The volcanic nature of the Campi Flegrei, or Phlegraean Fields, was known already in ancient times. In 1539 a smaller volcanic eruption formed the 403-foot-high cone of the Monte Nuovo, the new mountain. Victorian geologist Charles Lyell argued in 1830 that a magma chamber deep underground would not only explain the active volcanoes, but also a strange phenomenon he had observed. David BressanEarthquakes were recorded in the 1950s, 1970s and 1980s, followed by a measurable ground uplift. Today we know that the magma chamber of the Campi Flegrei is located at a depth of 1.8 miles below ground level.

Source: Forbes May 15, 2017 19:30 UTC