The Seismic Link Between Fracking and Earthquakes

Environmentalists fear that fracking could cause more quakes if it expands to California Photo by David McNew/Getty Images

New research indicates that wastewater disposal wells—and sometimes fracking itself—can induce earthquakes

Ohio regulators did something last month that had never been done before: they drew a tentative link between shale gas fracking and an increase in local earthquakes. As fracking has grown in the U.S., so have the number of earthquakes—there were more than 100 recorded quakes of magnitude 3.0 or larger each year between 2010 and 2013, compared to an average of 21 per year over the preceding three decades. That includes a sudden increase in seismic activity in usually calm states like Kansas, Oklahoma and Ohio—states that have also seen a rapid increase in oil and gas development. Shale gas and oil development is still growing rapidly—more than eightfold between 2007 and 2o12—but if fracking and drilling can lead to dangerous quakes, America’s homegrown energy revolution might be in for an early end.

But seismologists are only now beginning to grapple with the connection between oil and gas development and earthquakes. New research being presented at the annual meeting of the Seismological Society of America this week shows that wastewater disposal wells—deep holes drilled to hold hundreds of millions of gallons of fluid produced by oil and gas wells—may be changing the stress on existing faults, inducing earthquakes that wouldn’t have happened otherwise. Those quakes can occur tens of miles away from the wells themselves, further than scientists had previously believed. And they can be large as well—researchers have now linked two quakes in 2011 with a magnitude greater than 5.0 to wastewater wells.

“This demonstrates there is a significant hazard,” said Justin Rubinstein, a research geophysicist at the U.S. Geological Survey. “We need to address ongoing seismicity.”

Rubinstein was speaking on a teleconference call with three other seismologists who have been researching how oil and gas development might be able to induce quakes. All of them noted that the vast majority of wastewater disposal sites and oil and gas wells weren’t connected to increased quake activity—which is a good thing, since there are more than 30,000 disposal wells alone scattered around the country. But scientists are still trying to figure out which wells might be capable of inducing strong quakes, though the sheer volume of fluid injected into the ground seems to be the driving factor (that’s one reason why hydraulic fracturing itself rarely seems to induce quakes—around 5 million gallons, or 18.9 million L, of fluid is used in fracking, far less than the amount of fluid that ends up in a disposal well).

“There are so many injection operations throughout much of the U.S. now that even though a small fraction might induce quakes, those quakes have contributed dramatically to the seismic hazard, especially east of the Rockies,” said Arthur McGarr, a USGS scientist working on the subject.

What scientists need to do is understand that seismic hazard—especially if oil and gas development in one area might be capable of inducing quakes that could overwhelm structures that were built for a lower quake risk. That’s especially important given that fracking is taking place in many parts of the country—like Oklahoma or Ohio—that haven’t had much experience with earthquakes, and where both buildings and people likely have a low tolerance to temblors. Right now there’s very little regulation regarding how oil and gas development activities should be adjusted to reduce quake risk—and too little data on the danger altogether.

“There’s a very large gap on policy here,” says Gail Atkinson, a seismologist at the University of Western Ontario. “We need extensive databases on the wells that induce seismicity and the ones that don’t.”

So far the quakes that seem to have been induced by oil and gas activity have shaken up people who live near wells, but haven’t yet caused a lot of damage. But that could change if fracking and drilling move to a part of the country that already has clear existing seismic risks—like California, which has an estimated 15 billion barrels of oil in the Monterey Shale formation that could only be accessed through fracking (limited fracking has been done in California, but only in the lightly populated center of the state). Environmentalists who seek to block shale oil development in the Golden State have seized on fears of fracking-induced quakes, and a bill in the state legislature would establish a moratorium on fracking until research shows it can be done safely.

Regulation is slowly beginning to catch up. In Ohio, officials this month established new guidelines that would allow regulators to halt active hydraulic fracturing if seismic monitors detect a quake with a magnitude of 1.0 or higher. But it will ultimately be up to the oil and gas industry to figure out a way to carry out development without making the earth shake.

“I am confident that it is only a matter of time before we figure out how to exercise these technologies in a way that avoids significant quakes,” says Atkinson. Otherwise the fracking revolution may turn out to be short-lived.

TIME plants

Talking Tomatoes: Sick Plants Warn Their Neighbors

Chatterbox: tomato plants have a lot more to say than you'd think
Chatterbox: tomato plants have a lot more to say than you'd think John Burke; Getty Images

Chemical signaling allows healthy plants to defend themselves when a single neighbor is under attack—a result of communication among species that were always thought to be entirely mute

We tend to think of plants as basically inert—the furniture of the natural world. They don’t move, they don’t make sounds, they don’t seem to respond to anything—at least not very quickly. Grass doesn’t cry when you cut it, flowers don’t scream when they’re picked. But as is often the case, our human-centric view of the world misses quite a lot. Plants are talking to each other all the time. And the language is chemical.

