Mammals with pouches, like this red kangaroo, didn't originate in Australia, but they have prospered there like nowhere else on the planet. Why?

Photo credit: istockphoto.com/© Michelle Allen/WebStuff.biz Pty Ltd

Evolution Down Under

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<p>Australia, the smallest of the seven continents, is the world capital of two of the three types of mammal on Earth: the marsupials, like the kangaroo and koala, which nourish their young in pouches, and the monotremes, featuring the platypus and the echidnas, which nourish their young in eggs. (The third variety, placentals, include all the rest of us—from mice to whales to people—which nourish their young in an advanced placenta.)</p>
<p>How did this happen? Why did Australia get a preponderance of pouched and egg-laying mammals? And, at the same time, precious few of the kind of mammal that dominates every other land in the world?</p><p>The story is a long one—say, 100 million years or more—and for decades was missing key sections. Only in recent years have paleontologists succeeded in filling in some of those gaps to their satisfaction, enabling them to draw a reasonably detailed portrait of Australia's unique evolutionary history.</p><h3>Tooth Be Told</h3><p>Two long-standing questions were answered, remarkably enough, by a single fossil tooth. Or two single fossil teeth actually, unearthed on opposite sides of the globe, both in 1992.</p><p>Until sometime in the Cretaceous Period (146 to 65 million years ago), Australia, Antarctica, and South America all abutted one another in the southern supercontinent Gondwana. While they were attached, experts believe a single belt of forest likely stretched from southeastern Australia, through Antarctica, and into southern South America, and they know that early versions of all three mammal models existed at the time. Yet today no monotremes exist outside of Australia (and New Guinea), and no placental mammals that didn't fly or swim there—for example, bats or dugongs—exist in Australia except for rodents (which arrived only about five million years ago) and mammals that were introduced by people (who arrived by 60,000 years ago).</p><p>Why didn't monotremes use the connection to leave Australia? And why didn't placentals use it to enter Australia?</p><p>One of the teeth, uncovered in Argentina from deposits 63 to 61 million years old, answered the first question. Monotremes <i>had</i> lived elsewhere, for paleontologists determined that the tooth belonged to a platypus, an extinct species now known as the Patagonian platypus. (Which way the monotremes <i>originally</i> crossed the Antarctic bridge—from or to Australia—remains a mystery.) The second tooth, meanwhile, answered the second question. Placentals <i>had</i> come to Australia, for some experts believe the tooth, dug out of Queensland deposits radiometrically dated to at least 55 million years ago, belonged to a primitive, nonflying placental known as a condylarth. More recent discoveries hint that other early placentals lived in Australia, even before marsupials turn up in the fossil record.</p><p>But the monotremes in South America, and the placentals in Australia, didn't last.</p><p></p>
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<figcaption>The nature of Australia's solo northward journey once it parted from the remnants of Gondwana is a big part of the reason it is rife with pouched and egg-laying mammals. Here, the Three Sisters at Katoomba in New South Wales.
        
        <div class="credit">Photo credit: © Linda &amp; Colin McKie/istockphoto</div>
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<h3>Race Results</h3><p>Another nagging mystery involved the marsupials. While Australia is their capital, marsupials also occur in the Americas. South America, in particular, has a host of species, from the dwarf fat-tailed mouse opposum to the yapok, an aquatic marsupial. Paleontologists long wondered, When did the marsupials cross between Australia and the Americas, and which way did they go? That is, where did they originate?</p><p>The big animals Down Under walked an ecological tightrope.</p><p>It turns out the most "primitive" known marsupials come from early Cretaceous deposits in China (Sinodelphys genus), implying that the pouched mammals arose there. Recent studies suggest, however, that all or most of Australia's marsupials derive from an order of early North American marsupials of which today just a single representative exists, a sprightly, mouse-sized critter native to southern Chile known as the monito del monte, or "small monkey of the mountains." Paleontologists believe that the common ancestor that gave rise to the monito del monte, and the kangaroo and most or all other Australian marsupials, scurried from South America to Australia (through the intervening Antarctica) sometime before about 60 million years ago.</p>
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<figcaption>While Australia teems with marsupial species, North America north of Mexico has just one, the common opossum
        
        <div class="credit">Photo credit: istockphoto.com/© Rex Lisman: Wild Planet Photography</div>
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<p>The Australian mammalogist and paleontologist Tim Flannery likens the evolutionary history of the three mammal varieties in Australia and South America to a race. All three began the race in both places. Monotremes, which have the lowest metabolisms and energy needs of the three, thrived in Australia but lost the race in South America. Placentals, which have the highest metabolisms and energy needs of the three, thrived in South America but lost the race in Australia. Marsupials, whose metabolic rate and energy requirements lie between those of the other two, didn't lose on either continent but clearly prevailed in Australia.</p><p>Why? Focusing solely on Australia now, what accounts for its singular evolutionary path?</p>
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<h3>Dry Run</h3><p>The answer has everything to do with what happened to Australia after it broke away from Antarctica—its final tie to Gondwana—between about 45 and 38 million years ago. And what didn't happen to it.</p><p>First, what happened. After its severance, Australia began a long, slow drift north, which continues today. During its drift, the continent's climate changed repeatedly, from warm, wet "greenhouse" conditions to cold, dry "icehouse" conditions and back again. Between about 23 and 15 million years ago, the continent witnessed one of its lushest greenhouse phases, and marsupial diversity exploded, as did that of flamingoes and thunderbirds—giant, flightless herbivores that competed with the "elephants" and "rhinos" of the marsupial world, the big-bodied, wombat-like Diprotodon species. After 15 million years ago, rainfall and temperatures began to drop, a trend that has continued to the present day. Over this time, Australia dried out significantly, transforming the continent's great northern and central forests into semi-arid grasslands.</p>
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<figcaption>A lack of geologic upheaval over recent eons has left Australia with very poor soil, such as this distinctively ocher-colored earth near Uluru.
        
        <div class="credit">Photo credit: istockphoto.com/© Matej Pribelsky</div>
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<p>Now for what didn't happen. During its drift north over those roughly 40 million years, Australia eased into tropical waters even as the globe began a general cooling. One result was that the climate in Australia, notwithstanding those flips between greenhouse and icehouse, remained relatively stable during those 40 million years. Antarctica, meanwhile, traveled south and froze solid, and North America and Europe suffered repeated ice ages.</p><p>In fact, during its drift Australia kept just north of latitudes where glaciers form, so it was never glaciated in a substantial way. On top of that, over the past 60 million years the continent has enjoyed a degree of geologic restfulness not experienced by any other continent. Without glaciers, active volcanoes, and earthquakes stirring everything up, Australia's soils didn't get renewed, leaving it with the poorest-quality earth of any of the large landmasses.</p><h3>Walking A Tightrope</h3><p>All these things that happened and didn't happen, particularly in the past 15 million years, had a significant effect on Australia's wildlife. Because of their lower resting metabolic rate, marsupials could survive using less energy than similar-sized placental mammals, and they flourished. (Other creatures, including the thunderbirds and flamingoes, suffered extinctions as their lakes dried up and the luxuriant vegetation in the continent's midriff became grasslands.) Eventually the survivors began to grow in size, probably because larger-bodied animals were able to eat more of the progressively lower-quality vegetation. By the time humans arrived around 60,000 years ago, an impressive suite of megafauna roamed the landscape.</p>
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<figcaption>Paleontologists preserve a half-million-year-old specimen of Australia's feline-like carnivore, Thylacoleo, shortly after its discovery in an Australian cave in 2002.
        
