On December 5, the largest earthquake to occur on the Italian Peninsula struck the

Kingdom of Naples The Kingdom of Naples ( la, Regnum Neapolitanum; it, Regno di Napoli; nap, Regno 'e Napule), also known as the Kingdom of Sicily, was a state that ruled the part of the Italian Peninsula south of the Papal States between 1282 and 1816. It was ...

. The earthquake had an estimated

moment magnitude The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...

of 7.19–7.4 , and nucleated near the town of Pontelandolfo in present-day

Province of Benevento The Province of Benevento ( it, Provincia di Benevento) is a province in the Campania region of Italy. Its capital is the city of Benevento. Geography The province has an area of 2,071 km2, and, , a total population of 279,308. There are 78 ...

, central Italy. Earning a level of XI (''Extreme'') on the

Modified Mercalli intensity scale The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

, the earthquake caused widespread destruction in central and southern Italy. An estimated 30,000–70,000 people were killed. It was followed by two strong 7.0 and 6.0 earthquakes to the north on December 30.

Tectonic setting

The central Italian Peninsula is dominated by active

extensional tectonics Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere. Deformation styles The types of structure and the geometries formed depend on ...

, forming the

Apennine Mountains The Apennines or Apennine Mountains (; grc-gre, links=no, Ἀπέννινα ὄρη or Ἀπέννινον ὄρος; la, Appenninus or – a singular with plural meaning;''Apenninus'' (Greek or ) has the form of an adjective, which wou ...

. The mountain range formed during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

of the

Adriatic Plate The Adriatic or Apulian Plate is a small tectonic plate carrying primarily continental crust that broke away from the African Plate along a large transform fault in the Cretaceous period. The name Adriatic Plate is usually used when referring ...

beneath the

Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...

. The resulting subduction formed a

fold and thrust belt A fold and thrust belt (FTB) is a series of mountainous foothills adjacent to an orogenic belt, which forms due to contractional tectonics. Fold and thrust belts commonly form in the forelands adjacent to major orogens as deformation propagates ou ...

. During the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

thrust tectonics Thrust tectonics or contractional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the shortening and thickening of the crust or lithosphere. It is one of the three main types of tectonic regime, ...

gave way to

, with the development of a zone of normal faulting running along the crest of the mountain range. One explanation is that slab rollback is occurring within the

as it subducts beneath the

Tyrrhenian Sea The Tyrrhenian Sea (; it, Mar Tirreno , french: Mer Tyrrhénienne , sc, Mare Tirrenu, co, Mari Tirrenu, scn, Mari Tirrenu, nap, Mare Tirreno) is part of the Mediterranean Sea off the western coast of Italy. It is named for the Tyrrhenian pe ...

. Another explanation is because the

back-arc basin A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of ...

in the

is opening at a faster rate than the

African Plate The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plat ...

is colliding with the

. Extensional tectonics in the region have been active since the since the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

, mainly accommodated by northwest–southeast striking

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s. The faults associated with large earthquakes on the peninsula are geologically young in age, and rarely rupture the surface. Occasionally, strike-slip events like the 1456 sequence, as well as the 1971 ( 5.0) and 2012 ( 4.6) moderate earthquakes in the southern Apennine region suggest the dominant style of faulting is not limited to normal dip-slip.

Earthquakes

December 5

The shock of December 5 was estimated at 7.19 ± 0.1 by the 2014 version of the

National Institute of Geophysics and Volcanology The National Institute of Geophysics and Volcanology ( it, Istituto Nazionale di Geofisica e Vulcanologia, INGV) is a research institute for geophysics and volcanology in Italy. INGV is funded by the Italian Ministry of Education, Universities and ...

earthquake catalog. Its magnitude has been estimated to be as high as 7.4. Based on studying the macroseismic effects of the event, three distinct subevents separated by several seconds were discovered. The earthquake occurred in a region of active crustal movement along east–west striking

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s. The rupture process involved a complex cascade of independent faults rupturing subsequentially; as many as five subevents constituated the mainshock. The

earthquake rupture In seismology, an earthquake rupture is the extent of slip that occurs during an earthquake in the Earth's crust. Earthquakes occur for many reasons that include: landslides, movement of magma in a volcano, the formation of a new fault, or, mos ...

extended from

Abruzzo Abruzzo (, , ; nap, label=Neapolitan language, Abruzzese Neapolitan, Abbrùzze , ''Abbrìzze'' or ''Abbrèzze'' ; nap, label=Sabino dialect, Aquilano, Abbrùzzu; #History, historically Abruzzi) is a Regions of Italy, region of Southern Italy wi ...

