Italy already has some of themost grievous volcanoesin the creation as it is , but until late , Rome was thought to be relatively good from all but the most massive of eruption . Now , a young bailiwick inGeophysical Research Letterssuggests this may no longer be the case . Colli Albani ( “ Alban Hills ” ) , a volcanic complex just 20 kilometer ( 12 miles ) southeast of Rome and long thought to be extinct , is rumble back to life .
The squad behind this study have for over a decennary suggested that Colli Albanishouldn’t be reckon extinctat all , but dormant – building up to a new irruption . They point out , for example , that over the last 200,000 years , the ground has rise about 50 meters ( 164 feet ) , which suggests that magma has beenslowly poolingbeneath the priming coat .
In addition , they highlight a serial publication of 1990s quake ( perhaps magma coerce its manner up through the crust ) , the organisation of a new steam venthole , sudden carbon dioxide outbursts , and the fact that the ground is still rising by about 2 mm ( 0.08 inch ) every yr as clear evidence of an at hand bam .
“ The precursors of a new phase of volcanic action are likely occurring at the [ vent ] , ” the researchers , led by the Italy - base National Institute of Geophysics and Volcanology , write in their study .
The key question , then , is when exactlywill it conflagrate next ?
Although they only have a low sample distribution size – the geologic platter for this vent is quite patchy – they note that the volcano tends to becomeactiveevery 38,000 years or so , with each major eruption occurring every 41,000 years . The last important bang was 36,000 years ago , which seems to suggest that another is n’t due for 2,000 years at least .
However , the team argues that if you front at the last 100,000 years of bodily process , the major eruption recurrence interval can be gauge down to one every 31,000 years . In this casing , an eruption is 5,000 years overdue , and the squad suggest that the next will likely happen in the next 1,000 years or so .
An autumnal Rome . Is this volcanic coordination compound about to put down it ? Credit : Robin Andrews
But – and this is the key piece of information – the account of thevolcanosuggests that when this bam does occur , it wo n’t destroy Rome after all .
Just under 610,000 years ago , acaldera(“cauldron ” ) was forge in the area when a vast rupture in a sizeable magma sleeping accommodation forced its contents rapidly and violently out onto the surface , and the overlying rock jacket sank down into the world .
Between then and 351,000 years ago , it produced280 three-dimensional kilometers(67 cubic miles ) of volcanic matter – more than enough to surround any major urban center . After this more explosive period , it became more or less calmer , producingprolonged lava flowsand launch the occasional gas - fueled biff of lava out of the primary vent , much like the famous Mount Etna does today .
After this phase , its most geologically recent activity has been to bring forth small pit craters called “ maars ” that form when water and magma mixing beneath the footing . This style of eruption is known as phreatomagmatic , and is thought to only occur when water system is immobilise within the magma before expound rapidly and explosively .
This means that the bang intensity has been in declination for over half a million age , and unless something major changes beneath the site , it ’s likely any subsequent eruption , although newsworthy , probably wo n’t eradicate the Italian majuscule .
Phew . No doom for Rome . rweisswald / Shutterstock
