The Mississippi River is cresting at a near-record 48 feet in Memphis today — 14 feet above flood stage — but the Big Muddy is still far from finished. While levees are expected to hold back devastating floods in Memphis, that city and others nearby will remain at risk for weeks. Plus, the crest is continuing south down the river, potentially bringing unprecedented floods to Louisiana and Mississippi. It's the worst Mississippi River flooding in more than half a century, and as the National Weather Service's Jim Belles told reporters Monday, it won't end after the river crests: "It takes a long time to produce a flood like this on the Mississippi. It takes a while for the water to [recede]."
Many low-lying neighborhoods around Memphis have been abandoned for days, and although officials have been monitoring at least one leak in a local levee, they don't expect a disaster. "Any time we put this much pressure on the levees, we have opportunity to have some problems," says Cory Williams, a geotechnical engineer with the U.S. Army Corps of Engineers, adding that most levee problems in Memphis should be minor. The river will likely stay at or near crest for a week, the Memphis Commercial Appeal reports, and may not even fall below 40 feet before June. Meanwhile, flooding has continued in Missouri and Illinois even though the river crested there days ago, while Louisiana is forecast to see the river crest sometime next week. Nearly two dozen parishes have already issued emergency declarations in anticipation of floodwaters, and the Corps also opened a spillway north of New Orleans Monday in hopes of alleviating floods along the Lower Mississippi River.
The fuel for all this flooding has been a bizarre amount of rain falling on the Mississippi and Ohio river valleys, CNN reports — during one recent two-week span, for example, the region received 600 percent more precipitation than usual. And as the AP reports, this is part of a trend toward wilder weather across the U.S., possibly due to La Niña. Six states set records last month for their wettest April since 1895 — including Kentucky, which received triple its usual April showers — even as the U.S. also saw the most acres burned by wildfire in April since 2000. Throw in the record-shattering 875 tornadoes spawned across the U.S. last month, and it adds up to a chaotic mix. For the next few weeks, though, most people's attention will remain focused on the crisis at hand: the rising Mississippi River. "It's a river in rage right now," says Bob Nations, director of emergency preparedness for Shelby County, Tenn. "It's not close to over."
For the first time ever, a scientific study has linked the gas-drilling technique called hydraulic fracturing — aka fracking — with extreme methane contamination in nearby water wells. Published in the Proceedings of the National Academy of Sciences, the study by Duke University researchers is a groundbreaking discovery in the hotly contested battle over fracking, which allows natural gas to be extracted from shale rock, but which is also criticized for endangering water supplies. "At least some of the homeowners who claim that their wells were contaminated by shale-gas extraction appear to be right," says Duke biologist and study co-author Robert Jackson.
Jackson and his colleagues analyzed water samples from 68 private groundwater wells across five counties in northeastern Pennsylvania and New York — areas at the epicenter of a recent shale-gas boom focused on the Marcellus Shale. They found no evidence of contamination from the toxic chemicals in fracking fluids, which are injected deep underground to loosen shale deposits, or from the wastewater that's pumped out of the wells afterward. But they did find evidence of methane contamination in 85 percent of the samples, with levels of the explosive gas measuring 17 times higher than normal at wells located within 1 kilometer of active hydraulic fracturing sites. The worst contamination was found in Bradford and Susquehanna counties in Pennsylvania.
The study's biggest news, however, is that it managed to trace the source of the methane to shale deposits that gas companies are drilling into. That, Jackson says, is all but a smoking gun. "Deep gas has a distinctive chemical signature in its isotopes," he says. "When we compared the dissolved gas chemistry in well water to methane from local gas wells, the signatures matched."