Irpinia Irpinia (Modern Latin ''Hirpinia'') is a geographical and cultural region of Southern Italy. It was the inland territory of the ancient ''Hirpini'' tribe, and its extent matches approximately today's province of Avellino. Geography The territor ...

. Northwest-southeast trending normal faults are thought to be the source of the quake. Unlike most earthquakes in the area with rupture occurring in the shallow 12 km of the crust, the source of the 1456 earthquake was between 12 and 25 km beneath. The 1456 earthquake subsequentlly triggered future earthquakes nearby due to the behavior of faults in the area. Another hypothesis suggest the earthquakes were strike-slip events that occurred at a depth of 10–25 km. The December 5 event occurred along a west-northwest-east-southeast striking oblique right-lateral fault. It ruptured east of the fault that caused the earthquake of 1688.

December 30

Another similar fault located further north, in

Matese The Matese (Italian: Monti del Matese or Massiccio del Matese) is a chain of mountains in southern Apennines, southern Italy. Geography The Matese mountains straddle two regions (Molise and Campania) and four provinces (Campobasso, Isernia, Ben ...

generated the shock of December 30. Many large

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...

s accompanied the earthquake on December 5. Intensity X–XI was felt in a northwest-southeast trending configuration from Macchiagodena to Castelluccio Acquaborrana. It was also felt in an east-west area from Boiano to Cercemaggiore. The widespread distribution of great intensity and its similarities with the December 5 event suggest the December 30 quake occurred at a deeper depth (>10 km). Based on evaluating the reported intensities of the December 30 event, its magnitude is no greater than 7.2. A third shock was recorded in the area affected by the December 30 event. This earthquake was felt VIII–IX over a wide area as well, suggesting a deep focal origin. A moment magnitude of 6.0 was estimated.

Effects

Intensity

Complete destruction occurred in a zone measuring 6,000 km². Whereas the total area affected was 18,000 km². The area of devastation was unusually large compared to most earthquakes in Italy; thought to be caused by the occurrence of multiple ruptures. The

meizoseismal area The meizoseismal area in an earthquake is the area of maximum damage. For example, in the Charleston, South Carolina, earthquake of 1886, the meizoseismal area was an area about twenty by thirty miles stretching northeast between Charleston and ...

stretched for nearly 180 km, assigned X–XI (''Extreme''), where destruction of structures occurred. The unusually large area of the meizoseismal area is caused by multiple faults, separated by significant distances rupturing. The commune of Caramanico Terme experienced a maximum intensity of XI. Intensity IX–X was felt in the towns of

Tocco da Casauria Tocco da Casauria is a ''comune'' and town in the Province of Pescara in the Abruzzo region of Central Italy. The centre was known for centuries as simply Tocco, and the name "da Casauria" was added only after 1861. It rises on a hill between the ...

, Torre de' Passeri and

Castiglione a Casauria Castiglione a Casauria is a ''comune'' and town in the province of Pescara in the Abruzzo region of Italy. It is located in the natural park known as the "Gran Sasso e Monti della Laga National Park". Main sights *The Abbey of San Clemente a Casau ...

. From the lower Aterno Valley (in the north), to

Sulmona Sulmona ( nap, label= Abruzzese, Sulmóne; la, Sulmo; grc, Σουλμῶν, Soulmôn) is a city and ''comune'' of the province of L'Aquila in Abruzzo, Italy. It is located in the Valle Peligna, a plain once occupied by a lake that disappeared in ...

, and

Navelli Navelli is a ''comune'' and town in the province of L'Aquila, in the Abruzzo region of central Italy. It is renowned for the local saffron production. Navelli and its ''frazione'' (hamlet) Civitaretenga are medieval villages located in a territory ...

(in the southeast), the intensity was VIII–IX. Intensity VIII–IX was felt over an area that was 40 km wide. About 20 km away, the intensity gradually fell to V.

Tsunami

A series of anomalous waves in the

port of Naples The Port of Naples, a port located on the Western coast of Italy, is the 11th largest seaport in Italy having an annual traffic capacity of around 25 million tons of cargo and 500,000 TEU's. It is also serves as a tourist hub, servicing an estima ...

also caused boats to crash. There was also reports of a tsunami in the

Gulf of Taranto The Gulf of Taranto ( it, Golfo di Taranto; Tarantino: ; la, Sinus Tarentinus) is a gulf of the Ionian Sea, in Southern Italy. The Gulf of Taranto is almost square, long and wide, making it the largest gulf in Italy, and it is delimited by the ...

, where it struck the Ionian coastline.

