UTC time | 1905-09-08 01:43:02 |
---|---|
ISC event | 16957871 |
USGS-ANSS | ComCat |
Local date | 8 September 1905 |
Local time | 02:43 |
Magnitude | 7.2 Mw [1] |
Depth | 15 km (9 mi) [1] |
Epicenter | 38°38′N15°47′E / 38.64°N 15.78°E [1] |
Max. intensity | MMI XI (Extreme) [2] |
Tsunami | 1.3 m (4 ft 3 in) [3] |
Casualties | 557–2,500 dead [3] [4] |
Striking southern Italy on 8 September, the 1905 Calabria earthquake had a moment magnitude of 7.2 and a maximum Mercalli intensity of XI (Extreme). The first major earthquake of the 20th century, it severely damaged parts of Lipari, Messina Province and a large area between Cosenza and Nicotera and killed between 557 and 2,500 people.
The region of Calabria is located between the Tyrrhenian and Ionian Seas, where active extension is ongoing as a result of slab rollback affecting Tethyan oceanic crust of the African plate as it subducts beneath the Eurasian plate. The initial result of the rollback was the formation of the Tyrrhenian Sea back-arc basin starting in the Miocene, continuing in to the Pleistocene. The location of the extension migrated eastwards overall, progressively affecting areas previously affected by thrusting. [5] Extension is accommodated by normal faults on the Tyrrhenian side in Calabria. Many of the active rift faults border basins containing Pliocene–Pleistocene sedimentary sequences. [6] The trend of normal faults extend southwards to the Strait of Messina, where they occur on the Ionian side in Sicily. Known as the Siculo-Calabrian rift, this active geological feature is characterized by its high seismicity of earthquakes up to Mw 7.1. A series of major damaging earthquakes associated with this rift zone began in 1638, with a sequence of four events, followed by those in 1659, 1693, five earthquakes in 1783, 1905 and 1908. Together these earthquakes ruptured almost the entire length of the zone. [7]
The earthquake was felt strongly over a wide area including Basilicata, Irpinia, Salerno and Catania. It was felt as far away as western Albania, Isernia and Palermo. The maximum felt intensity was estimated to be X (Ruinous) on the MCS scale. [8]
The mainshock was preceded by two small foreshocks at 23:00 on 7 September and at 0:40 on 8 September. The mainshock occurred at 01:43 UTC and was followed immediately by two aftershocks. The magnitude of the mainshock has been given a wide range of values, from 6.7 Me (equivalent magnitude from intensity observations by INGV), [8] to 7.41±0.29 Mw from instrumental observations. [9] The ISC GEM catalogue gives the event as 7.2 Mw , [1] while an estimate from a mapped fault in the Sant'Eufemia Gulf, based on a slip value of 2.3 m, gives 6.9 Mw . [10] A recalculation of instrumental recordings using seven stations, rather than the analysis of the records from two stations that gave the higher 7.41 value, gave a magnitude of Mw 7.10±0.26, closer to other estimates. [11]
In the three months after the earthquake, there were 100 aftershocks, rising to 219 by the end of 1905. A further 95 aftershocks were recorded in 1906 and another 82 in 1907. [8]
The location of the earthquake's epicenter and the causative fault are also debated. Three main epicentral locations have been proposed, onshore on Capo Vaticano, offshore in the Sant'Eufemia Gulf or west of Capo Vaticano. [2] The main candidate faults include the proposed Capo Vaticano Fault, thought to be part of the main NW-dipping set and trending SW-NE just offshore from the cape. Parallel to this is the Vibo Valentia Fault mapped onshore. Southeast-dipping faults have also been proposed, of which only the Sant'Eufemia Fault has been fully mapped out, based on seismic reflection data. Finally the WNW-ESE trending Coccorino Fautl has been suggested on the southern side of the Capo Vaticano, with a possible parallel offshore fault, the Western Offshore Fault. [12] It has also been suggested that the earthquake was a result of a normal fault rupture within the slab of African plate oceanic crust subducting beneath Calabria, at a depth of 35–55 km. [13]
Several of the proposed models have been tested by modelling of either the observed tsunami effects or seismic intensities or both. [12]
A small tsunami was triggered that affected the shores of the Gulf of Saint Euphemia, particularly to the north. Effects were also observed to the southwest of Capo Vaticano and as far away as Milazzo and along other parts of the coast of Sicily. [8] At Bivona (now a suburb of Vibo Valentia) there was 30 m of inundation and a boat was pushed onshore. At Briatico anchored boats were carried onshore by 7–8 m, along with many dead fish. At Tropea several boats that were on the beach were carried out to sea. Further to the north at Scalea, there was more than 30 m of inundation and several beached boats were taken out to sea. [10]
The submarine telegraph cable connecting the Aeolian Islands to Milazzo on Sicily was broken at a depth of 1180 m, presumably by a turbidity current caused by slope failure triggered by the earthquake. [10]
The provinces of Catanzaro (including what is now the Province of Vibo Valentia), Cosenza and Reggio Calabria were the most affected parts of Calabria. 14,000 houses were damaged, [14] with 8,220 houses being destroyed, 6,186 in Catanzaro, 1,000 in Cosenza and 1,034 in Reggio Calabria. In the Vibo Valentia area, the towns of Parghelia, Piscopio and Stefanaconi and several smaller towns, were almost completely destroyed. Many of the houses in the epicentral area were built of "breste" (adobe type) construction and these performed very poorly in the earthquake. [8]
