Science of dating events using ice updating p1i


Noncommercial ‒ you may not use this work for commercial purpose.No Derivative works ‒ You may not alter, transform, or build upon this work.Less than two years later, as the graph indicates, scientists detected Chernobyl radioactivity in snow at the South Pole--a graphic reminder of how small our planet is. Distinct annual layers stand out because, in snow that falls in summer, crystals are larger and acidity higher than in winter snow. (This represents about 11,350 feet of ice accumulation.) The graph clearly shows how a rise in gases will mean a rise in global temperature (though whether rising gases trigger rising temperatures, or vice versa, remains unknown).

science of dating events using ice-39science of dating events using ice-55

Using cosmogenic isotopic analyses of less than two dozen samples, Mackintosh et al. 551–554]) lift the veil of suspicion that has hung over the East Antarctic Ice Sheet.Indeed, fallout from the Chernobyl nuclear accident has turned up in ice cores, as has dust from violent desert storms countless millennia ago. If an eruption on the order of Toba, which climatologists believe may have led to as much as several centuries of cold climatic conditions, were to occur today, it could seriously disrupt life on Earth. Collectively, these frozen archives give scientists unprecedented views of global climate over the eons. Many scientists fear that rising levels of so-called "greenhouse gases" from the burning of fossil fuels and other human activities will cause global warming, with potentially grave consequences for human agriculture and society. They have also identified a spike representing fallout from stepped-up atmospheric testing that took place just prior to the 1963 Test Ban Treaty, which allowed for underground tests only. This graph, which combines results from cores taken in both Antarctica and Greenland, tracks sodium levels over the past 1,200 years. (Winds are generally stronger in springtime, meaning more dust gets blown into the atmosphere.) In this photograph of an ice core drilled in the Kunlun Mountains of western China, the thick, lighter bands indicate heavy snowfall during the monsoon season in the year 1167 AD, while the thinner, darker strips show layers of dust blown into the snowfield during the dry season. Sporadic solar energetic particle (SEP) events affect the Earth’s atmosphere and environment, in particular leading to depletion of the protective ozone layer in the Earth’s atmosphere, and pose potential technological and even life hazards.No longer should it be considered a major player in postglacial sea-level rise.

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