12/13/2023 0 Comments Recent volcano eruption in alaskaIn North America, we know this as the White River Ash, which erupted from Bona-Churchill massif in Alaska. Using the ages of the eruptions was no help as they both occurred at approximately the same time. It presented us with a puzzle: we had found a chemical match between an ash layer from Alaska and a layer which occurs throughout Europe, which was always presumed to come from Iceland. The majority of the dozen or so ash layers we found during this study were from well-known eruptions in North American volcanic regions such as the Aleutian Islands off Alaska or the Cascade Mountains near Portland.ĭigging for Alaskan ash in an Irish bog. They are very precise time markers in the sediment because they are deposited over a very short period of time (days to weeks). When an ash layer is identified, it provides a means of joining and aligning the environmental histories of different areas where it occurs. These “fingerprints” can then be compared with samples from elsewhere. We found a number of ash layers throughout the sediments covering the past several thousand years.īy analysing the elements in the ash’s glass particles we are able to obtain a chemical “fingerprint” unique to that ash layer. Volcanic ash flies long haulĪ few years ago we were involved in a project to reconstruct past environmental changes along North America’s east coast. The industry was lucky to evolve in what was a relatively quiet period between major ash producing eruptions in Iceland. The Icelandic volcanoes Katla and Hekla, for example, produced large ash plumes in 19, but both were modest by comparison with the massive Asjka eruption of 1875 which blanketed much of Scandinavia in ash. Looking back through history one can see that 2010 was by no means unique. Perhaps there is a failure to appreciate that volcanic eruptions often occur in cycles with busy periods followed by intervals of relative quiet during which time these events pass out of social memory. Given volcanoes erupt all the time it seems odd that the Iceland incident came as such a shock. In fact, the ash has barely settled from Alaska’s latest major eruption. We need to be wary as another major ash cloud could arrive at any time. New evidence shows such ash clouds are more common than we thought, and they can even cross the Atlantic from volcanic hot-spots in North America. A huge ash cloud grounded more than 100,000 flights and delayed 10m passengers, costing the aviation industry more than £2 billion. A volcanic eruption in Iceland caused massive disruption throughout Europe in 2010.
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