The earthquake triggered many landslides, with at least 42 sites being recorded. The village of Martirano, which has been repeatedly affected by landslides triggered by earthquakes in the past, had one side destroyed by a landslide. [15] Evidence of ground fissures and liquefaction was widespread and many streams and springs were changed in both flow rate and temperature, immediately after the earthquake. [10] [8]
Mario Baratta, writing in 1906, observed that level of damage was related to the underlying geology. He noted that structures built on limestone, molasse, breccia and schist suffered the greatest damage, while those constructed on granite fared much better. [8]
Immediate aid was organised by the Prefects, using civil and military engineers and local medical and military personnel. Temporary accommodation was provided for some of the people made homeless with the building of wooden shacks. In October 1906 the Prefect of Cantanzaro reported that many families remained homeless, while those in the shacks were affected by their poor quality, with both wind and rain being able to penetrate these structures. Other families stayed in ruined houses in a dangerous condition, using a few poorly repaired rooms. He also stated that many farmers had emigrated from the area. [8]
On 25 June a new state law came into force to provide assistance for the most affected areas, including the waiving of some tax instalments. [8]
Some settlements, such as Favelloni and Castiglione Cosentino were moved to new sites. [8] The part of Martirano that was levelled by the landslide was rebuilt on a new site nearby. [15]
An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.
A foreshock is an earthquake that occurs before a larger seismic event – the mainshock – and is related to it in both time and space. The designation of an earthquake as foreshock, mainshock or aftershock is only possible after the full sequence of events has happened.
The 1693 Sicily earthquake was a natural disaster that struck parts of southern Italy near Sicily, then a territory part of the Crown of Aragon by the Kings of Spain Calabria and Malta, on 11 January at around 21:00 local time. This earthquake was preceded by a damaging foreshock on 9 January. The main quake had an estimated magnitude of 7.4 on the moment magnitude scale, the most powerful in recorded Italian history, and a maximum intensity of XI (Extreme) on the Mercalli intensity scale, destroying at least 70 towns and cities, seriously affecting an area of 5,600 square kilometres (2,200 sq mi) and causing the death of about 60,000 people.
The 1703 Apennine earthquakes were a sequence of three earthquakes of magnitude ≥6 that occurred in the central Apennines of Italy, over a period of 19 days. The epicenters were near Norcia, Montereale and L'Aquila, showing a southwards progression over about 36 kilometres (22 mi). These events involved all of the known active faults between Norcia and L'Aquila. A total of about 10,000 people are estimated to have died as a result of these earthquakes, although because of the overlap in areas affected by the three events, casualty numbers remain highly uncertain.
The 1783 Calabrian earthquakes were a sequence of five strong earthquakes that hit the region of Calabria in southern Italy, the first two of which produced significant tsunamis. The epicenters form a clear alignment extending nearly 100 km from the Straits of Messina to about 18 km SSW of Catanzaro. The epicenter of the first earthquake occurred in the plain of Palmi. The earthquakes occurred over a period of nearly two months, all with estimated magnitudes of 5.9 or greater. Estimates of the total number of deaths lie in the range 32,000 to 50,000.
The 1992 Cape Mendocino earthquakes occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino triple junction, a complex system of three major faults that converge near Cape Mendocino. The total number of aftershocks that followed the events exceeded 2,000.
The 1968 Belice earthquake sequence took place in Sicily between 14 and 15 January. The largest shock measured 5.5 on the moment magnitude scale, with five others of magnitude 5+. The maximum perceived intensity was X (Extreme) on the Mercalli intensity scale. The earthquake sequence, centred between the towns of Gibellina, Salaparuta and Poggioreale, killed at least 231 people, possibly more than 400, with between 632 and about 1,000 injured and left 100,000 homeless. It is known in Italy as Terremoto del Belice.
The 1169 Sicily earthquake occurred on 4 February 1169 at 08:00 local time on the eve of the feast of St. Agatha of Sicily. It had an estimated magnitude of between 6.4 and 7.3 and an estimated maximum perceived intensity of X (Extreme) on the Mercalli intensity scale. The cities of Catania, Lentini and Modica were severely damaged, and the earthquake also triggered a paleotsunami. Overall, the earthquake is estimated to have caused the deaths of at least 15,000 people.
The Gulf of Saint Euphemia is a gulf on the west coast of Calabria, southern Italy. It is part of the Tyrrhenian Sea and borders the province of Cosenza, the province of Catanzaro, and the province of Vibo Valentia.
The 1946 Sagaing earthquakes struck central Burma at 15:17 local time on 12 September. The first earthquake measured a magnitude of 7.3 Mw and was followed by a 7.7 Mw earthquake. Both events remain some of the largest in the country since the 1762 Arakan earthquake.