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<p>Even as marsupials succeeded in Australia, however, they faced restrictions forced on them by the harsh environment. One concerned size. Despite their name, the megafauna in Australia never boasted any extremely large members. The biggest marsupial that ever lived, a Diprotodon, weighed about 4,400 pounds, or only about a third as much as an elephant. The largest kangaroo, now extinct, may have reached 440 pounds; the largest antelope, its closest counterpart in Africa, can weigh 2,200 pounds or more.</p><p>All told, one-quarter of all native Australian mammals have disappeared since Homo sapiens first came ashore.</p><p>Another restriction was in the diversity of top-level carnivores. Australia had only one cat-like meat-eater, Thylacoleo, the marsupial lion, and one dog-like meat-eater, Thylacine, the Tasmanian tiger. There was also a carnivorous kangaroo. Three top-order mammalian carnivores out of 60 or so large mammal species before humans turned up is paltry compared to the number on all other continents (save the usual exclusion, Antarctica). The paucity of mammalian meat-eaters left room for the rise of reptilian carnivores, including land crocodiles and the Komodo dragon-like giant goannas—all of which eventually disappeared.</p><p>Indeed, if the extinct megafauna shared one characteristic, it was vulnerability. Ultimately because of the poor soils, animals evolved low rates of reproduction and the ability not only to live on nutrient-poor flora but to opportunistically exploit the good times and withstand the bad. Australia is the only continent whose climate is largely dictated by the El Niño phenomenon, a non-annual event, and scientists see no reason why this wasn't the case when the megafauna were alive. The big animals Down Under, in short, walked an ecological tightrope.</p>
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<figcaption>Australia's extant marsupials and monotremes, represented here by a kangaroo and an echidna, squeaked past the last multi-species extinction. If it comes to it, can they do so again?
        
        <div class="credit">Photo credit: © Reuters/CORBIS</div>
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<h3>Gone and Here</h3><p>Sadly, they fell off that tightrope not long after the initial arrival of the smartest placental ever to walk the Earth—us. Sometime between 50,000 and 45,000 years ago, most megafaunal species, whether carnivore or herbivore, went extinct. The giant rat kangaroo, the thunderbirds, the giant goannas—all gone. These animals had ridden the Australian ark successfully through millions of years of natural change, but the change brought about by people was more than they could handle, and they succumbed. All told, one-quarter of all native Australian mammals, for one, have disappeared since Homo sapiens first came ashore on the continent.</p><p>Fortunately, some megafaunal species survived, including the largest living marsupial, the red kangaroo, and Australia remains marsupial and monotreme central. The trick now is to figure out how to ensure that those that pulled through the last mass extinction—wombats and bandicoots, dingos and emus—pull through the current one we humans have triggered worldwide.</p>
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<p data-block-key="usyp6">How did Australia come to be marsupial heaven?</p>

One Night in an E.R.

Join a Friday-night shift behind the swinging doors at Massachusetts General Hospital.

While Hippocrates, the so-called father of medicine, lived in the early 5th century B.C., the famous oath that bears his name emerged a century later. No one knows who first penned it.