Over the last few decades, a growing stream of papers has reported that different types of plants, from trees to tomatoes, release volatile compounds into the air for the benefit of neighboring plants. These chemical smoke signals come in many varieties, but their purpose seems to be to spread information about one plant’s disease or infestation so other plants can defend themselves. That’s been the general idea anyway, but exactly how plants receive and act on many of these signals is still mysterious. In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offer some explanations, announcing that they’ve identified one such chemical message and traced it all the way from emission to action.

The experimenters looked at tomato plants infested by a common pest, the cutworm caterpillar. To start out, they grew plants in two plastic chambers connected by a tube, with an infested plant in the upwind chamber and an uninfested one downwind. When those downwind plants were later exposed to the cutworm pest, they defended themselves against it better than tomato plants that had not been exposed to a sick neighbor.

The researchers analyzed leaves from exposed and unexposed plants and found that out of the 8,226 compounds identified, only one showed up more frequently in the exposed plants, a substance called HexVic. And indeed, when the researchers fed HexVic to cutworms, it knocked down their survival rate by 17%.

Looking for the source of this protective substance, the scientists fingered a chemical precursor to HexVic among the cocktail of volatiles released by the infested plants. When they wafted it over uninfested plants, the plants began to produce HexVic, suggesting that they were turning the volatile into the caterpillar-killing chemical. A series of other tests confirmed that idea: Uninfested plants don’t have this precursor lying around, and must build their own weapon from the early warning message released by their infested relatives.

It’s an elegant tale, and it may be happening in far more plant species than tomatoes and with far more chemical signals that are still unintelligible to us. For now though, it’s hard not to have at least a little more respect for a type of life that not only communicates but, in its own invisible way, looks after its kin.



Why Science Needs More Sex

What Duckpenisgate tells us about ourselves

In March 2013, Yale University biologist Patricia Brennan, who studies the evolution of birds’ reproductive organs, found herself in the path of a two-week media cyclone. Brennan had secured a $390,000 National Science Foundation grant for her work on duck genitalia. Conservative news site CNSNews.com found out about this and ran a story on it, which sparked nation-wide outrage (quickly dubbed “Duckpenisgate”) at the spending of tax dollars on research as frivolous as studying the nether regions of waterfowl.

We genital researchers are used to getting giggly or derisive responses when we try to explain our work. It has been like that ever since this particular branch of evolutionary biology was kick-started, back in 1979. In that year, in the journal Science, Brown University’s Jonathan Waage reported that male damselflies use their penis not just to squirt sperm into the female’s vagina, but also to scrape out any remaining sperm of her previous trysts. When I interviewed Waage for my book Nature’s Nether Regions, he recalled that one magazine covered the news with a derogatory headline like, “University Egghead Wastes Taxpayers’ Money Studying Dragonfly Sex”.

The egghead headline and Duckpenisgate bracket three and a half decades during which the study of the evolution of penises, vaginas, and their equivalents throughout the animal kingdom has matured into a solid biological discipline, with hundreds of my fellow scientists worldwide working on it. However, if we are to believe our vociferous critics, we have all been sidetracked into a perversion of publicly funded science, following our own deviant fascinations with the sordid sex lives of inconsequential creepy-crawlies, rather than pursuing research that benefits society.

I could of course retort by pointing out that our field has, on occasion, yielded direct applications. Artificial insemination in livestock has been improved by more effectively-shaped pipettes, and certain gynecological problems can also be understood if we take an evolutionary view.

Such practical spin-offs are all-too-often paraded by basic science as a justification, or even a motivation for its existence. But deep down we all know this to be only part of the story. The desire to understand nature, and the great satisfaction when we succeed, is what really drives us genitalia researchers, and technological or medical applications of our research are little more than a beneficial side-effect.

But that is not to say that our work is a solipsistic exercise for evolutionary biologists only. I think basic science should be mentioned in the same vein as art, music, or top-class sports, which also serve no practical purpose but provide entertainment to the rest of humankind. Evolutionary biologists do the hard scientific labor that leads to the discoveries that allow us to tell true tales about the way nature works. Billions of people watch nature documentaries about amazing wildlife in far-away corners of the globe. But the facts dished out are not discovered by their khaki-clad presenters. Instead, every minute of footage required a dedicated, publicly-funded biologist, sometime, somewhere, doing the painstaking basic research and furnishing a previously unknown plant or animal with its fifteen minutes of National Geographic fame.

