A waking volcano on the outskirts of Rome has the potential to erupt as violently as Mt. Vesuvius, the volcano that destroyed Pompeii. That's not likely to happen in the immediate future, but volcanologists are nevertheless keeping a watchful eye on recent rumblings of the Alban Hills in Italy.

Pompeii vanished under a plume of volcanic ash followed by fiery pyroclastic flows in 79 AD. Since that time, Mt. Vesuvius has erupted many times, most recently in 1944, though not to such a devastating degree again. Vesuvius is currently the only active volcano found in mainland Europe.

Colli Albani (Alban Hills) is the name for a cluster of hills that lies 12 miles (24 km) to the southeast of Rome. Although known to be the site of a volcanic complex, Colli Albani has not ever had an eruption in human history. The last time it erupted was 36,000 years ago.

Colli Albani was therefore thought to be an extinct volcano until recently. Scientists have started to detect tectonic movement and new steam vent formation in the area, reports the GeoSpace blog. The landscape around Colli Albani has been found to be rising slowly, pushed up by pressure exerted by a huge magma "bubble" deep in the earth.

In addition, scientists have collected new geophysical evidence of past eruptions and gathered information from satellite observations. The researchers have published their findings in Geophysical Research Letters, offering the conclusion that Colli Albani is entering into a new eruptive cycle and is likely to erupt one day.

Fortunately, that day is 1,000 years in the future, by the volcanologists' reckoning. But when it does happen, it will probably be a massive explosion.

The eruption will send immense clouds of fiery ash and smoke far out the countryside. Rocks will be hurled down on nearby cities, including Rome, whose metropolitan center is presently 19 miles (30 km) away from Colli Albani. So far, the main effect of the Colli Albani awakening has been a series of small earthquakes that lightly rocked Rome from 1991 to 1995, according to LiveScience.