A diver will soon plunge into the Atlantic Ocean off the Florida coast, carrying a device that could allow the first true, real-time conversation between a human and a dolphin, New Scientist reports. The computer is being designed to recognize dolphin sounds and generate appropriate responses in real time, potentially paving the way toward two-way communication between our species. This differs from previous dolphin research, which focused on one-way communication, explains Wild Dolphin Project founder Denise Herzing. "They create a system and expect the dolphins to learn it, and they do, but the dolphins are not empowered to use the system to request things from the humans," she says.
Even under those circumstances, captive bottlenose dolphins have demonstrated they can keep track of more than 100 words, and even seem to understand syntax. They respond to commands differently depending on word order, for example, helping them differentiate between requests such as "bring the surfboard to the man" and "bring the man to the surfboard." Herzing wants to translate dolphins' natural language rather than teaching them ours, and she has collaborated with artificial-intelligence researchers at the Georgia Institute of Technology to develop a sort of compromise called Cetacean Hearing and Telemetry, or CHAT. The project aims to work with dolphins to "co-create" a language that employs aspects of sounds wild dolphins naturally use to communicate.
That won't be easy, of course, since dolphins produce sounds beyond human hearing range, and also project them in various directions without turning their heads, making it hard to know which dolphin "said" something. To develop their shared language, the researchers will send a diver into the Atlantic wearing a smartphone-sized computer as well as two underwater microphones that can detect the full range of dolphin sounds. The diver will first play one of eight "words" coined by the researchers to see if the dolphins mimic them; then they'll listen to the dolphin sounds in hopes of sussing out salient features that could be "fundamental units" of dolphin language. It's a captivating idea, but it's also a steep challenge, Herzing concedes. "We don't even know if dolphins have words," she says. "We could use their signals, if we knew them. We just don't."
Climate change is a complicated, confusing problem, often seeming to mask its long-term risks with a smattering of short-term benefits. The Science Times highlights this confusion today with a look at Adelie penguins in Antarctica, some of which are dying due to global warming, and some of which are apparently thriving. Adelie populations on the Antarctic Peninsula north of the Ross Sea have declined by almost 90 percent in the past three decades, the Times reports, while related colonies in nearby Cape Royds and Cape Crozier seem to be defying climate change by growing robustly.
The Ross Sea is "penguin nirvana," according to penguin expert David Ainley, but parts of it have begun to suffer from vanishing sea ice. The Antarctic Peninsula's only colony of emperor penguins is already extinct, and its Adelie colony is in free fall. The western part of the peninsula has warmed by 10.8 degrees Fahrenheit in the past 50 years, pushing out ice-dependent penguins in favor of other species, like gentoos, that can handle the ice-free conditions. And the region's warming ocean waters have also been killing off phytoplankton that grows under ice floes, as well as the krill that eats the tiny algae. Since krill makes up roughly 90 percent of the Adelie penguins' diet, this is considered a major culprit behind their decline.
But winter sea-ice cover is actually growing in the Ross Sea, allowing the Cape Royds and Cape Crozier colonies to expand. The Royds colony grew by 10 percent annually until 2001, when a calving glacier disrupted the colony, although they've since recovered. The Crozier colony has increased by about 20 percent, and its 230,000 breeding pairs make it one of the largest known Adelie colonies. But this localized boom may be deceiving, since humans' increased fishing for toothfish — a competitor that eats the same fish penguins do — may have given these colonies an unnatural boost. "It has become difficult to separate whether the increase is due to climate change or fewer toothfish," Ainley says. "Both factors seem to be working at the same time." But much like polar bears, he adds, these penguins are too dependent on ice to truly thrive as global warming sets in. "Emperor and Adelie penguins have an obligatory association with sea ice," Ainley says. "As the sea ice goes, these species will go."
U.S. mining policy is set, a planned wildfire gets out of control, and more
Photo (Mississippi River floodwaters in Memphis on May 9): ZUMA Press
Photo (natural gas drilling rig): Pacific Northwest National Laboratory
Photo (diver with bottlenose dolphin): ZUMA Press
Photo (Adelie penguins on Antarctic Peninsula): ZUMA Press