The Hippocratic Oath Today

<p></p><h3>The Oath: Meaningless Relic or Invaluable Moral Guide?</h3><p>The Hippocratic Oath is one of the oldest binding documents in history. Written in antiquity, its principles are held sacred by doctors to this day: treat the sick to the best of one's ability, preserve patient privacy, teach the secrets of medicine to the next generation, and so on. "The Oath of Hippocrates," holds the American Medical Association's Code of Medical Ethics (1996 edition), "has remained in Western civilization as an expression of ideal conduct for the physician." Today, most graduating medical-school students swear to some form of the oath, usually a modernized version. Indeed, oath-taking in recent decades has risen to near uniformity, with just 24 percent of U.S. medical schools administering the oath in 1928 to nearly 100 percent today.</p>
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<p>Yet paradoxically, even as the modern oath's use has burgeoned, its content has tacked away from the classical oath's basic tenets. According to a 1993* survey of 150 U.S. and Canadian medical schools, for example, only 14 percent of modern oaths prohibit euthanasia, 11 percent hold convenant with a deity, 8 percent foreswear abortion, and a mere 3 percent forbid sexual contact with patients—all maxims held sacred in the classical version. The original calls for free tuition for medical students and for doctors never to "use the knife" (that is, conduct surgical procedures)—both obviously out of step with modern-day practice. Perhaps most telling, while the classical oath calls for "the opposite" of pleasure and fame for those who transgress the oath, fewer than half of oaths taken today insist the taker be held accountable for keeping the pledge.</p><p>Indeed, a growing number of physicians have come to feel that the Hippocratic Oath is inadequate to address the realities of a medical world that has witnessed huge scientific, economic, political, and social changes, a world of legalized abortion, physician-assisted suicide, and pestilences unheard of in Hippocrates' time. Some doctors have begun asking pointed questions regarding the oath's relevance: In an environment of increasing medical specialization, should physicians of such different stripes swear to a single oath? With governments and health-care organizations demanding patient information as never before, how can a doctor maintain a patient's privacy? Are physicians morally obligated to treat patients with such lethal new diseases as AIDS or the Ebola virus?</p>
<p>Other physicians are taking broader aim. Some claim that the principles enshrined in the oath never constituted a shared core of moral values, that the oath's pagan origins and moral cast make it antithetical to beliefs held by Christians, Jews, and Muslims. Others note that the classical Oath makes no mention of such contemporary issues as the ethics of experimentation, team care, or a doctor's societal or legal responsibilities. (Most modern oaths, in fact, are penalty-free, with no threat to potential transgressors of loss of practice or even of face.)</p>
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<p>With all this in mind, some doctors see oath-taking as little more than a pro-forma ritual with little value beyond that of upholding tradition. "The original oath is redolent of a convenant, a solemn and binding treaty," writes Dr. David Graham in JAMA, the Journal of the American Medical Association (12/13/00). "By contrast, many modern oaths have a bland, generalized air of 'best wishes' about them, being near-meaningless formalities devoid of any influence on how medicine is truly practiced." Some physicians claim what they call the "Hypocritic Oath" should be radically modified or abandoned altogether.</p><p>Below, see <a href="#classical">classical</a> and <a href="#modern">modern</a> versions of the oath. </p><p>*Orr, R. D., N. Pang, E. D. Pellegrino, and M. Siegler. 1997. "Use of the Hippocratic Oath: A Review of Twentieth-Century Practice and a Content Analysis of Oaths Administered in Medical Schools in the U.S. and Canada in 1993." The Journal of Clinical Ethics 8 (Winter): 377-388.</p><h3>Hippocratic Oath: Classical Version</h3><p>I swear by Apollo Physician and Asclepius and Hygieia and Panaceia and all the gods and goddesses, making them my witnesses, that I will fulfill according to my ability and judgment this oath and this covenant:</p><p>To hold him who has taught me this art as equal to my parents and to live my life in partnership with him, and if he is in need of money to give him a share of mine, and to regard his offspring as equal to my brothers in male lineage and to teach them this art—if they desire to learn it—without fee and covenant; to give a share of precepts and oral instruction and all the other learning to my sons and to the sons of him who has instructed me and to pupils who have signed the covenant and have taken an oath according to the medical law, but no one else.</p><p>I will apply dietetic measures for the benefit of the sick according to my ability and judgment; I will keep them from harm and injustice.</p><p>I will neither give a deadly drug to anybody who asked for it, nor will I make a suggestion to this effect. Similarly I will not give to a woman an abortive remedy. In purity and holiness I will guard my life and my art.</p><p>I will not use the knife, not even on sufferers from stone, but will withdraw in favor of such men as are engaged in this work.</p><p>Whatever houses I may visit, I will come for the benefit of the sick, remaining free of all intentional injustice, of all mischief and in particular of sexual relations with both female and male persons, be they free or slaves.</p><p>What I may see or hear in the course of the treatment or even outside of the treatment in regard to the life of men, which on no account one must spread abroad, I will keep to myself, holding such things shameful to be spoken about.</p><p>If I fulfill this oath and do not violate it, may it be granted to me to enjoy life and art, being honored with fame among all men for all time to come; if I transgress it and swear falsely, may the opposite of all this be my lot.</p><p>—Translation from the Greek by Ludwig Edelstein. From The Hippocratic Oath: Text, Translation, and Interpretation, by Ludwig Edelstein. Baltimore: Johns Hopkins Press, 1943.</p><h3>Hippocratic Oath: Modern Version</h3><p>I swear to fulfill, to the best of my ability and judgment, this covenant:</p><p>I will respect the hard-won scientific gains of those physicians in whose steps I walk, and gladly share such knowledge as is mine with those who are to follow.</p><p>I will apply, for the benefit of the sick, all measures [that] are required, avoiding those twin traps of overtreatment and therapeutic nihilism.</p><p>I will remember that there is art to medicine as well as science, and that warmth, sympathy, and understanding may outweigh the surgeon's knife or the chemist's drug.</p><p>I will not be ashamed to say "I know not," nor will I fail to call in my colleagues when the skills of another are needed for a patient's recovery.</p><p>I will respect the privacy of my patients, for their problems are not disclosed to me that the world may know. Most especially must I tread with care in matters of life and death. If it is given me to save a life, all thanks. But it may also be within my power to take a life; this awesome responsibility must be faced with great humbleness and awareness of my own frailty. Above all, I must not play at God.</p><p>I will remember that I do not treat a fever chart, a cancerous growth, but a sick human being, whose illness may affect the person's family and economic stability. My responsibility includes these related problems, if I am to care adequately for the sick.</p><p>I will prevent disease whenever I can, for prevention is preferable to cure.</p><p>I will remember that I remain a member of society, with special obligations to all my fellow human beings, those sound of mind and body as well as the infirm.</p><p>If I do not violate this oath, may I enjoy life and art, respected while I live and remembered with affection thereafter. May I always act so as to preserve the finest traditions of my calling and may I long experience the joy of healing those who seek my help.</p><p>—Written in 1964 by Louis Lasagna, Academic Dean of the School of Medicine at Tufts University, and used in many medical schools today.</p>
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<p>Read classical and modern versions of the oath and a short article about its controversial nature today.</p>

A replica of the six-inch reflecting telescope that Newton presented to the Royal Society in 1671

Newton's Legacy

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<p>Sir Isaac Newton's accomplishments border on the uncanny, as does his image in the world of science. As the historian Mordechai Feingold has written, "With time, the historical Newton receded into the background, overshadowed by the very legacy he helped create. Newton thus metamorphosed into science personified." So what is that legacy? What were those accomplishments? Here, familiarize yourself with Newton's greatest contributions.</p>
<h3>Invented the reflecting telescope</h3><p>The standard telescope of Newton's time, the refracting telescope, was not ideal. Its glass lenses focused the different colors inherent in light at different distances. This resulted, at the edges of any bright objects seen through the telescope, in colored fringes that rendered those objects slightly out of focus. Newton solved the "chromatic aberration" problem by using mirrors instead of lenses. His original reflecting telescope, which he built himself in 1668, was just six inches long. This modest device not only eliminated the colored fringes but magnified whatever it focused on by 40 times, which, as Newton noted at the time, "is more than any 6 foote Tube can do." After presenting his scope to the Royal Society, the then-unknown Newton was proposed for membership; he later served as its president for 24 years, until his death in 1727.</p><p></p>
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<figcaption>"Newton Investigating Light," from <cite>The Illustrated London News</cite>, June 4, 1870
        