And if anything about nature is entertaining, it should be all the weird and wonderful ways in which animals have sex. The list of mind-bending facts is endless.

Think snails that impale one another with hormone-laced daggers; she-spiders that force their partners to four hours of foreplay and galago ladies that demand equally drawn-out afterplay; slugs with (literally) yard-long penises that take a whole night to erect; a rove beetle with a coiled-up vagina three times longer than her body; insect semen that leaches holes in the vagina wall, makes a female frigid, congeals into a cement-like plug, or otherwise misbehaves…

These snippets of the outlandish sexual habits of many animals are already highly entertaining in themselves and make good party stories, if nothing else. But they become even more fascinating when they are strung together into a rosary in veneration of evolution’s greatest feats.

Evolution, after all, is all about reproduction: if you’re better at it, you leave more descendants, who inherit your DNA with its superior reproductive abilities, and go on to be successful procreators themselves. All that survival of the fittest stuff is fine, but if you really want to be an evolutionary success, then invest in being better at sex. That is why the evolution of animal genitalia progresses at such a breakneck speed, causing even the most similar species to have wildly different boy and girl bits.

In fact, the evolution of reproductive plumbing is being pushed along even more urgently by a second engine: the conflict between the sexes. Being good at sex — evolutionarily speaking — for a female means choosing wisely from among the available sperm donors. But being good at sex as a male usually means making sure that as many females as possible choose you as their exclusive sperm donor.

Such a conflict of interest pervades the evolution of reproductive organs in animals. But not only in animals: we humans fit right in. Above, I made the claim that gynecological problems can be understood if we take an evolutionary view. For example, scientists have discovered that preeclampsia, a dangerous inflammation in pregnant women—essentially an allergic reaction of the mother’s body to her own fetus —can be reduced by regular exposure of the woman to semen of her baby’s father, either by unprotected vaginal sex or via oral sex. The evolutionary interpretation of this curious medication? Proteins in semen have evolved to take control of the woman’s immune system and protect the father’s interests by suppressing the allergic reaction — even if it were healthier for the mother’s body to abort an overdemanding fetus.

Another gynecological problem are so-called ectopic pregnancies. Sometimes an embryo will implant itself outside of the uterus — for example in the fallopian tube, or even inside the ovaries themselves. It turns out that some of these pregnancies are caused by rogue sperm that do not stay within the legitimate confines of vagina and uterus, but wiggle their way through organ walls and go cross-country, as it were, through the woman’s abdomen, looking for fertilizable eggs.

Such all-terrain sperm are to be expected, and, in fact, similar sperm behavior is found all across the animal world. Again, the problem can be understood if we see that evolution will smile on sperm that do not let themselves be restricted by the boundaries imposed by the female. Such new and refreshing ways of viewing human reproduction can only be achieved thanks to decades of trying to understand animal sex. Populist media may balk at spending public money on such studies. But the field has not only given us the greatest stories from the Kama Sutra of creepy-crawlies, it has also paved the way for gynecologists, urologists, and evolutionary biologists to sit down and draft a research program to gain a deeper understanding of human sexuality and reproduction. Nothing perverse about that.

Menno Schilthuizen is an ecologist and evolutionary biologist based at Naturalis Biodiversity Center in Leiden, the Netherlands, and is the author of Nature’s Nether Regions: What the Sex Lives of Bugs, Birds, and Beasts Tell Us About Evolution, Biodiversity, and Ourselves.


It’s Time to Stop Ignoring the Bad Air We Breathe

Air pollution
Nearly half of Americans breathe unhealthy air Photo by David McNew/Getty Images

A survey shows nearly half of all Americans breathe unhealthy air — but air pollution doesn't get the attention it deserves

Take a look outside your window. Chances are the air you’ll see is far cleaner than it was decades ago. Since 1980 levels of ozone pollution — one of the main ingredients in smog — have fallen by 25% in the U.S., while nitrogen dioxide has fallen by 55% and sulfur dioxide by 78%. The change is visual too — the smog-obscured skies that were once a constant backdrop to cities like Los Angeles in the 1960s and ’70s are far less common. It’s easy to assume that America won the war on air pollution, and to look with pity on developing cities like Beijing and New Delhi where the air is still poisoned.

