Puneet Varma (Editor)

August 2016 Central Italy earthquake

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Origin time
  
01:36:33 UTC

Type
  
Normal

Max. intensity
  
IX (Violent)

Magnitude
  
6.2 ± 0.016 Mw

Areas affected
  
Italy

Date
  
24 August 2016

August 2016 Central Italy earthquake httpsuploadwikimediaorgwikipediacommonsthu

Depth
  
4 ± 1 km (2.49 ± 0.62 mi)

Similar
  
2009 L'Aquila earthquake, 2012 Northern Italy earth, 1997 Umbria and Marc, 1980 Irpinia earthquake, 2016 Ecuador earthquake

An earthquake, measuring 6.2 ± 0.016 on the moment magnitude scale, hit Central Italy on 24 August 2016 at 03:36:32 CEST (01:36 UTC).

Contents

Its epicentre was close to Accumoli, with its hypocentre at a depth of 4 ± 1 km, approximately 75 km (47 mi) southeast of Perugia and 45 km (28 mi) north of L'Aquila, in an area near the borders of the Umbria, Lazio, Abruzzo and Marche regions. As of 15 November 2016, 299 people have been killed.

Background

The central Apennines is one of the most seismically active areas in Italy. The Apennines mountain belt were formed in the Miocene to Pliocene as a result of the ongoing subduction of the Adriatic Plate beneath the Eurasian Plate, forming a fold and thrust belt. During the Quaternary, thrust tectonics gave way to extensional tectonics, with the development of a zone of normal faulting running along the crest of the mountain range. The extension is a result of either subduction rollback or the opening of the Tyrrhenian Sea. In the Central Apennines the zone of extension is about 30 km wide, closely matching the zone of observed extensional strain as shown by GPS measurements. Recent large earthquakes in this area have been caused by movement on SW-dipping normal faults.

This was the largest tremor since 2009, when an earthquake near L'Aquila in the Abruzzo region killed over 300 people and displaced about 65,000.

Earthquake

The earthquake was initially reported by INGV to have occurred at a depth of approximately 5 km (3.1 mi), with a magnitude of 6.0 Mw and epicentre in the comune of Accumoli. The USGS first reported an earthquake at a depth of 10.0 km (6.2 mi) with a magnitude of 6.4 Mw and epicentre southeast of Norcia, but subsequently revised the magnitude to 6.2 Mw. The European-Mediterranean Seismological Centre put the magnitude at 6.1. The discrepancies between the different estimates of the magnitude led INGV to explain in a blog post that they use a crustal velocity model specifically calibrated for Italy and give more weight to the seismometric stations situated close to the epicentre. Using global models, INGV further stated that it can reproduce the values reported by foreign agencies.

As of 30 August 2016, the initial earthquake was followed by at least 2,500 aftershocks. The tremor and a number of aftershocks were felt across the whole of central Italy (from Rimini to Naples), including Rome, Florence and Bologna.

Casualties and rescue work

As of 26 August 2016, the official figures of the Protezione Civile report that the earthquake caused the death of 297 people: 234 in Amatrice, 11 in Accumoli and 49 in Arquata del Tronto. At least 365 injured had to be treated in hospitals, mainly in Rieti and Ascoli Piceno, while people with less serious injuries were treated on the spot.

In addition to those rescued with the help of other inhabitants or escaped by themselves, 238 people were pulled alive from the rubble by the timely intervention of the authorities, 215 by the Vigili del Fuoco and 23 by the Soccorso Alpino.

Approximately 2,100 people found shelter in the emergency camps. Approximately 4,400 people were involved in the search and rescue operations, including 70 teams with rescue dogs. Logistics made use of 12 helicopters, with 9 more in stand-by.

The earthquake killed 276 Italians, 11 Romanians, and several others. The complete list is seen to the right.

Damage

Early reports indicated severe damage in the town of Amatrice, near the epicentre, and in Accumoli and Pescara del Tronto. Sergio Pirozzi, the mayor of Amatrice, stated that "Amatrice is not here anymore, half of the town is destroyed." Photos of the destruction depicted a massive pile of rubble in the town's centre with only a few structures still standing on the outskirts. It also cost an estimated economic loss between $1 billion to $11 billion.

Cultural heritage

In addition to the loss of human life, widespread destruction of cultural heritage is also reported.

In Amatrice, the facade and rose window of the Church of Sant'Agostino were destroyed, and the museum dedicated to the painter Nicola Filotesio, student and companion of Raphael, collapsed. The earthquake also created cracks in the Baths of Caracalla in Rome. The earthquake was so broad that authorities made structural tests on the Colosseum as well, which was not damaged.

The Basilica of Saint Francis of Assisi – a UNESCO World Heritage site with frescoes by Giotto and Cimabue that were partly destroyed by an earthquake in 1997 – was declared safe after an extensive survey by the head restorer.

Controversies

After the earthquake in Central Italy, the court of Rieti discovered that not all the buildings of those cities were constructed or renovated under the antiseismic law of 1974 in which it explained all the construction techniques of an earthquake resistant building. In fact, a family was killed that night by the rubble of a church that was not renovated under that law. Similarly, Romolo Capranica, an elementary school in Amatrice was leveled; which was shocking because only in 2013 did Amatrice spend 700,000 euros in renovation efforts that were supposedly making the school compliant with 2012 earthquake standards in Italy. Investigation into the seismic code and permits obtained for the school show that compliance with the anti-seismic measures were faked, most likely by the Italian mafia who have in the past sought after construction efforts after an earthquake. The investigation is ongoing to discover the causes that allowed buildings to become reduced to rubble instead of sustaining damage attributed to buildings following anti-seismic regulations, especially Amatrice. It is widely suspected that the Mafia obtained a large number of building permits for work that was never done all in an effort to profit without following through with the work.

French satirical magazine Charlie Hebdo published a cartoon depicting Italian earthquake victims as pasta dishes, causing "shock and outrage."

October 2016 and January 2017 earthquakes

A magnitude 6.1 intraplate earthquake struck Italy 3 kilometres (1.9 mi) west of Visso on 26 October at 9:18 p.m. local time. The earthquake, initially considered an aftershock of the magnitude 6.2 earthquake in August, struck about 30 kilometres (19 mi) to the northwest of the August earthquake. The civil protection, however, estimated the consequences less dramatically than feared. According to official data, a man died because he had suffered a heart attack as a result of the quake. On 30 October, an earthquake larger than the 24 August shock struck Norcia with a USGS moment magnitude of 6.6.

A magnitude 5.3 earthquake struck 25 km northwest of L’Aquila on 18 January at 10:25 local time at a depth of 9 km. A stronger, 5.7 tremor hit the same epicentral area at 11:14 local time. A third earthquake of preliminary magnitude of 5.6 struck 11 minutes later. At 14:33 local time, the fourth tremor of a magnitude 5.2 was registered. These earthquakes were followed by multiple aftershocks.

Earthquakes from August 2016 to January 2017.

Maps

Aftershock distribution map, 24–25 August.
Red: Main shock, Orange: 4.0–5.9, Blue: 3.0–3.9, Light blue: 0-2.9

References

August 2016 Central Italy earthquake Wikipedia