1703 Apennine earthquakes
{{Short description|Series of earthquakes in Italy}}
{{Use dmy dates|date=October 2024}}
{{Infobox earthquake
| title = 1703 Apennine earthquakes
|pre-1900 = yes
| local-date = {{Start-date|14 January 1703}}
| map2 = {{Location map+ | Italy Center#Italy
| float = none
| width = 250
| places =
{{Location map~ | Italy Center#Italy
| label = 14 January
| lat = 42.709
| long = 13.070
| mark = Cercle rouge 100%.svg
| marksize = 8
| position = left }}
{{Location map~ |Italy Center# Italy
| label = 16 January
| lat = 42.623
| long = 13.102
| mark = Cercle rouge 100%.svg
| marksize = 8
| position = right }}
{{Location map~ | Italy Center#Italy
| label = 2 February
| lat = 42.435
| long = 13.292
| mark = Cercle rouge 100%.svg
| marksize = 8
| position = left }}
| relief=yes
| caption =}}
| magnitude = 6.7–6.2–6.7 ML
| depth =
| location = {{Coord|42.7|13.07|display=inline}}
(first event)
| countries affected = Italy
| tsunami =
| casualties = 10,000 deaths
}}
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 (14 January), Montereale (16 January) and L'Aquila (2 February), showing a southwards progression over about {{convert|36|km}}. 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,{{cite web|title=Seismically Induced Ground Ruptures and Large Scale Mass Movements: Field Excursion and Meeting 21–27 september 2001|url=http://www.apat.gov.it/site/_contentfiles/00037500/37545_atti_2002_04.pdf|archive-url=https://web.archive.org/web/20110717121523/http://www.apat.gov.it/site/_contentfiles/00037500/37545_atti_2002_04.pdf|archive-date=17 July 2011|url-status=dead|access-date=25 September 2009}} although because of the overlap in areas affected by the three events, casualty numbers remain highly uncertain.
Tectonic setting
The central part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last 5 million years), with most of the active faults being normal in type and NW-SE trending.{{cite journal|url=http://www.bssaonline.org/cgi/content/abstract/99/2A/585?stoc|title=Effect of Time Dependence on Probabilistic Seismic-Hazard Maps and Deaggregation for the Central Apennines, Italy|journal=The Bulletin of the Seismological Society of America|volume=99|issue=2A|pages=585|date=6 April 2009|access-date=6 April 2009|publisher=Seismological Society of America|archive-url=https://web.archive.org/web/20090410080953/http://www.bssaonline.org/cgi/content/abstract/99/2A/585?stoc|archive-date=10 April 2009|url-status=live|bibcode=2009BuSSA..99..585A|last1=Akinci|first1=A.|last2=Galadini|first2=F.|last3=Pantosti|first3=D.|last4=Petersen|first4=M.|last5=Malagnini|first5=L.|last6=Perkins|first6=D.|doi=10.1785/0120080053}} The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the African plate is colliding with the Eurasian plate.{{cite web|url=https://earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009fcaf/#summary|title=Magnitude 6.3 – CENTRAL ITALY 2009 April 06 01:32:42 UTC|date=6 April 2009|access-date=6 April 2009|publisher=United States Geological Survey|archive-url=https://web.archive.org/web/20090409075310/http://earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009fcaf/|archive-date=9 April 2009 }}
The Norcia earthquake
The earthquake occurred at 18:00 UTC on 14 January with an estimated magnitude of 6.7.{{cite web|title=IISEENET (Information Network of Earthquake disaster Prevention Technologies) – Search Page|url=http://iisee.kenken.go.jp/utsu/utsuweq_bak_eng.html|archive-url=https://web.archive.org/web/20100721030928/http://iisee.kenken.go.jp/utsu/utsuweq_bak_eng.html|archive-date=21 July 2010|url-status=live|access-date=25 September 2009}} It was caused by movement on an en echelon set of three normal faults, known as the Norcia Fault System.
=Damage=
There was extensive damage in the area around Norcia, with Spoleto and Rieti also affected. Modern estimates give a maximum Mercalli intensity of XI (Extreme).{{cite web|url=http://www.apat.gov.it/site/_files/Inqua/2009_abruzzo_earthquake_report.pdf|title=Geological effects induced by the L'Aquila earthquake (6 April 2009, Ml = 5.8) on the natural environment: preliminary report|access-date=21 May 2012|url-status=dead|archive-url=https://web.archive.org/web/20120217201758/https://www.apat.gov.it/site/_files/Inqua/2009_abruzzo_earthquake_report.pdf|archive-date=17 February 2012}} Ground rupture was observed at several locations and these have been confirmed by modern investigations.
