matter and dark energy (for example, dark matter is matter that doesn't interact with radiation) and doesn't say what they really are. "It's not a theory, it's math," says Adam Riess, a cosmologist at the Space Telescope Science Institute in Baltimore, Maryland. "I don't find it that satisfying that the math is simple."

    The gaps may open an opportunity. For example, inflation is essentially a useful "just-so story" that explains the flatness and near-uniformity of the universe. But close study of the CMB could help reveal what drove inflation—and the answer could point to physics beyond our current understanding.

    The microwaves in the CMB are polarized, like light reflecting off a lake. And gravity waves rippling through the universe during inflation should have left swirls known as "B modes" in the pattern of polarization across the sky. The strength of the swirls should reveal the energy density of the universe during inflation and give theorists their first solid data on the quantum process that caused the blowup. A half-dozen teams, including Planck's, are racing to spot such "primordial" B modes.

    Others hope to decipher dark energy, perhaps the biggest mystery in all of physics. Cosmologists discovered it 15 years ago when they used stellar explosions called type Ia supernovae to trace the history of the universe's expansion. In shocking contrast to expectations, they found that the expansion is speeding up, as if powered by some form of space-stretching energy.

    The key question is whether that dark energy is a property of space itself—a "cosmological constant," which Einstein denoted Λ—or something in space. To tell the difference, cosmologists want to know how the density of dark energy has changed over cosmic time. If dark energy is part of space, then its density should have remained constant. If it's something in space, then its density may have fallen as space expanded. The difference is captured in a single parameter, w, which should be −1 for a cosmological constant and something like −0.9 for something else. "Our fondest hope is that we can give one more clue to the theorists," Riess says. "What if w isn't equal to −1? That would be pointing in a direction."

    Planck may have already done a little pointing, Riess says. Its data yields a value for the expansion rate of the universe that differs slightly from the value measured directly by studying relatively nearby stars and galaxies. That could be a clue that dark energy has changed and isn't a cosmological constant, he says, although the discrepancy is too small to stake a claim on.

    Other cosmologists are probing dark energy by looking at how structures such as galaxy clusters grew over time—a process slowed by dark energy's space-stretching effect. They are eager to see how the results fit with those from other methods such as supernovae, says Marcelle Soares-Santos, a Fermilab physicist working on the Dark Energy Survey, a 5-year study using the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. If dark-energy measurements from supernovae and from structure growth disagree, then gravity might behave differently on different scales, and dark energy could be an illusion produced by scientist's misunderstanding of gravity.

    Common ground: stalking dark matter

    Perhaps the most fertile place to advance both particle physics and cosmology is in the area where the fields explicitly overlap: the search for dark matter. For 80 years, astronomers and cosmologists have seen its gravitational fingerprints. Now, physicists hope to spot particles of the stuff floating about.

    Dark matter could consist of so-called weakly interacting massive particles, or WIMPs: hypothetical beefy bits of matter that interact with ordinary matter only through the feeble weak force. The idea of WIMPs was born in 1980s, when theorists noted that if the infant universe spawned such particles, then just enough of them should linger now to provide the dark matter—provided they weigh between about 10 and 1000 times as much as a proton. Known as the "WIMP miracle," that coincidence helped make WIMPs the leading dark-matter candidate.

    Scientists hope to detect WIMPs in several ways. Perhaps the LHC will blast them into existence—although it hasn't yet. Or astrophysicists hope to spot them colliding in space and annihilating one another to produce other particles. In 2008, physicists with an Italian satellite experiment called PAMELA observed an excess of high-energy positrons that could come from such annihilations—although the positrons could also be coming from a more mundane source, such as a pulsar.

    Most directly, physicists hope to see passing WIMPs as they ping off atomic nuclei in sensitive particle detectors. "I'm biased, but I still believe that the direct search for dark matter is one of the most promising ways we can look for how the standard model is broken," says Richard Gaitskell, a physicist at Brown University who works on a detector called LUX at the Sanford Underground Research Facility in Lead, South Dakota.

    Teams have been leap-frogging one another in building bigger and more sensitive detectors deep underground, where they're shielded from ordinary radiation. Researchers with the Cryogenic Dark Matter Search (CDMS) are running a detector filled with 10 kilograms of germanium in the Soudan mine in Minnesota. The LUX detector contains 370 kilograms of liquid xenon and should soon start taking data. Next year, the XENON team will turn on its new 1-tonne detector in Italy's subterranean Gran Sasso National Laboratory. Bigger devices are in the works.

    That race is entering an intriguing phase, says Neal Weiner, a theorist at New York University in New York City. WIMPs ought to interact with ordinary matter primarily in one of two ways: either by exchanging a quantum particle called a Z boson or by exchanging a Higgs boson. Experiments have ruled out the stronger Z boson process, but the Higgs exchange regime remains. "That's right where we are," Weiner says. "That's the regime that the current experiments are probing."

