Italiano Vesuvio
...Mount Vesuvius. The caldera of Vesuvius was formed approximately 14,000 years ago. Vesuvius is a complex volcano, which, according to Peter Fancis, is “an extensive assemblage of spatially, temporally, and genetically related major and minor [volcanic] centers with their associated lava flows and pyroclastic flows.” Vesuvius erupted about every 100 years until approximately 1037 AD, where it was quiescent, or dormant, for a 600-year period, and until the eruption in 79 AD, it had been quiescent for approximately ten centuries, which is uncommon among young volcanoes. In 1631, Vesuvius once again became active, and entered into a period that had only two distinctive stages: quiescent, where the mouth would be obstructed, and eruptive, where the mouth would remain almost continually open. The eruptive stages have varied from 6 months to 30.75 years and the quiescent stages have varied from 18 months to 7.5 years until 1944, where it has remained quiescent up to now. Until quiescence in 1944, Vesuvius was considered continually active, erupting on an average of every 15 years, where, previous to 1037, it erupted an average of every 104 years. Eruptions are characterized by a series of massive earthquakes, estimated to range anywhere from 2.1 to 7.9 on the Richter scale, that occur anywhere from about 8 months to 15 years and gradually increase in magnitude for about six months at a time prior to a massive, super-plinian eruption. Generally, the eruptive cycle begins and ends with a “catastrophic” eruption. Pliny the Younger witnessed the eruption in 79 AD from a point 30 km west of the volcano, and described much of what we know today about it in two letters. It is estimated that at times during the eruption the column of ash was 32 km tall and about 4 cubic kilometers of ash was erupted in about 19 hours. About 3 meters of tephra, materials of all types and sizes that are erupted from a crater or volcanic vent and deposited from the air, fell on Pompeii and Stabiae over the c...