=Casualties=
Estimates of the death toll vary from 6,240{{cite web|url=https://archive.org/stream/sciencetechnolog07wolpuoft/sciencetechnolog07wolpuoft_djvu.txt|title=Davison, C. 1912–1913. The death-rate of earthquakes, Science progress in the twentieth century, A quarterly journal of Scientific work & thought|access-date=21 May 2012}} to 9,761.
The Montereale earthquake
The earthquake occurred at 13:30 UTC on 16 January with an estimated magnitude of 6.2. It is thought to have been caused by movement on the Montereale Fault. Damage was recorded in Montereale, Cittareale, Accumoli and Amatrice. Although of lower magnitude than the other two events, this earthquake was still felt in Rome. The estimated intensity for this event is VIII (Severe). No separate casualty figures are available for this event.
The L'Aquila earthquake
=Damage=
Most of the buildings in L’Aquila were badly damaged or completely destroyed. Damage was reported from as far away as Rome.{{cite web|url=http://legacy.ingv.it/roma/attivita/pererischio/macrosismica/Hist/Storiadeipapi_en.html|title=Description of the effects in Rome caused by the three earthquakes|publisher=Legacy.ingv.it|access-date=21 May 2012}} Modern estimates give a maximum intensity of X (Extreme). The earthquake caused a huge landslide on the Mt. Marine ridge, a large slope failure near Posta and liquefaction along the Aterno River.
=Casualties=
Estimates of the death toll vary from 2,500 to 5,000.{{cite book|first=Georges Louis Leclerc|last=Buffon|title=Buffon's Natural History|volume=2|publisher=J.S. Barr|year=1792|oclc=316760617|location=London}}
Summary of earthquakes
Details taken from Catalogue of Strong Earthquakes in Italy (461 BC – 1997) and Mediterranean Area (760 B.C. – 1500){{Cite web|url=http://storing.ingv.it/cfti/cfti5/quake.php?01148IT|title=Catalogue of Strong Earthquakes in Italy (461 BC – 1997) and Mediterranean Area (760 B.C. – 1500)|last=Guidoboni|first=E.|last2=Ferrari|first2=G.|last3=Mariotti|first3=D.|last4=Comastri|first4=A.|last5=Tarabusi|first5=G.|last6=Sgatoni|first6=G.|last7=Valensise|first7=G.|publisher=INGV-SGA|access-date=31 March 2022}}
{{GeoGroup|section=Summary of earthquakes}}
| class=wikitable
! Name!! Date!! Time!! Coordinates!! Magnitude!! Intensity |
| Norcia
| 14 January | 18:00 | {{coord|42.70|13.07|display=inline,title}} | 6.7 | XI |
| Montereale
| 16 January | 13:30 | {{coord|42.62|13.10}} | 6.2 | VIII |
| L'Aquila
| 2 February | 11:05 | {{coord|42.43|13.30}} | 6.7 | X |
Relationship between the events
Some seismologists interpret these events as related. It has been suggested that the Norcia earthquake led directly to the Montereale event, which had the effect of further loading the fault at Aquila, thus triggering the final event.{{cite journal|author=Galli, P.|author2=Galadini, F.|author3=Calzoni, F.|name-list-style=amp|date=2005|title=Surface faulting in Norcia (central Italy): a "paleoseismological perspective|doi=10.1016/j.tecto.2005.04.003|volume=403|issue=1–4|journal=Tectonophysics|pages=117–130|bibcode=2005Tectp.403..117G}} Such sequential adjacent events are examples of coulomb stress transfer.
See also
References
{{Reflist}}
Further reading
- {{citation|last1=Galli|first1=P.|last2=Messina|first2=P.|last3=Peronace|first3=E|last4=Galderisi|first4=A.|last5=Ilardo|first5=I.|last6=Polpetta|first6=F.|title=Paleoseismic evidence of five magnitude 7 earthquakes on the Norcia fault system in the past 8,000 years (Central Italy)|journal=Frontiers in Earth Science|volume=11|year=2023|doi=10.3389/feart.2023.1188602|issn=2296-6463|doi-access=free}}
{{Earthquakes in Italy}}
{{DEFAULTSORT:1703 Apennine Earthquakes}}