  | |
| Local date | 3 November 1706 (1706-11-03) |
|---|---|
| Local time | 13:00 (CEST) |
| Duration | 20 seconds |
| Magnitude | 6.6–6.84Mw |
| Epicenter | 42°04′34″N14°04′48″E / 42.076°N 14.080°E /42.076; 14.080[1] |
| Type | Unknown |
| Areas affected | Abruzzo,Italy |
| Max. intensity | MMI XI (Extreme) |
| Casualties | 2,400 dead |
The1706 Abruzzo earthquake, also known as theMaiella earthquake, occurred on November 3 at 13:00CEST. The earthquake with a possible epicenter in the CentralApennine Mountains (Maiella),Abruzzo had an estimated moment magnitude of 6.6–6.84 Mw .[1] It was assigned a maximumMercalli intensity of XI (Extreme),[1] causing tremendous destruction inValle Peligna. At least 2,400 people were killed.[2][3]
The centralItalian Peninsula is dominated by activeextensional tectonics, forming theApennine Mountains. The mountain range formed during theMiocene andPliocene due to thesubduction of theAdriatic Plate beneath theEurasian Plate. The resulting subduction formed afold and thrust belt. During theQuaternary,thrust tectonics gave way toextensional tectonics, with the development of a zone ofnormal faulting running along the crest of the mountain range. One possible explanation for the change in the tectonic regime is slab rollback occurring within theAdriatic Plate as it subducts beneath theTyrrhenian Sea. Another explanation is because theback-arc basin in theTyrrhenian Sea is opening at a faster rate than theAfrican Plate iscolliding with theEurasian Plate.[4] Extensional tectonics in the region is mainly accommodated by northwest–southeast strikingnormal faults.[5]
In the Central Apennines, the zone of extension is about 30 km wide, closely matching the zone of observed extensional strain as shown byGPS measurements. Recent large earthquakes in this area have been caused by movement on southwest-dipping normal faults.[4] Theregion has seen very destructive earthquakes in its history, including an Mw 6.6 in the2nd century AD, 1706, 1915, 1933, and 2009.[6]
The earthquake was associated with shallow crustal faulting within the extensional zone on the Italian Peninsula, nearMaiellamassif. This part of the tectonic zone represents the outermostanticline of the Central Apennines fold and thrust belt. Thrusting resulted in uplift and formation of the massif until the late Pliocene, when extension became dominant. The Caramanico Fault, a 30-km-long normal fault, runs the western base of the massif. Two other faults; the Palena and Porrara faults are situated at the southwestern part of the massif.[7]
The source mechanism of faulting is debated between normal or thrust faulting. A known fault commonly associated with the earthquake is the Porrara Fault; a 20-km-long, west northwest–east southeast trending normal fault located at the southwestern portion ofMaiellamassif (Monte Porrara). Thefault scarp associated with the Porrara Fault is visible for 3 km.[7] However, modelling of the earthquake using its geological and seismic intensity information suggest rupture on a southwest dippingthrust fault at a shallow depth of 5–10 km.[8]
The 1706 disaster occurred just three years after a series of destructive earthquakesstruck the Central Apennines. It lasted twenty seconds but caused massive destruction.[9] A second shock on the night of November 4 caused additional damage and some casualties in areas less affected by the previous one. In total, the earthquakes killed 2,400 people.[10]
The historic city ofSulmona suffered heavy damage, and more than 1,000 people died.[11] This has been inferred by the presence of many buildings, all built in the 18th and 19th centuries. The earthquake effectively destroyed much of the city's architectural heritage.[2][12] Much of the town ofAnversa degli Abruzzi was destroyed, including castles and homes. Serious damage was also reported inChieti,Lama dei Peligni,Manoppello,Palena,Cansano,Prezza,Raiano,Vittorito,Roccacasale,Salle,Tocco da Casauria,Rivisondoli,Roccaraso,Lettopalena,Lama dei Peligni, andFara San Martino. In Palena, out of a population of 450, three hundred residents perished.[10] Damage was also reported inL'Aquila. More than 100 fatalities were reported inGamberale, and the town was destroyed. Five people were killed and 120 were injured inFara San Martino. AtLama dei Peligni, the death toll was 130, while a further 120 were injured. At least sixty deaths were recorded in Lettopalena and 100 inTaranta Peligna.[13] The abbey ofSan Liberatore a Maiella and its church were damaged, but restored successfully.[14]
Damage was also reported in the regions ofLazio,Molise, andApulia. InCassino andSora, Lazio, and the wider Apulian region, plaster on buildings fell. It also fell off theMonte Cassino abbey. Many towns in Molise suffered minor to extensive damage, but no human casualties were reported.[14]
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