    In April, the CDMS team reported three events that could be signs of WIMPs a few times as massive as a proton. And for more than a decade, researchers with the DAMA experiment in Gran Sasso have claimed a signal of such light WIMPs. But those results remain to be confirmed, and the most likely mass range is still a few hundred times the mass of a proton, says Blas Cabrera, a CDMS team member from Stanford University in Palo Alto, California. The tonne-scale detectors now being planned should be sensitive to those masses, Cabrera says. "Probably 5 years from now is when we will have some more clarity," he says.

    The unexpected

    Particle physicists and cosmologists have no assurances that any of the possibilities will come to pass. If nothing pans out, some acknowledge, they could find themselves simply verifying their prevailing theories over and over again. "It could easily happen that we come up against the limit of our understanding," says Saul Perlmutter, a cosmologist at Lawrence Berkeley National Laboratory in California.

    Still, Perlmutter says he's optimistic that more breakthroughs will come in unexpected ways—as one did 15 years ago, when he and others first detected dark energy. "Pushing to see new regimes of the universe has been one of the most productive games we've played," he says, "and not because you get the results you're after, but because you find things you didn't expect."

    Daniel Eisenstein, a cosmologist at Harvard University who is studying the large-scale structure of the universe, agrees. "I guess the question is, will we be asking the same questions 20 years from now?" he says. "And I think there is every possibility that we'll be on to some significantly different threads."

  5. The Unruly Neutrino

    1. Adrian Cho

    Neutrinos flout the rules of particle physicists' standard model, but researchers are already deciphering their tricks.


    To detect even a few neutrinos, physicists need huge detectors such as Japan's Super-Kamiokande, which holds 50,000 tonnes of water.


    One clan of particles shamelessly flouts the rules of physicists' standard model: neutrinos. The theory says that they shouldn't have mass. Yet they do, and from the perspective of the theory, they misbehave wildly. "In neutrino physics there are places where you could have 10, 20, or 50% deviations from the standard model," says Patrick Huber, a theorist at the Virginia Polytechnic Institute and State University in Blacksburg. For those seeking new physics, "that makes it a worthwhile place to look."

    Born of a type of nuclear decay, neutrinos interact with matter so weakly that they can easily zip through a light-year of lead. They come in different "flavors," and in 1998, physicists working with the Super-Kamiokande detector in a mine near Hida, Japan, showed that neutrinos generated when cosmic rays strike the atmosphere change flavor in flight. That morphing proves that neutrinos have mass, though just a trace—less than a billionth as much as an electron. Were neutrinos massless, then according to Einstein's theory of relativity, they would have to travel at light speed. In that case, time would stand still for them and change would be impossible.

    For all their unruliness, "you're absolutely allowed to say that there is an emerging picture" of neutrinos, says André de Gouvêa, a theorist at Northwestern University in Evanston, Illinois. Their three flavors—electron, muon, and tau—blend into one another in "oscillations" that are described by just six parameters: the three differences in the masses, which determine the speeds of the oscillations, and three abstract mixing angles, which determine how much different flavors mix. In just the past 18 months that model has come in to much sharper focus.

    In March 2012, physicists with the Daya Bay Reactor Neutrino Experiment in China measured the last unknown mixing angle and found that it was bigger than many had assumed. All three mixing angles are now known to be bigger than zero, and that result implies that neutrinos and antineutrinos could oscillate differently—an asymmetry called CP violation that could help explain how the universe generated so much more matter than antimatter. The Daya Bay result in particular suggests that CP violation could be relatively easy to spot—if it's there—says Robert Plunkett of Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois: "Things that were thought to be very difficult are within striking distance."

    The emerging model grew even crisper this March, when cosmologists with the European Space Agency's Planck spacecraft released their study of the cosmic microwave background. The analysis probes the number of neutrino flavors and casts doubt on previous hints that a fourth, "sterile" neutrino might exist. "The vanilla cosmology with three neutrinos works great," de Gouvêa says. "That's sad but true."

    Physicists plan to put their understanding to the acid test in ever larger experiments that shoot neutrinos hundreds of kilometers through Earth, allowing them to change flavors along the way. In the United States, the proposed Long-Baseline Neutrino Experiment would fire neutrinos 1300 kilometers from Fermilab to a detector in an abandoned mine in South Dakota. In Japan, the planned Hyper-Kamiokande Experiment would shoot neutrinos 295 kilometers to a detector 20 times the size of Super-Kamiokande.

    Physicists hope that by taking enough different kinds of measurements, they may uncover discrepancies that challenge their current neutrino model. "If we try measuring neutrino mixing in many different ways, will surprises emerge?" asks Mary Bishai, a physicist at Brookhaven National Laboratory in Upton, New York. "Will the three-flavor model start to break down?"