There’s just one problem with that sense of satisfaction: the data doesn’t back it up. According to a new report from the American Lung Association (ALA), nearly 148 million Americans live in areas where smog and soot particles have led to unhealthy levels of pollution. That means that for almost half of all Americans, simply breathing can be dangerous. Even worse, the report shows that some aspects of air quality have been deteriorating over the past few years in many cities — from 2010 to 2012, ozone worsened in 22 of the 25 biggest metropolitan areas, including cities like New York and Chicago. “Air pollution is not just a nuisance or the haze we see on the horizon; it’s literally putting our health in danger,” Bonnie Holmes-Gen, senior policy director of the ALA in California, told the Los Angeles Times. “We’ve come a long way, but the status quo in not acceptable.”

The news is far from all bad. Thanks in part to the retirement of a number of older coal-fired power plants, levels of particulate pollution — soot, in other words — have been dropping in recent years, with cities like Philadelphia and Indianapolis recording their lowest levels yet. And historically, we’re far better off — as Brad Plumer notes over at Vox, air pollutants as a whole have fallen 72% since the Clean Air Act was passed in 1970, even as the economy, population and energy use have all risen.

But as the ALA report makes clear, some of that progress is being lost, in part thanks to climate change — one environmental challenge we’re very much not meeting. Rising levels of ozone pollution have been linked to warmer temperatures, which will make it that much tougher to fight smog in the future. And the government could have done more — in 2011, President Obama went against the recommendations of the Environmental Protection Agency (EPA) and rejected a proposal that would have tightened the ozone standard to between 60 and 70 parts per billion. (The level is currently at 75 ppb, set by former President George W. Bush, who was not exactly known as an environmental paragon.)

Those regulatory battles matter because it’s becoming increasingly clear that healthy air is a moving target. The more scientists learn about the health impacts of air pollution, the more dangerous it appears — even at comparatively low levels. Last October the World Health Organization (WHO) officially declared air pollution to be a carcinogen, connecting it directly to lung cancer as well as bladder cancer. And bad air doesn’t just hurt the lungs — a raft of studies have connected air pollution, especially soot, to cardiovascular disease, even triggering heart attacks. Even autism has been linked to pollution. In March the WHO estimated that outdoor air pollution caused 3.7 million premature deaths globally in 2012 — nearly three times the number of people who die each year from tuberculosis.

Climate change gets most of the environmental attention, with reason — its effects are already being felt, and it has the potential to radically change our world for the worse. But air pollution is sickening and killing millions of people around the world right now. And unlike global warming, the technological and regulatory solutions to conventional air pollution already exist. That’s why it was good news yesterday when the U.S. Supreme Court upheld the EPA’s ability to control coal-fired power-plant emissions in 28 states. The decision excited greens because it indicates the court will eventually back even more controversial carbon regulations that the Obama White House is busy formulating now, but the regulation that was upheld — the Cross-State Pollution Rule — will prevent an estimated 45,000 deaths a year from conventional air pollution once it’s in place.

Air pollution remains stubbornly difficult to eliminate, in part because of the vagary of the wind itself, which separates the victims of pollution from its source. As Justice Ruth Bader Ginsburg wrote in her decision yesterday, quoting from the Book of John: “The wind bloweth where it listeth, and thou hearest the sound therof, but canst not tell where it cometh, and whither it goeth.” But if we can’t control the air, we can control what we put into it — and protect ourselves.


TIME Death Penalty

There Is No Such Thing as a Safe Execution

Last stop: clean, painless lethal injections are becoming anything but
Edward McCain—Getty Images

A botched lethal injection in Oklahoma reveals the growing mess the American death penalty is becoming.

Never mind all that talk about Oklahoma’s botched execution of Clayton Lockett, who was supposed to be put to death yesterday by lethal injection and instead died of a massive heart attack when one of the lines running into his arm blew out, causing the vein to rupture. He’s dead, ain’t he? Job done.

That’s one of the historical problems with the whole business of executions, of course: they are designed to end a condemned person’s life, but the process is supposed to be conducted just so—cleanly, predictably, ceremonially, so that the sanctioned taking of a life is somehow distinguished from the homicide for which the condemned person is usually dying. That’s the reason too for some of the absurdities in the execution rituals, like loading one of the guns used in a firing squad with a blank, so that all of the riflemen can later tell themselves they may have done no killing; or using an alcohol swab on the spot on the arm into which a needle will be inserted, which prevents germs on the skin from entering the body and causing an infection later on—hardly necessary when later on will come long after the person is dead.

But the thing is, even the most carefully designed medical procedure—and whatever else an execution via lethal injection is, it’s that—is not entirely without risk. In 2010, the National Institutes of Health conducted a study on 333 patients to determine whether ultrasound should be used to help guide the insertion of a central venous catheter, a line threaded into one of the body’s major vessels to deliver fluids or steady doses of medication. The procedure carries up to a 15% rate of complications, including infection, bleeding, clots around the catheter and, depending on placement of the line, collapsed lungs. And that’s when highly trained people are working on large, hard-to-miss vessels.