        <div class="credit">© Jim Sugar/CORBIS</div>
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<p></p><h3>Proposed new theory of light and color</h3><p>Not long after he donated his telescope to the Royal Society, Newton delivered a paper to that august body about his novel theory of light and colors. Using prisms and his usual very exacting experimental technique, Newton had discovered that sunlight is comprised of all the colors of the rainbow, which could not only be separated but recombined into white light. "[T]he most surprising and wonderful composition was that of Whiteness," he wrote. "I have often with Admiration beheld that all the Colours of the Prisme being made to converge, and thereby to be again mixed ... reproduced light, intirely [sic] and perfectly white." Though he made his experiments on light as early as 1666, when he was only 24 years old, he didn't publish his classic Opticks, which summarized his findings on light and color, until 1704.</p><p></p>
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<figcaption><p>The first page of Newton's "How to Draw Tangents to Mechanicall Lines" (November 8, 1665), from his "Waste Book" manuscript. Image Credit: Library of Congress</p>
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<p></p><h3>Discovered calculus</h3><p>When Newton began to muse on the problem of the motion of the planets and what kept them in their orbits around the sun, he realized that the mathematics of the day weren't sufficient to the task. Properties such as direction and speed, by their very nature, were in a continuous state of flux, constantly changing with time and exhibiting varying rates of change. So he invented a new branch of mathematics, which he called the fluxions (later known as calculus). Calculus allowed him to draw tangents to curves, determine the lengths of curves, and solve other problems that classical geometry could not help him solve. Interestingly, Newton's masterwork, the Principia, doesn't include the calculus in the form that he'd invented years before, simply because he hadn't yet published anything about it. But he did combine related methods with a very high level of classical geometry, making no attempt to simplify it for his readers. The reason was, he said, "to avoid being baited by little Smatterers in Mathematicks."</p><p></p>
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<figcaption><p>Newton's first and second laws of motion, in Latin, as they appear in the original 1687 edition of the <i>Principia</i>. Image Credit: Cambridge University Library</p>
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<p></p><h3>Developed three laws of motion</h3><p>Newton's Principia is difficult to comprehend on two levels, even for experts: in its original form, it is written in Latin, and it uses very challenging mathematics. Yet one thing that comes out very simply and very clearly to all is his three laws of motion:</p><ol><li><i>Law of inertia:</i> Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed upon it.</li><li><i>Law of acceleration:</i> Force is equal to the change in momentum (mV) per change in time. For a constant mass, force equals mass times acceleration, <i>F = ma</i>.</li><li><i>Law of action and reaction:</i> For every action, there is an equal and opposite reaction.</li></ol><p>To these Newton added, in the Principia, two general principles of space and time, many careful explanations, and much else besides. All of this went into his classic explanation of how the universe works, otherwise known as Newtonian mechanics. (Mechanics developed into a branch of physical science that deals with energy and forces and their effect on bodies.)</p><p></p>
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<figcaption>As an old man Newton claimed the idea of universal gravitation came to him while watching an apple fall in the garden of his mother's house at Woolsthorpe (seen here as it appears today).
        
        <div class="credit">© Bettmann/CORBIS</div>
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<h3>Devised law of universal gravitation</h3><p>Newton said shortly before his death that it was seeing an apple fall in his mother's garden that set him thinking "that the power of gravity ... was not limited to a certain distance from the earth but that this power must extend much farther than was usually thought. Why not as high as the moon ... and if so that must influence her motion and perhaps retain her in her orbit." This brainstorm (which some scholars suspect Newton may have invented late in life) ultimately led to his law of universal gravitation. The law says that all particles of matter in the universe attract every other particle, that gravitational attraction is a property of all matter. The law explained many things, from the orbits of the planets around the sun to the influence of the moon and sun on the tides. And it held sway as the accepted description of terrestrial and celestial mechanics for almost 200 years—until Einstein came along and rocked the boat with relativity.</p><p></p>
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<figcaption>The work of alchemists, depicted here in a painting by the 19th-century artist William Fettes Douglas, helped lay the groundwork for modern chemistry.
        
        <div class="credit">Courtesy Wikipedia.org</div>
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<p></p><h3>Advanced early modern chemistry</h3><p>Newton spent untold hours of his life practicing alchemy. Like other alchemists, he sought to turn base metals into gold, find a universal cure for disease, and secure the elixir of life, which promised perpetual youth and eternal life. In his garden shed outside his rooms at Trinity College, Cambridge, in the midst of phials and furnaces, mortars and pestles, Newton pored over ancient texts and performed endless experiments. Yet while he never found what he and other alchemists sought, and while he only published one short paper that grew out of his alchemical experiments (a two-page speculation on acids), his work was not for naught. As the historian Jed Buchwald has said, "As historians have shown in the last several decades, there was a much more profound element to the practice of alchemy which really makes it deserving of being called early modern chemistry." Through his meticulous efforts, Newton greatly furthered the practice and techniques of chemical science.</p><p></p>
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<figcaption>"Newton," painted by William Blake in 1795
        
        <div class="credit">Erich Lessing/Art Resource, NY</div>
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<p></p><h3>Became father of modern science</h3><p>Newton essentially invented many elements of the modern scientific method. His paper on the properties of light that he presented to the Royal Society in the early 1670s shows all the hallmarks of the method he would use throughout his long life: conducting experiments and taking very careful notes on the results; making measurements; conducting further experiments that grew out of the initial ones; formulating a theory, then creating yet further experiments to test it; and finally, painstakingly describing the entire process so that other scientists could replicate every step of the way. This method governs how all science is conducted today. Newton once famously said, "If I have seen further it is by standing on the shoulders of Giants." Many scientists today would argue that the greatest Giant of all in the world of science was Isaac Newton himself.</p>
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<p data-block-key="dn70m">Gravity. Laws of motion. Reflecting telescope. Calculus. The list of Sir Isaac&#x27;s accomplishments goes on...</p>

Forecasting Volcanic Eruptions

<p>
	The answer, perhaps not surprisingly, is complicated. In fact, Miller and Rose are not as far apart on this issue as they might sound. John Eichelberger, a volcanologist at the University of Alaska Fairbanks, may have summed up the situation best when I asked him if the field was well on its way to becoming an exact science or was still in its infancy. He chuckled and said, "Well, when it works, it's well on its way. When we have a spectacular failure, it's in its infancy."</p>
<p>
<figure class="richtext-image full-width">
<img alt="Mt. Pinatubo" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/forecasting-volcanic-eruptions-01.width-990_xQ5XCaq.jpg"/>
<figcaption>Blowing hot and cold: Active volcanoes like Mt. Pinatubo, whose simmering crater is shown here just over a year after the major eruption of June 15, 1991, keep experts ever on their toes for possible unrest.
        
        <div class="credit">© Les Stone/CORBIS</div>
</figcaption>
</figure>
</p>
<h3>
	When it works, when it fails</h3>
<p>
	Both scenarios have occurred in recent years. Mt. Pinatubo in the Philippines is one of eruption forecasting's great success stories. When it awoke in the spring of 1991, volcanologists rushed in, installed monitoring equipment, and correctly identified the nature of the unrest. They rapidly completed a hazard assessment, based in part on looking at evidence from past eruptions there. And they provided good advice to public officials and the Philippine and U.S. militaries. Just days before the mountain exploded on June 15, the Filipino government successfully evacuated more than 60,000 people from towns and villages (and the U.S. Clark Air Base) that were later partly or wholly destroyed.</p>
<p>
	Tungurahua volcano in Ecuador, on the other hand, might fall in the "spectacular failure" category of eruption forecasting. (Like meteorologists, most volcanologists tellingly prefer the less precise term "forecasting" to "predicting.") When Tungurahua woke up in 1999, volcanologists from the USGS's Volcano Disaster Assistance Program (VDAP) quickly helped their Ecuadoran colleagues set up monitoring equipment to evaluate the hazards and track the volcano's restlessness. When a magmatic eruption began there, the team smelled trouble: Three well-documented eruptions within the past 300 years that had begun just that way had resulted in explosive eruptions that devastated the volcano's flanks and killed large numbers of people. Based on the 1999 team's urgent recommendation, the Ecuadoran authorities evacuated more than 15,000 people living beneath the volcano.</p>
<p>
	Five years later, Tungurahua, while gurgling on a daily basis, has yet to produce any major explosive eruptions. "It was an economic and political disaster, and a worse one is in the making, because those 15,000 people returned to their villages and have categorically refused to leave again," says Miller, who directs VDAP and led the 1999 team. Miller fears the mountain could still produce damaging eruptions.</p>
<p>
	Why the disparity in results between Pinatubo and Tungurahua? The reason is that when a volcano shows signs of disquiet, even one that is thoroughly known and instrumented, volcanologists can still never be certain when it will erupt, in what way, and to what degree—or even if it will erupt at all.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/forecasting-volcanic-eruptions-02.width-990_E6vYA4L.jpg"/>
<figcaption>Ecuador's Tungurahua stands ominously close to settlements like Pelileo, pictured here in early 2000. When the mountain came alive in 1999-2000, officials evacuated the nearby town of Banos for three months.
        