Impact

The December 5 shock struck at 11:00 pm

local time Local time is the time observed in a specific locality. There is no canonical definition. Originally it was mean solar time, but since the introduction of time zones it is generally the time as determined by the time zone in effect, with daylight s ...

, lasting approximately 150 seconds. Devastation was reported in five of the 20 regions of Italy;

Molise Molise (, , ; nap, label=Neapolitan language, Neapolitan, Mulise) is a Regions of Italy, region of Southern Italy. Until 1963, it formed part of the region of Abruzzi e Molise, alongside the region of Abruzzo. The split, which did not become effe ...

Campania Campania (, also , , , ) is an administrative Regions of Italy, region of Italy; most of it is in the south-western portion of the Italian peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the i ...

Puglia it, Pugliese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographic ...

, and

Basilicata it, Lucano (man) it, Lucana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = ...

; whereas some damage occurred in

Lazio it, Laziale , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

and

Calabria , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

. The earthquake of December 30 at 9:30 pm which measured 7.0 was not as severe in

Napoli Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

. Regions closer to the epicenter reported in serious damage. Documentation of heavy destruction in Sannio and the Campana Plain might be due to conflicting reports of the previous event. Major damage occurred in Isernia. There was no damage in the areas between

Castel di Sangro Castel di Sangro (locally ''Caštiéllë'') is a city and '' comune'' of 6,461 people (as of 2013) in the Province of L'Aquila, in Abruzzo, Central Italy. It is the main city of the Alto Sangro e Altopiano delle Cinque Miglia area. Geography Ca ...

and

. Additional damage also occurred due to the aftershocks, which persisted up till early 1457. The aftershock sequence only ended in May 1457.

Casualties

As many as 70,000 people were killed in the earthquakes. In the town of

Isernia Isernia () or, in Pliny and later writers, ''Eserninus'', or in the Antonine Itinerary, ''Serni''. is a town and ''comune'' in the southern Italian region of Molise, and the capital of province of Isernia. Geography Situated on a rocky crest ...

, catastrophic damage occurred; 1,500 residents of the total 2,035 perished. Between 100 and 150 people died in

Naples Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

due to many homes and churches collapsing. Another 100 people died in

Pozzuoli Pozzuoli (; ; ) is a city and ''comune'' of the Metropolitan City of Naples, in the Italian region of Campania. It is the main city of the Phlegrean Peninsula. History Pozzuoli began as the Greek colony of ''Dicaearchia'' ( el, Δικα ...

. There were between 600 and 2,200 fatalities in

Apice Apice is a ''comune'' (municipality) in the Province of Benevento in the Italian region Campania, located about 70 km northeast of Naples and about 13 km east of Benevento. Apice borders the following municipalities: Ariano Irpino, Bon ...

, 2,000 in Barberio, more than 1,000 in Lafino, 400 in

Cerreto Sannita Cerreto Sannita (; nap, label=Campanian, Cerrìte ) is a ''comune'' (municipality) in the Province of Benevento in the Italian region Campania, located about 60 km northeast of Naples and about 25 km northwest of Benevento. Cerreto Sa ...

, and 1,200 in

Acerenza Acerenza ( Lucano: ) is a town and ''comune'' in the province of Potenza, in the Southern Italian region of Basilicata. History With its strategic position above sea-level, Acerenza has been sacked by a series of invaders. The town, then kno ...

Aftermath

Several villages in the affected area were abandoned.

Alfonso V of Aragon Alfonso the Magnanimous (139627 June 1458) was King of Aragon and King of Sicily (as Alfonso V) and the ruler of the Crown of Aragon from 1416 and King of Naples (as Alfonso I) from 1442 until his death. He was involved with struggles to the t ...

, the

King of Aragon This is a list of the kings and queens of Aragon. The Kingdom of Aragon was created sometime between 950 and 1035 when the County of Aragon, which had been acquired by the Kingdom of Navarre in the tenth century, was separated from Navarre in ...

, received news of the disaster while he was residing in

Apulia it, Pugliese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographic ...

. He would only return to Naples in early February 1457, where he declined tax exemption requests by survivors in the affected towns. Alfonso V stated that the survivors were able to pay taxes as they inherited the fortune of those who were killed. Reconstructions by the authorities were limited; only military fortresses, roads and bridges were supported in the interest of the military.

References

{{Earthquakes in Italy Earthquakes in Italy 1456 in Europe History of Naples Tsunamis in Italy 15th century in Italy Isernia Province of Benevento History of Lazio 15th-century earthquakes History of Calabria History of Basilicata History of Abruzzo History of Molise History of Apulia History of Campania Sulmona Tocco da Casauria