(Read More: Every Execution in U.S. History in a Single Chart)

Much of the debate swirling around the Lockett case involves the mix of three chemicals that were used in the execution, which had never been tried in Oklahoma before, and the increasing unavailability of more familiar drugs as pharmaceutical companies balk at allowing their use in capital punishment. Similarly, as medical personnel also refuse to participate in executions, the job is often being done by prison officials whose training may be inadequate.

But let’s assume the best-case scenario—with just the right drugs and just the right experts injecting them. The Death Penalty Information Center has compiled a list of 44 botched executions—32 of them by lethal injections—many from the 1980s and 1990s, when those ideal conditions prevailed. There was the 1988 execution of Raymond Landry in Texas, which went south when the line administering the drugs came loose, spraying the deadly cocktail of chemicals around the room; there was John Wayne Gacy in Illinois in 1994, whose execution was stopped and restarted when the drugs mysteriously hardened, forming a clot in the line; there was Joseph Cannon in Texas in 1998, whose vein collapsed during the procedure, causing the needle to pop out. “It’s come undone,” the condemned man informed the witnesses, which may or may not have been his last words.

Often, problems during lethal injections are caused by poor veins resulting from a history of intravenous drug abuse. But other times, the prisoner is fit. In the case of Lockett, the director of the Oklahoma Department of Corrections blamed vein failure, but Lockett’s attorney, David Autry, disagrees.

(Read More: Oklahoma’s ‘Constitutional Crisis’ Ends With Execution Date Set)

“I’m not a medical professional,” he told the Associated Press, “but Mr. Lockett was not someone who had compromised veins. He had large arms and prominent veins.” If that’s so, and a full investigation of the mess is still very much under way, the problem could instead have been caused by the multiple lines—one in each arm, which doubles the odds of error—or the untested nature of the particular drug combination.

Whatever the cause, the great certainty is that executions have never been—and will never be—foolproof. Nooses fail to kill cleanly, electrocutions set fire to skin, asphyxiating gases cause convulsing and head banging. There is no denying that many of the people we put to death are the worst of the worst; Gacy raped and killed at least 33 boys and men. “If a man ever needed dyin’ he did,” as the song lyric once went. But it’s still for us to decide how we want to answer that need—either by execution or, even in the case of a monster like Gacy, life behind bars. If we do decide to kill, we should not pretend we’ll ever get it completely right.

TIME animal

And the World’s New Fastest Land Animal Is…

Paratarsotomus macropalpis

Researchers have used film to determine that the world's fastest land animal is not a cheetah but a mite no larger than a sesame seed. The paratarsotomus macropalpis trounces the big cat by moving a crazy 322 body lengths per second to the cheetah's 16

A tiny mite no larger than a sesame seed holds the record as the fastest land animal in the world, according to new research, when measured in proportion to its size.

While the cheetah is commonly thought of as one of the speediest creatures in the animal kingdom, and moves at 16 body lengths per second, the Paratarsotomus macropalpis trounces the big cat with a whopping 322 body lengths per second, according to a study by Pomona College in Claremont, Calif. This is almost twice as quick as what was previously believed to be the fastest animal, the Australian Tiger Beetle, which moves at 171 body lengths per second.

Because of the mite’s minuscule proportions and inordinately fast pace, the research team was unable to use traditional means of measuring its velocity. “We can’t actually chase after a mite because they move much too quickly for that,” said Jonathan Wright, lead researcher of the study. “We’re actually filming them running on a concrete driveway.”

After gathering the footage, the researchers then replayed the film to find that the mite’s speed exceeded their expectations and that it was also able to quickly switch its direction.

The findings were presented at the Experimental Biology 2014 meeting in San Diego on Sunday.


Neil deGrasse Tyson Tries To ‘Learn Something New Every Day’

From left: Neil deGrasse Tyson and Dr. Mehmet Oz attend the TIME 100 Gala, TIME's 100 most influential people in the world, at Jazz at Lincoln Center on April 29, 2014 in New York City.
From left: Neil deGrasse Tyson and Dr. Mehmet Oz attend the TIME 100 Gala, TIME's 100 most influential people in the world, at Jazz at Lincoln Center on April 29, 2014 in New York City. Larry Busacca—Getty Images for TIME

The astrophysicist can't get enough

There’s never enough knowledge for rockstar astrophysicist Neil deGrasse Tyson.

“I try to learn something new every day or else the day is wasted,” deGrasse Tyson said during a brief interview at the TIME 100 gala Tuesday in New York.