    Physicists would also like to know how neutrinos get their mass in the first place. Like other particles in the standard model, they could acquire it from interactions with the Higgs field. Or, more tantalizingly, they might get their mass through a so-called seesaw mechanism, which would relate the neutrino's tiny mass to physics at an energy scale far higher than any particle accelerator could ever reach. But for this to happen, the neutrino must have one odd property: It must be its own antiparticle.

    To find out if it is, physicists are using underground detectors to look for a new type of nuclear decay called neutrinoless double beta decay, which can occur only if the neutrino is its own antiparticle. So far, no clear sightings have turned up. In July, the GERDA experiment in Italy's subterranean Gran Sasso National Laboratory showed that a previously claimed observation in the isotope germanium-76 was spurious. If the decay exists, many researchers suspect it will take far bigger detectors, weighing a tonne or more, to spot it. Or it could be immeasurably small.

    Still, neutrino physics is the one place researchers have peeked beyond the standard model, giving these elusive particles a powerful allure.

  6. North Korea

    Sizing Up a Slumbering Giant

    1. Richard Stone

    A thousand years ago, Mount Paektu unleashed one of the biggest eruptions in recent history. An unusual collaboration aims to learn why the volcano is so potent.

    On the prowl.

    Researchers on last month's expedition searched for rocks that could shed light on past eruptions.


    People in the hamlet of Sin Mu Song in northwestern North Korea had never laid eyes on a Westerner before James Hammond set to work in a nearby potato field last month. With North Korean colleagues, the seismologist from Imperial College London installed a broadband seismometer in an underground concrete shelter. Afterward, he sampled the local tobacco, rolled in a piece of Korean newspaper. "It was really smooth," he says, like "a pretty nice cigar."

    Hammond had reason to celebrate. He and two U.K.-based colleagues had just completed the first season of a trailblazing project to assess the eruption history, underlying structure, and potential for future unrest at Mount Paektu, a volcano straddling the border between the Democratic People's Republic of Korea (DPRK) and China. "We felt very privileged," says Clive Oppenheimer, a volcanologist at the University of Cambridge in the United Kingdom.


    Geologist Kim Ju Song (foreground) and a colleague examine Millennium Eruption deposits on Paektu's eastern flank.


    Paektu is quiet now, but it has a fearsome past. In the middle of the 10th century C.E., the volcano, called Changbai in China, uncorked the Millennium Eruption, one of the largest of the past 10,000 years. A decade ago, swarms of small tremors at the volcano set Chinese and Korean authorities on edge, prompting both nations to step up monitoring. The geological spasms subsided, but concerns that Paektu may be poised to blow again have opened the door to one of the first substantive scientific collaborations between DPRK and the West.

    Getting the remarkable enterprise off the ground wasn't easy. It took 2 years to win permissions from the U.K. and U.S. governments to ship crucial instruments to North Korea and the last-minute intervention of the United Kingdom's Royal Society to sign agreements with DPRK organizations that allowed fieldwork to proceed. But as Martyn Poliakoff, foreign secretary of the Royal Society, puts it, "We felt it was something that is well worth doing."

    A scarred land

    The week of fieldwork "really was spectacular," says Hammond, who installed six broadband seismometers on a line running east from the volcano. The instruments will listen for any stirring beneath Paektu. They will also register seismic waves from across the globe as they ripple through Paektu's plumbing, allowing Hammond and company to image its magma chamber and surrounding rock.

    While Hammond set to work, Oppenheimer and his graduate student, Kayla Iacovino, a U.S. citizen, collected samples, mostly pumice, that should reveal new details about the sequence of events during the Millennium Eruption and recent, smaller eruptions.

    The scars from the ancient explosion are still visible. The blast heaped ash and pumice on 33,000 square kilometers of northeast China and Korea, charring and entombing a thick forest and creating a barren landscape that to this day is largely treeless. Gargantuan pyroclastic flows—avalanches of superheated gas and debris—seared whole valleys and lined their walls with otherworldly ignimbrite rock tubes. In recent history, only the 1815 Tambora eruption in Indonesia—responsible for the "year without a summer"—has rivaled it.

    Paektu's ferocity is an enigma. It lies hundreds of kilometers west of the Ring of Fire, where colliding tectonic plates along the edge of the Pacific Basin fuel many of the world's most powerful volcanoes. One possible explanation for its potency is water squeezed from minerals in the subducting Pacific Plate, 600 kilometers below the volcano. Adding water to hot mantle rock can cause it to melt, creating a magma supply.

    But the chemistry of Paektu's pumice and other data cast doubt on that explanation, says James Gill, a volcanologist at the University of California, Santa Cruz, who has conducted fieldwork on the Chinese side of the volcano since 1990.