        <div class="credit">© Albrecht G. Schaefer/CORBIS</div>
</figcaption>
</figure>
</p>
<h3>
	Reason for hope</h3>
<p>
	While that may not sound reassuring, the volcanological community has actually made great strides in eruption forecasting in recent years. Arguably the most significant strides have come in the development of new tools for detecting changes in a volcano's seismicity, ground deformation, and gases—the Big Three to watch at an active volcano.</p>
<p>
	Seismic networks have improved enormously. Broadband seismic sensors coupled with improved telemetry and computer systems now enable volcanologists, like never before, to receive, analyze, and display information about the earthquakes that typically precede eruptions. When it comes to gauging the slight swellings of ground surface that can signal an impending eruption, volcanologists today use satellite-based Synthetic Aperture Radar systems that can detect even the minutest elevation changes over an entire volcano, as well as ground-based GPS units that can communicate deformation data to volcano observatories in near real time.</p>
<blockquote>
	So can we forecast eruptions? The best answer, for now, seems to be "sometimes."</blockquote>
<p>
	As for monitoring gases, volcanologists two decades ago mostly measured releases of sulfur dioxide, which can give an indication of whether potentially explosive magma is approaching the surface. But now they can monitor a suite of gases, primarily sulfur dioxide, carbon dioxide, and hydrogen sulfide. Flying through a plume of gas rising from a volcano, volcanologists can very accurately calculate the flux of these three gases in terms of tons per day.</p>
<p>
	Researchers are even starting to reach within volcanoes themselves in hopes of getting a better idea of their plumbing. Eichelberger is part of an international team that in July 2004 managed to drill into the main magma conduit that feeds Unzen, a dangerously active volcano in Japan. (An eruption there in 1792 killed more than 15,000 people—see <a href="/wgbh/nova/volcanocity/deadly.html">Deadly Volcanoes</a>.) The conduit's now-solidified contents, samples of which the team has collected, hold valuable clues to the magma's composition, temperature, and pressure as it rose to the surface during Unzen's last eruption, which lasted for four years in the early 1990s.</p>
<p>
<figure class="richtext-image full-width">
<img alt="Unzen volcano" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/forecasting-volcanic-eruptions-03.width-990_vbfEoKn.jpg"/>
<figcaption>Mudflows from Unzen volcano took out most of the ground floor of this house in Shimabara, Japan. In this photo from March 1992, Unzen continues to erupt in the background.
        
        <div class="credit">© Roger Ressmeyer/CORBIS</div>
</figcaption>
</figure>
</p>
<h3>
	Hurdles</h3>
<p>
	Despite these advances, many obstacles remain to successful forecasting. For starters, it takes a long time to gain a good understanding of even a single volcano's behavior. The more former eruptions to study the better, but if a volcano only erupts on average every several hundred years, that understanding can be elusive.</p>
<p>
	For some major eruptions, volcanologists have had virtually nothing to work from. The 1912 explosion of Novarupta volcano in Alaska was the most dramatic volcanic event of the 20th century, packing 10 times the force of Mt. St. Helens's May 18, 1980 eruption. But the magnitude of the cataclysm came as a complete surprise. "I doubt even today if we would guess the scale of it, because nothing like that had happened there for millions of years," says Eichelberger, who doubles as Coordinating Scientist for the Alaska Volcano Observatory. "You don't guess complete changes in behavior like that."</p>
<p>
	Moreover, every volcano has a unique plumbing system, and each has its own supply rate of magma from sources deep underground. That means generalizing from one to the next can be tricky. "In other words, what we've learned about Mt. St. Helens does not tell us much about Mt. Shasta or Mt. Hood," says Miller, who is based in the Cascade Mountains of the Pacific Northwest. Even for the best known and best instrumented volcanoes in the world, volcanologists can never be certain how they will behave when they come alive. Despite numerous well-studied eruptions at Mt. St. Helens since the 1980 catastrophe, for instance, experts were unable to say during its awakening in 2004 whether its eruptions would be effusive or explosive—that is, a burp or a blast.</p>
<p>
<figure class="richtext-image full-width">
<img alt="mt st helens" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/forecasting-volcanic-eruptions-04.width-990_Lz7dcHJ.jpg"/>
<figcaption>After its monster cataclysm of May 18, 1980, Mt. St. Helens continued to erupt periodically for several months. Here, an eruption plume from July 22 of that year dwarfs both St. Helens and Mt. Rainier in the distance.
        
        <div class="credit">Courtesy of USGS</div>
</figcaption>
</figure>
</p>
<p>
	Other obstacles to forecasting are financial. "The problem is, there are 900 potentially active volcanoes in the world, and only about a tenth of them are instrumented enough to provide forecast capability," Bill Rose says. "We have the technology to do it, but the cost is too high to instrument the whole world." Many threatening volcanoes in Central and South America, Africa, and the southwest Pacific have little or no scientific scrutiny. Cerro Quemado in Guatemala, for example, has tens of thousands of people living around it, yet Miller says he's not aware of any monitoring on that peak, not even a single seismometer. Even the USGS has limited funding for researchers eager to plumb scientific questions about possibly dangerous volcanoes in the U.S. "Basically we're doing the best that we can with the budget we have, using the tools that give us the biggest bang for the buck," Miller says.</p>
<p>
	So can we forecast eruptions? The best answer, for now, seems to be "sometimes."</p>

How good are we at predicting when an active volcano will next blow its top?

Wave of the Future

<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-01.width-990_3di5Sft.jpg"/>
<figcaption>If only people along Indian Ocean coasts had known to flee when the sea retreated on December 26, 2004, thousands of lives might have been saved. Here, fishermen in Sri Lanka collect washed-up fish five days after the tsunami.
        