Arriving in a starry-night waistcoat and chatting with TV talk show host Dr. Oz, deGrasse Tyson said he was most looking forward to meeting “the people I’ve never heard of who are changing the world. The famous people we already know about.”

So what’s the last thing deGrasse Tyson learned? Well, it’s something he thought he already knew, but the rate of supernovas exploding in our galaxy is actually twice what was reported on his show Cosmos.

TIME Environment

From ‘Gale’ to ‘Inconceivable,’ Ranking Tornado Strength

Ranking tornado strength
Deadly tornadoes devastated the town of Vilonia, Arkansas on Apr. 27 Mark Wilson/Getty Images

As tornadoes blast across the southeastern U.S., a look at how officials gauge just how powerful a killer twister is

Tornado season began with a crash in the southeastern U.S. this week, where dozens of twisters ripped across Mississippi, Arkansas and Alabama. At least 29 people have died in the storms — and with more tornadoes forecast as the weather system moves further east, that number will almost certainly rise.

It’s the suddenness of tornadoes, as much as their power, that accounts for the lives they take. Meteorologists can forecast when and where storms that can produce tornadoes will appear, but they can rarely give residents more than 15 minutes of warning before a twister touches down. Unlike hurricanes, which meteorologists can now track days in advance with increasing precision, tornadoes remain stubbornly unpredictable, although forecasters at the National Oceanic and Atmospheric Administration (NOAA) are working on ways to extend that warning time.

That unpredictability also makes it harder to assess the destructive power of a tornado in real time. Hurricane categories are based on sustained wind speeds in a storm—a Category 1 storm would have sustained winds 74-95 mph (119-153 kph), while a Category 5 storm would have sustained winds of over 157 mph (252 kmh) (“Sustained wind speeds” means the average wind speed in a storm over 10 minutes). The damage a hurricane can cause doesn’t always conform completely to categories. Superstorm Sandy, for instance, wasn’t even a Category 1 hurricane by the time it made landfall in New Jersey, but still caused more than $60 billion in damage, largely due to the size of its storm surge. But more wind generally means more danger—just ask the people of New Orleans, hit by Category 5 Hurricane Katrina in 2005.

Tornado strength is assessed on a different and slower scale, after the twisters have struck. When tornadoes occur, National Weather Service (NWS) officials are dispatched to survey the damage. They also reconstruct tornadoes’ life cycles, where they touched down—and how strong they were. Tornadoes are ranked on the Enhanced Fujita (EF) Scale, developed by a Japanese-American meteorologist who, not coincidentally, got his start studying the damage caused by the atomic bomb in Hiroshima. The original Fujita scale was based primarily on the damage a tornado did, with wind speed estimated after the fact. The scale ranked tornadoes from a F0 (Gale) to an F5 (Incredible), with an unofficial F6 category that would require winds in excess of 318 mph and which goes by the name Inconceivable—accurate, since no F6 tornadoes have ever been recorded.

The Enhanced Fujita scale was adopted in 2007. It was designed to more accurately reflect the actual damage a tornado had done on the ground. The EF scale uses 28 different damage indicators, ranging from small barns to hardwood trees to shopping malls—and each of those indicators is assessed based on several different points of possible damage. A shopping mall could range from damage that is just barely visible to complete destruction of some or all of the building. There’s a large database of how strong a tornado needs to be to cause certain kinds of structural damage, so meteorologists are able to use the final damage report to go back and estimate the tornado’s wind speed at the time of touchdown. The categories range from EF0—with three-second wind gusts of 65-85 mph (104-137 kph)—to EF5, with three second gusts over 200 mph (321 kph).

We won’t know the full strength of this week’s multiple tornadoes until NWS surveyors have had a chance to measure the damage on-site. But there has already been a pair of EF3 twisters this year, striking Arkansas and North Carolina on Apr. 27, and those tornadoes may be upgraded as full damage assessments are carried out. 2014 had been shaping up to be a quiet year for tornadoes—Apr. 27 marked the end of a string of 159 days without an EF3 or above tornado, and there had been only 93 tornado reports this year through Apr. 24. That changed this week—there were 87 tornado reports on Apr. 28 alone. And while no tornado that’s hit yet looks to be as strong as the EF5 twister that devastated Moore, Oklahoma last year, the season is far from done.