    Gill sees signs that the volcano is instead stoked by a mantle plume—a deep-rooted conduit that carries magma from the lower mantle to the surface. Backing that idea are unpublished data from a seismic array in China showing a "hole" in the subduction slab under Paektu. But other mantle processes may also be at play, and research on the volcano's Chinese flanks has failed to settle the question.

    That's why Oppenheimer and Hammond seized an opportunity that arose 2 years ago (Science, 4 November 2011, p. 584). The Pyongyang International Information Center on New Technology and Economy, or PIINTEC, a nongovernment organization, had reached out to Oppenheimer, a specialist on volcanic gases and author of a popular textbook, proposing a collaborative project. He roped in Hammond, a comrade in arms from a volcanological project in the blazing hot outback of Eritrea.

    North Korea offered different challenges. The first was funding. Hammond got the big-ticket items for free: The U.K. Natural Environment Research Council's Geophysical Equipment Facility loaned the seismometers. The Korean Earthquake Bureau (KEB) in Pyongyang, which is operating the array, agreed to periodically download data onto hard disks and send them to the Environmental Education Media Project, a nonprofit organization in Beijing that serves as a liaison between North Korea and the West. It will forward the data to Hammond.

    To house the seismometers, KEB staff members in recent months erected concrete huts at three of their field stations, including one beside the picturesque caldera lake, Lake Chon. Farther out from Paektu, KEB built bunkers for instruments in three villages, including one in the potato field at Sin Mu Song, where residents have promised to keep an eye on the equipment to deter vandals.

    Funding for station construction, maintenance, and logistics came from the Richard Lounsbery Foundation in Washington, D.C., via a grant to AAAS, Science's publisher. Both organizations are assiduously reaching out to scientists in nations having difficult relations with the United States. The project is off to a great start, says Norman Neureiter, senior adviser to AAAS's Center for Science Diplomacy. "Cooperation based on a real desire to get the job done has been excellent on both sides," he says.

    U.N. and U.S. export controls and sanctions on North Korea posed a tougher challenge. They prohibit a long list of instruments and devices, including ones as simple as thumb drives and cameras, from being shipped or carried into the country, even for temporary, personal use. AAAS spent months working with the U.S. State Department and the Commerce Department to land an export license for the project. The U.K. government's review of a separate license application took even longer, with approval coming just days before the seismometers had to be put on a plane for Pyongyang. "Everybody behaved sensibly and didn't get into a panic," Poliakoff says.

    Another challenge was fulf illing the North Koreans' desire for legal documents spelling out the research plan and each party's responsibilities. It was too complicated for KEB and PIINTEC to sign such a document with a U.S. organization, but the Royal Society came to the rescue.

    Delving deeper

    Once in North Korea, Oppenheimer and Iacovino spent several days collecting samples at favorite outcrops of senior KEB geologist Kim Ju Song and his colleagues in the bureau and the DPRK Academy of Sciences. A highlight was excavating at the base of a 10-meter-thick blanket of pumice from the Millennium Eruption. "It's always interesting to see what was on the ground immediately before a big eruption," Oppenheimer says. Pollen, for instance, can reveal the season that the ash fell. And deposits at the bottom of the heap show how the eruption began to unfold—information that could help researchers assess the hazards of a modern-day Millennium-scale eruption.

    Oppenheimer and Iacovino also plan to study volatiles trapped within crystals in the pumice, which can hold clues to the types and amounts of gases released. Such details could explain why the Millennium Eruption, unlike other eruptions on that scale, did not cool Earth's climate—a curious fact that volcanologist Xu Jiandong of the China Earthquake Administration in Beijing and his colleagues reported in January in Geophysical Research Letters.

    The black pumice at the top of the pile presents its own mystery: Was it deposited by pyroclastic flows during the Millennium Eruption, or by one of a handful of later blasts known from historical records? Characterizing these eruptions, including the most recent in 1903, can reveal how Paektu's plumbing has changed since the Millennium Eruption. Oppenheimer and Iacovino also took a motorboat out on Lake Chon to observe volcanic gases bubbling to the surface. They intend to return next summer to collect and analyze the gases, which could hold clues to the viscosity of the magma. More viscous magma would take higher pressure to eject, raising the odds of a more powerful eruption.

    In future expeditions, the team hopes to image the volcano's magma chambers with magnetotelluric sensors, which map subsurface variations in conductivity. They also hope to host Korean colleagues in the United Kingdom, for training in volcano monitoring and to collaborate on analyses of rock samples and data interpretation. Publications arising from the fieldwork will surely have DPRK co-authors, Oppenheimer says. Hammond envisions a more extensive seismometer array. But a full picture of the mountain's insides will also require data from stations across the border in China, Gill says—which means more science diplomacy.

    Still, by simply beating the odds and nurturing mutual respect, last month's expedition has revealed possibilities for scientific cooperation hitherto unimaginable—reason enough for the scientists and their backers to break out the cigars.