        <div class="credit">© Joseph Khakshouri/Corbis</div>
</figcaption>
</figure>
</p>
<p>
	No one knew, because nothing like that had happened in living memory. The last widely devastating tsunami in the Indian Ocean was that spawned by the eruption of Krakatoa in 1883, which killed 36,000 people. Disaster officials in the region understandably have focused on cyclones, floods, and other natural calamities that strike the region every year.</p>
<p>
	Now, in the wake of one of the worst natural disasters in recorded history, their focus has broadened. Within days of the catastrophe, with the adage "better late than never" sitting heavily on everyone's minds, commentators worldwide were calling for a tsunami warning system in the Indian Ocean akin to a successful one now operating in the Pacific. If such a system had been up and running in the Indian Ocean, experts agree that many of the thousands of lives lost in places relatively distant from the quake's epicenter, such as Thailand, Sri Lanka, and India, might have been saved.</p>
<p>
	But setting up a truly effective warning system, one that can alert coastlines even as close to a tsunami's birthplace as northwest Sumatra was last December, is a daunting task. In talking to a host of experts on tsunami detection and hazard mitigation, it's clear that numerous challenges exist to ensuring that disaster officials are well-prepared for the next big tsunami—which, incidentally, could arise at any time off the coast of the U.S. as close as it was off Sumatra.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-02.width-990_OXtVPtL.jpg"/>
<figcaption>The world's first tsunami warning system was created two years after enormous waves triggered by a 1946 earthquake in Alaska crashed ashore thousands of miles away in Hawaii.
        
        <div class="credit">Courtesy Pacific Tsunami Museum archives/Aleta V. Smith Collection</div>
</figcaption>
</figure>
</p>
<h3>
	Towards a warning bell</h3>
<p>
	Before installing a warning system, experts need to identify and map areas of risk. Much of this preliminary work has been done in the Indian Ocean; some needs more effort. The work includes pinpointing tectonic faults of concern, mapping the seafloor topography, studying the effects of past tsunamis, and making computer models showing how future tsunamis might behave.</p>
<p>
	"Computer models are the brain of any warning system," says Tad Murty, a tsunami expert at the University of Manitoba at Winnipeg who recently spent two months in his native India working with Indian counterparts. "We will run a series of scenarios, all permutations and combinations of anything that can happen, so that when an earthquake occurs, the computer will match the closest scenario and then use it to help with warning."</p>
<p>
	Murty estimates an Indian Ocean warning system will cost between $250 and $400 million. That will represent the combined expenditure for all 37 or so countries that have coastline on the Indian Ocean. While the Indian system will have major differences from its Pacific counterpart in its computer models, he says, it will likely be similar to the Pacific setup in instrumentation.</p>
<p>
	The Pacific system was established two years after a 1946 quake off Alaska spawned a tsunami that killed over 100 people and caused massive destruction around the Pacific. Initially the system was based on seismic data plus inputs from a series of tide gauges that sent information about water levels around the ocean to warning centers in Hawaii, Japan, and elsewhere in the Pacific. Experts used the system to accurately "call" every major tsunami in the years since, but wishing to err on the side of conservatism, they also had a false-alarm rate until relatively recently of 75 percent.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-03.width-990_Xqsor6p.jpg"/>
<figcaption>The six buoys in the new Pacific tsunami warning system were deployed in 2002.
        
        <div class="credit">© NOAA/PMEL</div>
</figcaption>
</figure>
</p>
<p>
	Then, in 2002, new sensors went into place to supplement the tide gauges. Six monitoring devices anchored to the seafloor far out in the Pacific measure changes in water pressure above. When such changes indicate a tsunami passing overhead, a sensor sends a signal with data to a buoy directly above, which forwards the message via satellite to the Pacific Tsunami Warning Center (PTWC) in Hawaii. Specialists then analyze the data, decide if a potentially dangerous tsunami is under way, and take appropriate action.</p>
<p>
	The new system has already proved its value. In 2003, experts were able to call off a warning after analysts determined that the tsunami generated by a big quake off Alaska was not hazardous. Within weeks of the Indian Ocean tsunami, President George W. Bush ordered that 32 additional such buoys be added to the Pacific as well as to the Atlantic and Caribbean (neither of which currently has a tsunami warning system, even though both have on occasion spawned deadly tsunamis).</p>
<p>
<figure class="richtext-image full-width">
<img alt="sign post" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-04.width-990_NgQpEZh.jpg"/>
<figcaption>A sign along Highway 100 in Fort Canby State Park, Washington
        
        <div class="credit">© Connie Ricca/Corbis</div>
</figcaption>
</figure>
</p>
<h3>
	Fine tuning</h3>
<p>
	The Pacific warning system is not perfect, however. For one thing, the seismic data currently tell quickly about a quake's epicenter, but not about the alignment of the rupture. If experts had known immediately that the Sumatran rupture had been along the north-south portion of the fault, they would have known that any resulting tsunami would have traveled largely east-west and could have predicted what targets lay in its path. "Right now, there's no quick way to know which way that rupture goes," says Chip McCreery, director of the PTWC. "We need to figure that out."</p>
<p>
	Perhaps more importantly, experts at the PTWC had no way of determining in short order how large the quake was. It took about two hours, based on calculations made at Harvard's Centroid-Moment Tensor Project, for PTWC officials to learn that it was a 9.0. (Some seismologists now believe the quake might have been a 9.3.) Every undersea quake of that magnitude has triggered a lethal tsunami, says Tom Heaton, a seismologist at the California Institute of Technology. "If these guys [at the PTWC] had known 10 minutes after the earthquake that they'd had a nine, I'll bet they'd have been on the phone to CNN worldwide saying 'Magnitude nine earthquake! There's an extreme emergency in the Indian Ocean!'"</p>
<blockquote>
	"If you feel an earthquake, if you see the water retreating, or if you hear a loud roar from the ocean, head inland fast."</blockquote>
<p>
	Heaton stresses that it was not the fault of the PTWC but rather what he believes is a certain lack of communication between the seismic and tsunami communities. But fixing this specific problem is straightforward, he believes: The capability exists for centers such as the PTWC to detect the size of earthquakes anywhere in the world within minutes after the event, at a cost of perhaps $100,000 and several months of work to upgrade software, he says.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-05.width-990_H3GVB3W.jpg"/>
<figcaption>At a tsunami relief center in Cuddalore on the Indian coast, a father and his son eat breakfast on December 31, 2004, five days after the tsunami.
        