TIME health

Solving the Mystery Flu That Killed 50 Million People

The deadly 1918 flu pandemic
The 1918 flu pandemic killed an estimated 50 million people Photo Researchers via Getty Images

Researchers have wondered for decades why the 1918 flu disproportionately killed so many young people, but a new study in the Proceedings of the National Academy of Sciences suggests the answers are in the pattern of past flu infections

Years ago the environmental historian Alfred Crosby was at Washington State University, where he was teaching at the time, when on a whim he decided to pick up an old almanac from 1917. (This is apparently the kind of thing historians like to do in their spare time.) He looked up the U.S. life expectancy in that year—it was about 51 years. He turned to the 1919 almanac, and found about the same figure. Then Crosby picked up the almanac from 1918. The U.S. life expectancy in 1918 had fallen to 39 years. “What the hell happened?” Crosby told the New York Times writer Gina Kolata in her book Flu: The Story of the Great Influenza Pandemic of 1918. “ The life expectancy had dropped to what it had been fifty years before.”

What happened was the 1918 influenza pandemic. A virus that usually does little more than make people feel awful for a few days killed an estimated 50 million people worldwide, if not far more, with 650,000 people dying in the U.S. alone. The flu killed more people in a year than the bubonic plague killed in a century in the Middle Ages. Worst of all, this flu disproportionately took the lives of men and women in their 20s and 30s, while often sparing the very old and the very young—two population groups that are especially vulnerable to the flu in most years.

This has confounded scientists for almost a century, but a new study in the Proceedings of the National Academy of Sciences (PNAS) puts forward a fresh answer to one of the enduring mysteries of medical science. Researchers led by Michael Worobey of the University of Arizona reconstructed the origins of the 1918 pandemic, concluding that the pathogen arose when an existing human H1 flu virus acquired genetic material from a bird flu virus. That new H1N1 flu virus was able to evade immune systems, which helps explain why it infected more than a quarter of the U.S. population at the time. But it was young adults between the ages of 20 and 40 that died in the greatest number—and Worobey’s study suggests that the unusual death pattern was due as much to flus of the past as it was to the flu of 1918. “Prior immunity, or lack of it, seems to be the decisive factor,” says Worobey.

Flu viruses are constantly changing and mutating, which is why we can’t develop a lifelong vaccine for it the way we can for more stable viruses, like the ones that cause smallpox or the measles. A flu virus has two parts: hemagglutinin and neuraminidase proteins, shortened to HA and NA (and just H and N when naming a virus). It’s the HA protein that seems to drive our immune system response, as Worobey put it in a statement:

Imagine a soccer ball studded with lollipops. The candy part of the lollipop is the globular part of the HA protein, and that is by far the most potent part of the flu virus against which our immune system can make antibodies. If antibodies cover all the lollipop heads, the virus can’t even infect you.

Worobey and his colleagues looked back at the kinds of flu viruses that were in circulation in the decades preceding the 1918 pandemic by examining antibodies found in old blood samples. (Your immune system will produce customized antibodies in response to a flu infection, and those antibodies will remain in your body, which allows scientists to identify the genetic makeup of the virus that led to their creation.) It turns out people born between 1880 and 1900—the generation hit hardest by the 1918 flu—were mostly exposed during childhood to a H3N8 flu virus that began circulating during an earlier pandemic in 1889, but not to an H1 virus, which meant that generation had virtually no antibodies to fight it off.

By reconstructing the genetic origins of the 1918 flu, Worobey found that a version of that H1N1 flu virus was circulating for years before the pandemic began. Because flu strikes most commonly in childhood, those born after 1900 were more likely to have had previous exposure to an H1N1-like flu virus, which would have offered them some protection. Meanwhile those born before 1880 were more likely to have been exposed to the H1N8 flu strain that was prevalent when they were children. In both the very young and the old, having earlier exposure to an H1 flu—even one different from the strain that caused the 1918 pandemic—offered a level of protection not present in those who had never been infected by an H1 strain. That could explain the unusual mortality curve in the 1918 pandemic.

1918 flu mortality curve
The researchers found a remarkable overlap between death rates in various age groups in 1918 and childhood exposure to an H3 flu virus that was mismatched with H1N1 pandemic virus. Credit: Michael Worobey

Thankfully, no flu pandemic since 1918 has been anywhere near as deadly. The 2009 swine flu pandemic killed an estimated 284,000 people worldwide, comparable to flu deaths in a non-pandemic year. But two avian flu viruses — H5N1 and H7N9 — have for years been periodically jumping the species barrier and infecting human beings. And like the 1918 flu, H5N1 and H7N9 are unusually deadly, particularly for the young and elderly, respectively. “Lots of different age groups might be exposed to these viruses, but the virus that kills them is the one that’s mismatched to the virus they encountered as a child,” says Worobey.

The PNAS paper suggests that this might be due to past flu patterns as well, with both groups having been exposed to flu viruses in their youth that offered them little protection against the new pathogens. If either virus were to mutate to the point where it could spread easily in the human population, the results could be catastrophic.

