Earthquake-induced apocalypse in Central Italy

Central-Southern Italy is, once again, in the news for what will be remembered for decades as a domino-effect disaster that has wiped out a luxury resort on the late afternoon of January 18.

On that day, the Italian Institute for Geophysics and Volcanology (INGV) recorded about 200 seismic events, all of which with M > 2. Four of these events were stronger than M = 5, reaching M = 5.4. The two areas that were hit are the same affected by the two deadly temblors of 2009 and 2016, i.e. the L’Aquila province and the Rieti province, respectively in the Abruzzo and the Lazio regions.

The cluster of epicenters recorded and localized by the Italian Seismic Network, appear to delineate a 5-km-wide and 10-15-km long area that is trending NW-SE, the same direction as the Appenine Chain. The fault that triggered the shocks belong to the system known to Italian geologists as Mt. Laga Fault System.

Central Italy (1)
Cluster of epicenters, aligned NNW-SSE, of all events with M>4 in Central Italy from 2009 onward. Yellow stars are epicenters of quakes with M > 5. Data elaborated by Fabio L. Bonali from the database available at http://earthquake.usgs.gov/earthquakes.

The tremors have not directly claimed lives, but they have, most likely, triggered a chain reaction culminating in a tragedy that is, so far, unprecedented in Italy. In the province of Pescara, in a pristine mountain site at about 1200 m asl along the southeastern foothills of the Gran Sasso, the charming, secluded Rigopiano luxury resort  and SPA has been swept away, with terrible force, by a huge snow avalanche that rushed down from a nearby mountain top. The avalanche has hit the resort with strength of 4000 trucks, burying it underneath 50,000 tons of snow, earth, trunks and branches. It is feared that, when rescuers will have finished digging through the remains of the hotel, the disaster will have claimed 30 lives.

Rigopiano 1

In Italy, controversies are fueling the debate over why a mountain resort was left open after an unprecented snowfall that had accumulated more than 2 meters of snow in the area. Tragedy was just a matter of days, maybe hours, even without a seismic trigger; but it was likely the shaking induced by the quakes in the nearby L’Aquila province, a few hoursd before, that gave the final push to the deadly avalanche.  

Preliminary analysis of the trees unrooted by the avalanche reveals most may have been 150 years old. That means events of this scale have not affected the area since at least 1870; it is no secret that the recurring intervals of catastrophies, as often is the case with geological and climate-related events, much longer than our lifespan.  It is difficult to envision the possibility of disasters when there is no “historical memory” like avalanches.

Many are questioning, these days, the reasons why a resort was built in an area that was prone to disaster. There are so many places, across the Italian peninsula, from North to South, where buildings and infrastructures have been built in areas prone to earthquakes, volcanic eruptions, debris avalanches, mudflows, snow avalanches, floods.

Italy is such a densely popuated country, with 58 million people living in a geologically young and fragile geological territory, that more disasters are to be reckoned with in the future. Climate change is taking its toll on our vulnerable land. Relentless geological forces are stretching the peninsula as it drifts inexorably towards the Balcans.

Earthquakes have always been the norm in Italy, for millions of years, and will always be. The country has a long history of civilization and, as reported in the online catalogue of strong earthquakes in Italy, quakes have been reported in Central Italy since the first Century B.C. As a matter of fact, the earliest historical reports date back to 99 B.C., when a tremor with Macroseismic Intensity equal to 9 struck the ancient town of Norcia, that was regularly shattered by temblors ever since.

Italy is at a crossroads: Either we understand that we need to join forces to strengthen our surveillance across the whole peninsula, from Lombardy to Sicily, or we will have to get used to mourn the dead and pay the billions of euros needed to rebuild our houses, towns, roads.

Federico Pasquaré Mariotto (Associate Professor, Insubria University, Varese, Italy)                                                                                                   Fabio L. Bonali (Researcher, Milan-Bicocca University, Milan, Italy)