Sectors Italy Mapped.

A labyrinth of subterranean passages that date back to the founding of Rome are being mapped to predict which modern buildings could be at risk of suddenly disappearing into a Roman quarry system.
While this may seem unlikely, a staggering 83 structures have already collapsed due to the underground network of passages this year alone, ranging from buildings to streets. A labyrinth of passages (pictured) that date back to the founding of Rome are being mapped to predict which modern buildings are at risk of suddenly disappearing into a Roman quarry system. A team of geologists from George Mason University, Washington and the Centre for Speleoarchaeological Research, Sotterranei di Roma, are exploring the underground network to produce a detailed map that can be used to assess areas of the city that are most at risk. Geologist Giuseppina Kysar Mattietti from the university told true history, that the mapping activity is critical as over the years locals have been patching up holes that have suddenly appeared.The geoscientists are using 3D laser scanning to look for weaknesses in known tunnels, before entering them through manholes to map the network, once they know they are safe.‘There might be cracks, so they will be showing as veins almost, or openings, so we map the openings and map any kind of detachment,’ she said. The team has come across weakened ceilings as well as blockages and collapses that are alarmingly close to street level.

This map shows the expansion of Rome (from its centre marked as 1) over the ancient quarry system, which is most comprehensive in the south east of the city, where dark green lines can be seen. For the mapping procedure geoscientists are using 3D laser scanning to look for weaknesses in known tunnels.
Any cracks show up as 'veins' or openings on the scanning results. Labyrinth of ancient Roman tunnels is mapped to stop ‘Italy's capital collapsing into an underground void’. Geologists from George Mason University, Washington and the Centre for Speleoarchaeological Research in Rome are exploring the Roman network. Starting in the south east of the city, they are producing a detailed map of the quarries that will be used to assess areas of Rome that are most at risk. The narrow tunnel-like quarries were dug by the Romans so they could use volcanic rock to build the city but the channels have since been widened. While tourists might be preoccupied with snapping Roman landmarks in Italy’s capital city, beneath the streets geologists are documenting equally ancient tunnels. If a tunnel is found to be safe, the geologists enter it through manholes. They can then explore the tunnel and extend their map of the underground network. The tunnels were originally created to provide building material for the rapidly growing city. Rome is built on volcanic rock which is strong but easy to carve and was therefore of interest to Roman builders and architects, who also made use of less compacted volcanic material to produce mortar for their buildings.

The first Romans dug into the rock outside the city but as Rome grew to fill the areas previously used as quarries, they knew they could still use the tunnels for rock, providing they kept them narrow so buildings above ground could still be supported, Dr Mattietti explained.However, over time, weathering and humans have widened the tunnels – the latter by taking more rock from the tunnels for new buildings. Here, people stand on a Roman street, which is over 15 ft (5m) below modern street level and was built in the second century AD. Dr Mattietti described underground ancient Rome as 'a double reality' Holes are opening up all over the city of Rome and weathering plus humans widening the tunnel-like quarries have been blamed. This one is collapsed. Some locals have taken the repair of such holes into their own hands. The tunnels have also been exploited for mushroom farming, ad-hoc sewer systems, catacombs and bomb shelters during World War II. Dr Mattietti said that quite a lot of ancient Rome that is now below street level that was not to start with and described the phenomenon as a 'double reality’. ‘It's interesting, because at times when you are down there, you can hear people on top,’ she said. The team, whose work so far has been presented at the annual meeting of the Geological Society of America, began the study in the south eastern area of Rome, which has most quarries.