        <div class="credit">© Arko Datta/Reuters/Corbis</div>
</figcaption>
</figure>
</p>
<p>
	Earthquakes smaller than 9.0 can also launch tsunamis, and for these analysts' skills are truly put to the test. All tsunamis are different, and determining their level of threat can be tricky. Analysts can be caught between a rock and a hard place. On the one hand, experts can't afford to be wrong—to fail to warn about a tsunami that ends up taking lives. On the other hand, evacuations are costly. In Hawaii, the price tag to stage an evacuation is over $50 million, says George Curtis, a tsunami expert at the University of Hawaii at Hilo. "You have a tremendous loss of business. You have a great expense of overtime for police, firemen, road crews putting up roadblocks. It's a major disruption." And if you have too many false alarms, a cry-wolf reaction occurs, and citizens grow complacent.</p>
<p>
	Even the finest warning system, with the best technology and personnel, will be useless without the means to communicate warnings to relevant authorities. Sadly, the 2004 tsunami showed up this lack all too well in the Indian Ocean. In Thailand, for example, seismologists knew early on how big the quake was and that it probably spawned a big tsunami. "But for an hour they didn't know what to do about it," says Curtis. "They didn't know who to call." In Hawaii and other parts of the Pacific system, such communication channels to civil defense authorities are in place and tested regularly.</p>
<h3>
	Learn and live</h3>
<p>
	The final piece of the puzzle is education. In potentially vulnerable parts of the Pacific region, from Japan to Hawaii to Alaska, vigorous public education programs have been in place for some time. One such hot zone is the coastline stretching from Washington, through Oregon, and into northern California. This strip would lie in the line of fire of any tsunami triggered by an eruption along the Cascadia subduction zone, which runs for nearly 700 miles along the Pacific Northwest coast. Any tsunami could hit nearby shores within 20 to 40 minutes.</p>
<p>
<figure class="richtext-image full-width">
<img alt="tugboat amidst buildings" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wave-of-the-future-06.width-990_JqqSv4I.jpg"/>
<figcaption>Since this article appeared in 2005, a tsunami on March 11, 2011 devastated the northeast coast of Japan (this tugboat was carried 1,600 feet inland). Japan's robust tsunami warning system worked as designed that day, but at magnitude 9.0, the earthquake and subsequent tsunami were much larger than experts had planned for.
        
        <div class="credit">Callum Macrae/© WGBH Educational Foundation</div>
</figcaption>
</figure>
</p>
<p>
	"The educational program they have in place there is that you should have a backpack filled with all the stuff you need to be self-sufficient for a couple of days," says Eddie Bernard, director of the Seattle-based Pacific Marine Environmental Laboratory, which developed the buoy-based warning system and is a leading center of tsunami research. "Once you feel the earthquake, you grab that backpack on your way out of your house." Both authorities and residents have been indoctrinated with where to go and what to do. (Knowing when it's safe to return after a local quake is something still needing research, Bernard says, but as a benchmark, in the 2004 event tsunami waves pummeled the Sumatran coast for 12 hours following just five minutes of shaking.)</p>
<blockquote>
	"Every step you go inland, even if it's not up, is a step toward more safety."</blockquote>
<p>
	Time can be the enemy of effective education, however. "Humans are amazingly adaptive animals, so those impacted will remember this horrific tsunami," says Bernard. "It's our responsibility to devise effective educational programs to ensure that the next generation does not forget." McCreery, for one, says it's vital to get tsunami hazards into school curricula. In devastated parts of the Indian Ocean, local authorities could also erect memorials to victims that double as warning signs. "The memorial could explain what the hazard is, that it's going to happen again, and what to do," he says.</p>
<p>
	Knowing oneself what to do, rather than waiting to hear from officials, can mean the difference between surviving and not. Even the most efficient detection-and-warning system might not be able to warn areas extremely close to subduction zones. The tsunami ravaged Sumatra's Banda Aceh only a half hour after the quake, and any tsunamis generated by quakes off the Aleutian islands could hit nearby Alaskan communities within 15 minutes. (The U.S. maintains a separate warning system in that state that can warn regional locations based on seismic data alone.)</p>
<p>
	For residents of such coasts, and really for anyone who ever visits a beach on vacation, it's essential to know nature's three tsunami warning signs, Bernard says. "If you feel an earthquake, if you see the water retreating, or if you hear a loud roar from the ocean, those are three natural indicators that a tsunami could be present. In any of those cases, head inland fast. Every step you go inland, even if it's not up, is a step toward more safety."</p>

What will it take to be ready for the next major tsunami?

Wireless Black Boxes

<p>
<figure class="richtext-image full-width">
<img alt="black box" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wireless-black-boxes-01.width-990_R2ymnBT.jpg"/>
<figcaption>Black boxes, which are actually vivid orange to make them easier to find after a crash, are built tough: Inside each is a crash-survivable memory unit that can withstand exceptional heat, pressure, and violence. But what if the box is lost?
        
        <div class="credit">© National Transportation Safety Board</div>
</figcaption>
</figure>
</p>
<p>
	The New York-to-Geneva flight had mysteriously plunged into the ocean off Nova Scotia on the night of September 2, 1998, killing all 229 people aboard. The black boxes could have provided valuable clues as to the cause of the crash. But without their data on the final minutes of the flight, the Transportation Safety Board of Canada undertook what became a four-and-a-half-year, $39 million investigation to try to determine the cause by other means.</p>
<p>
	Neither I nor anyone else in the room that day had an answer to my colleague's question. So I called experts at the Federal Aviation Administration (FAA) and National Transportation Safety Board (NTSB) as well as in the academic and private sectors. Their collective answer: They're working on it, with potential not just for black-box data transmission but also for better troubleshooting during emergencies, improved airline efficiency and maintenance, even telemedicine. But it's easier said than done.</p>
<h3>
	Instant info</h3>
<p>
	The advantages to having continuous, real-time transmission of flight and cockpit information are many. First, in the case of a crash, black-box data would be available to investigators immediately. They wouldn't have to wait for the recorders to be dug out of the ground or fished from the seafloor. This has important implications in our age of terrorism. Law-enforcement officials need to know quickly whether a crash was terrorist-related; suspect trails grow faint with each passing hour, much less the days or weeks it can take to recover black boxes and analyze their recordings.</p>
<p>
<figure class="richtext-image full-width">
<img alt="hangar in Nova Scotia" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wireless-black-boxes-02.width-990_DC8Uc5A.jpg"/>
<figcaption>With no black-box data recorded during the final five minutes and 37 seconds of Swissair Flight 111, investigators had to seek clues to the disaster's cause elsewhere. Their in-depth investigation took place in this hangar in Nova Scotia.
        
