March 31, 2009 -- It's a hot, sunny day at the equator. Standing at the edge of a great salt lake, you look out across its shimmering beauty; waves lap delicately at your feet. Far in the distance mirages weld its shores -- salt flats -- to an unbroken blue sky. If a new theory is right, you are standing at ground zero of the greatest apocalypse the world has ever seen. During the end-Permian mass extinction 250 million years ago, nearly 90 percent of life on Earth was extinguished, and everything from magnetic field reversals to supervolcanoes has been invoked to explain it. But a group of researchers have an even more provocative idea for the murder weapon: poisonous gases vented from dried-up salt lakes. Their case begins with a lagoon off the Caspian Sea in Turkmenistan. Spanning 7,000 square miles, the Kara-Bogaz-Gol bay is constantly evaporating in a delicate balance with waters from the Caspian. It harbors a huge amount of salt and also emits a stream of toxic gases into the atmosphere. Related Content:
Ludwig Weissflog of the UFZ-Helmholtz Center for Environmental Research in Germany and a team of researchers measured gases coming from the Kara-Bogaz-Gol. They found large amounts of halogenated hydrocarbons (HHCs), chemicals like chloroform and trichloroethylene that are known to be poisonous and corrosive to Earth's ozone layer. Once they get into the atmosphere, the chemicals can also kill plants. Co-author Kastern Kotte of the Max Planck Institute for Chemistry said that during the end-Permian, conditions were hot and arid enough that there may have been a huge number of drying salt lakes on Earth, including Lake Zechstein, which was the size of Texas and covered much of what is now western Europe. With enough gas, plants would've died en masse. The lack of food and oxygen from decreased photosynthesis would cascade through the food chain, killing land animals and even spilling into the sea. Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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