But the PNAS paper offers hope that doctors could begin to design flu vaccination strategies that compensate for the strains that different age groups never experienced as children. Down the line, scientists may even be able to develop a universal flu vaccine that targets parts of the virus that almost never change from strain to strain. “This work is encouraging that possibility,” says Worobey. If we’re smart, the global catastrophe that was the 1918 pandemic will remain confined to the history books.

TIME space

CSI NASA: Using Old Space Images to Find New Planets

Images of planetary disks from Hubble
The two images at top reveal debris disks around young stars uncovered in archival images taken by NASA’s Hubble Space Telescope. The illustration beneath each image depicts the orientation of the debris disks NASA/ESA, R. Soummer, Ann Feild (STScI)

A team of scientists from the Space Telescope Science Institute is using image-recognition software and new algorithms to re-analyze existing Hubble images of space in the hopes of finding new stars and planets

When detectives use DNA to crack a cold case, or when defense attorneys use it to free the wrongly convicted, the evidence itself can date back years—in some cases, to a time before DNA forensics had even been invented. No police officer imagined when they took hair or blood or tissue samples years ago that such tests would ever be invented.

Now something similar is happening in astronomy. A team of scientists from the Space Telescope Science Institute has re-analyzed old Hubble images with new software algorithms to reveal disks of dusty material around five young stars—an indirect hint that unseen planets are lurking there as well. “We had evidence that these disks might exist,” says Rémi Soummer, the institute astronomer who led the project, “but we had no idea about their size or structure.”

Some of that evidence dates all the way back to the early 1980s, when a satellite known as IRAS detected excess infrared radiation coming from a number of nearby stars. The best bet was that it was coming from orbiting dust particles, created when rocky asteroids smashed into each other—an early hint that the building blocks of planets were common around other stars. In 1984, astronomers using ground-based telescopes even managed to take images of a disk-shaped dust cloud swirling around the star Beta Pictoris.

But for more distant stars, it’s proven very tough to take images of dusty disks, even with the powerful Near Infrared Camera and Multi-Object Spectrometer (NICMOS), installed on Hubble during a 1997 shuttle mission. Like blood samples preserved in police evidence room, however, those images have been sitting in electronic storage in the Mikulsko Archive for Space Telescope database. (It’s named for Hubble-friendly Senator Barbara Mikulski, who represents Maryland, where the space telescope institute is located.)

In 2011, Soummer plunged back into that archive with a newly developed image-processing algorithm similar to those used in face-recognition software, and “discovered” three planets orbiting a star called HR 8799, about 130 light-years from Earth. The planets had already been found with ground-based telescopes between 2007 and 2010, but the pictures Soummer analyzed dated all the way back to 1998. (University of Montreal astronomer David Lafreniere found a fourth planet in the same system with similar image-processing techniques in 2009).

“It was great that we could see the planets in these old images,” Soummer says, but it was even better that they could now note the planets’ positions. Comparing them with the newer images, he says, “we could see a bit of orbital motion.” That’s crucial in understanding the dynamics of this distant solar system, but also in proving that the tiny dots of light hugging the star aren’t actually background stars that happen to lie along the same line of sight.

That success inspired Soummer and his colleagues to scrutinize archived NICMOS images of 400 additional stars. “Once we knew we could find planets that were already known,” he says, “we knew we could apply our technique to find entirely new stuff.”

They developed a new, faster algorithm, which turned out to be better at finding diffuse objects than it was at finding pointlike planets. They focused on stars that showed excess infrared light, figuring that this is where they’d likely find planet-forming dust disks—and ultimately, they discovered five, along with hints about their structure. In one case, the dust disk has a sharply defined inner edge, hinting at a still unseen planet “shepherding” the dust with its gravity. In another, the star in question, known as HD 141943, is an almost exact twin of our Sun. It’s only about 30 million years old, though, which puts it right at the age when the planets in our own Solar System formed. It’s like looking at a baby picture of the Sun and its newborn family.

And that’s just the start. “We’re only halfway through our observing program,” says Soummer. “We’re hoping to find new planets and new disks around many of these stars.” They’re also hoping to apply their algorithm to images from the James Webb Space Telescope, which will be far more powerful and sensitive than even the Hubble once it’s operational in 2018. The Webb has every prospect of revolutionizing scientists’ understanding of how planets form, around what kinds of stars, out of what raw materials—and unlike the Hubble, it presumably won’t have to leave its images sitting in an evidence locker, waiting for someone to figure out how to process them.


Your browser, Internet Explorer 8 or below, is out of date. It has known security flaws and may not display all features of this and other websites.

Learn how to update your browser