        <div class="credit">© WGBH Educational Foundation</div>
</figcaption>
</figure>
</p>
<p>
	And when black-box recordings are lost, as was the case with the two planes that struck the World Trade Center, downloaded data may be the <i>only</i> data. (I should note here that if Swissair Flight 111 had had a real-time data link, it would have quit operating at the same moment as its flight and cockpit recorders. Like black boxes, data-link systems would rely on a plane's electrical power, which the Flight 111 pilots shut off during their attempt to isolate and fight the fire that eventually brought the plane down.)</p>
<p>
	A robust data link would also mean a lot more information than just black-box data could flow, and it could flow both ways. As it is now, aircraft, particularly when flying over oceans, are often incommunicado for long periods. "Next to a remote desert island, it's about the only place you can hide and be out of touch," one aviation expert told me. With a broadband communications link, people in the air and on the ground could be in constant, detailed contact.</p>
<blockquote>
	Most experts agree that such systems would supplement rather than replace black boxes.</blockquote>
<p>
	This would have clear benefits, most significantly the ability to cope with emergencies. If air-traffic controllers clearing aircraft for takeoff could glean pilot intent from incoming data, for example, they could reduce runway incursions, a leading cause of aircraft mishaps. "If you're polling this data every second, and you see that a pilot who hasn't been cleared is powering up and taking his foot off the brake, you know he's going to move," says Jay Brown, a computer scientist at the FAA Tech Center in Atlantic City, New Jersey. "With airplanes, it takes two or three seconds to get them to move, so you could potentially stop a runway incursion."</p>
<p>
<figure class="richtext-image full-width">
<img alt="Air-traffic controllers" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wireless-black-boxes-03.width-990_GreFgOl.jpg"/>
<figcaption>Air-traffic controllers might be better able to prevent runway incursions if they had access to up-to-the-second information coming from aircraft under their guidance.
        
        <div class="credit">© Corbis Images</div>
</figcaption>
</figure>
</p>
<h3>
	critical to routine</h3>
<p>
	During a technical emergency, pilots could get critical advice from engineers and other experts on the ground, who would have real-time knowledge of that plane's engine conditions, flight-control positions, and other essential data at their fingertips. During a hijacking, air controllers, government officials, and other key personnel could make more effective decisions, even warn possible targets. Had controllers been able to detect instantly the flight-path changes and other burgeoning anomalies on the 9/11 planes, perhaps something could have been done, at the least, to lessen the loss of life on that tragic day. Flight attendants could even better tend to mid-flight medical crises. Sensors attached to a patient, for instance, could give ground-based doctors vital signs and other measurements upon which to base potentially life-saving decisions.</p>
<p>
	Whether intentionally triggered or not, emergencies on aircraft are thankfully rare, and it is during routine operations that such a high-bandwidth link would be most continuously useful. If, for example, computers monitoring a data link could alert mechanics that a certain part of a flying aircraft was in imminent need of replacement, an airline could have that part waiting at the plane's destination. If airline staff had a real-time sense of exactly where their aircraft were at all times, they could better schedule personnel to greet planes, collect baggage, and the like. If the FAA saw that an airline was constantly monitoring an aircraft's engines—a clear safety advantage—it might extend a required overhaul from every 15,000 hours to every 20,000 hours, a significant cost saving to the airline.</p>
<h3>
	Making it work</h3>
<p>
	Several ways to develop such a system are under consideration. The FAA Tech Center, which researches, develops, and tests new aviation equipment for the FAA, has been working with the San Diego-based Titan Corporation on a prototype system architecture. It relies on existing communications links such as air phones (when an aircraft is within line of sight) and satellites (when it's not) to transmit black-box or other aircraft or cabin data to ground stations. Titan's Richard Goelz says the project grew in part out of the 1996 crash of TWA Flight 800, whose black boxes took over a week to recover, at enormous cost. "The project started with the idea that there needs to be a better way of making data like that available without an extended search," he says.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wireless-black-boxes-04.width-990_5lFeut2.jpg"/>
<figcaption>Like many crashes in the sea, the loss of TWA Flight 800 required an extensive, costly search for its black boxes (here, the USS <em>Grasp</em> at the crash site). With a real-time transmission system, flight and cockpit data would be available instantly.
        
        <div class="credit">© Department of Defense, Airman Charles L. Withrow, U.S. Navy</div>
</figcaption>
</figure>
</p>
<p>
	Another company, AeroSat Corporation of Temple, New Hampshire, has a Department of Transportation grant to demonstrate a different way of doing the same thing. Instead of air phones or satellites, AeroSat proposes using aircraft themselves as transmitter/receivers. When a plane is beyond line-of-sight, it would send its data to another flying aircraft in the fleet. That second aircraft would pass the data to a third plane, and so on down the line until one of that airline's planes is within line of sight of a ground station and can dump the data down. "It's like rain coming off a roof," says AeroSat's Bill McNary: The information passes along horizontally in a high-altitude network of daisy-chained aircraft until it can find a way down.</p>
<p>
	Regardless of approach, experts agree that the technology exists and that the amount of data to stream is quite manageable.</p>
<h3>
	Hurdles</h3>
<p>
	So what's the delay? Cost, for starters. "Purely from an accident investigation standpoint, airplanes almost never, ever crash," says Jim Cash, the NTSB's senior technical advisor for black boxes. "So to be continuously sending data off an airplane that could go its entire 40 or 50 years of flight service and never have an incident or accident—nobody's got that kind of money, especially the airline industry. It's still much cheaper to put a box on an airplane and just have it run its merry life recording data that nobody will ever look at."</p>
<blockquote>
	If there's one thing that everyone wants to know in the wake of disastrous crashes, it is what happened.</blockquote>
<p>
	Costs include designing, building, operating, and maintaining the system, which may require a series of new ground stations and/or expensive satellite time. There are also privacy and competition issues to consider. How, for instance, do you ensure, even with encryption, that only Singapore Airlines receives Singapore Airlines data? And there's no guarantee that a plane under stress won't lose its data link just when it's needed most, as would have been the case in those final six minutes of Swissair Flight 111. For this and other reasons, most experts agree that such systems would supplement rather than replace black boxes.</p>
<p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/wireless-black-boxes-05.width-990_O9fZaQN.jpg"/>
<figcaption>Since this article appeared in 2004, a passenger jet did crash mid-ocean: Air France Flight 447, which disappeared in the Atlantic on June 1, 2009 (see "Crash of Flight 447" in Related Links above). Its black boxes were not found until two years later.
        
        <div class="credit">© WGBH Educational Foundation</div>
</figcaption>
</figure>
</p>
<p>
	Despite the hurdles to wireless transmission, it may not be too far off. Aviation specialist Paul Czysz, a professor emeritus at St. Louis University, believes that all it would take to spur an official drive for a telemetry system would be the crash of a major jetliner over mid-ocean in which the black boxes were unrecoverable—"a <em>Titanic</em> event," as he calls it. "You're going to have to have something like this," Czysz says of a real-time data link, "just to make sure you know what happened."</p>
<p>
	And if there's one thing that everyone—from crash investigators to victims' families to just about anyone who ever flies—wants to know in the wake of disastrous crashes like Swissair Flight 111, it is what happened.</p>

Should airlines transmit flight and cockpit data to ground stations in real time?

Peter Tyson

Articles