On January 1, 1996, at 4:05 p.m. Central Indonesia Time, an earthquake with an epicenter in the Makassar Strait struck north of Minahasa on the island of Sulawesi, Indonesia. The earthquake measured 7.9 on the moment magnitude scale and was centered off Tolitoli Regency in Central Sulawesi, or 25 km from the Tonggolobibi village. A tsunami of 2–4 m (6.6–13.1 ft) was triggered by this earthquake as a result. At least 350 buildings were badly damaged, nine people died and 63 people were injured.
The 1900 Venezuelan earthquake also known as the San Narciso earthquake, occurred on October 28 at between 4:30 and 4:45 am local time. This earthquake had an epicenter off Miranda State or near the Venezuelan capital Caracas, in the Cariaco Basin. It had an estimated moment magnitude of 7.6–7.7 and a surface-wave magnitude of 7.7–8.4. It had a maximum Mercalli intensity assigned VIII–X, causing landslides and liquefaction events. Many buildings were severely damaged or collapsed during the earthquake. It is thought to be the last great earthquake of the 19th century and the largest instrumentally recorded in the republic, having been felt throughout.
The 1995 Menglian earthquake or 1995 Myanmar–China earthquake occurred on 12 July at 05:46:43 local time in the Myanmar–China border region. The earthquake had an epicenter on the Myanmar side of the border, located in the mountainous region of Shan State. It registered 7.3 on the Chinese surface-wave magnitude scale (Ms ) and 6.8 on the moment magnitude scale (Mw ). With a maximum Mercalli intensity assigned at VIII, it killed 11 people and left another 136 injured. Over 100,000 homes in both countries were destroyed and 42,000 seriously damaged. Some damage to structures were also reported in Chiang Mai and Chiang Rai, Thailand. The low death toll from this earthquake was attributed to an early warning issued prior to it happening. Precursor events including foreshocks and some seismic anomalies led to an evacuation of the area before the mainshock struck. It is thought to be one of the few successfully predicted earthquakes in history.
The 1990 Carlentini earthquake occurred off the Sicilian coast, 20 km east northeast from the town of Augusta, Sicily on 13 December at 01:24 local time. The moderately-sized earthquake measuring 5.6 on the moment magnitude scale (Mw ) resulted in the deaths of 19 people and caused at least 200 injuries. It also inflicted significant damage in the region, leaving 2,500 homeless.
The 1993 Finisterre Range earthquakes began on October 13 with a Mw 6.9 mainshock, followed by Mw 6.5 and 6.7 earthquakes. These earthquakes struck beneath the Finisterre Range, north of Markham Valley in Morobe Province, Papua New Guinea. The complex earthquake sequence seriously damaged many villages in the rural Eastern Papua New Guinea region, generating landslides and killing at least 60 people.
On December 5, 1456, the largest earthquake to occur on the Italian Peninsula in historical times struck the Kingdom of Naples. The earthquake had an estimated moment magnitude of Mw 7.19–7.4, and was centred near the town of Pontelandolfo in the present-day Province of Benevento, southern Italy. Earning a level of XI (Extreme) on the Modified Mercalli intensity scale, the earthquake caused widespread destruction in central and southern Italy. Estimates of the death toll range greatly with up to 70,000 deaths reported. It was followed by two strong Mw 7.0 and 6.0 earthquakes to the north on December 30. The earthquake sequence is considered the largest in Italian history, and one of the most studied.
A series of mainshocks struck Calabria on March 27–28 and June 9, 1638. The first three earthquakes had moment magnitudes estimated to be Mw 6.6–7.1. On June 9, another mainshock estimated at Mw 6.7 struck the same region, causing further damage and casualties. The four earthquakes resulted in as many as 30,000 fatalities.
The second shock in the 1962 Irpinia earthquake sequence was the largest and most destructive in a series of earthquakes in the southern Apennines. It occurred on 21 August at 18:19 CET, measuring Mw 6.15 and assigned a maximum intensity of IX (Violent). It was preceded by an Mw 5.68 foreshock, and followed by a 5.34 aftershock. The earthquakes resulted in nearly 20 fatalities and significant property losses.
The 1983 Kaoiki earthquake struck southern Hawaii Island on the morning of November 16, 1983. Measuring Mw 6.7, it was the largest to hit the island since 1975. The epicenter was located 50 km (30 mi) southeast of Hilo with an approximated depth of 12 km (7 mi). The shallow strike-slip earthquake was assigned a maximum intensity of IX (Violent) on the Modified Mercalli scale. 6 people were injured, widespread damage and landslides were reported across the island.
The Siculo-Calabrian rift is a zone of active extensional tectonics running about 200 km from northern Calabria to near Syracuse in Sicily. It is formed of a series of overlapping normal faults that control graben and half-graben on their downthrown sides. These faults have regularly ruptured historically, causing destructive earthquakes, often in sequences, such as the 1783 Calabrian earthquakes.