January 2017 Central Italy earthquakes explained

Timestamp:2017-01-18 10:14:10
Isc-Event:611831611
Anss-Url:us10007twj
Local-Time:11:14:10 (CET)
Magnitude:5.7
Depth:7km (04miles)
Intensity: [1]
Casualties:34 deaths
January 2017 Central Italy earthquakes
Countries Affected:Central Italy

A series of four major earthquakes struck Central Italy between Abruzzo, Lazio, the Marche and Umbria regions on 18 January 2017.[2] [3]

Earthquakes

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.[4] A stronger, 5.7 tremor hit the same epicentral area at 11:14 local time.[5] A third earthquake of preliminary magnitude of 5.6 struck 11 minutes later.[6] At 14:33 local time, the fourth tremor of magnitude 5.2 was registered.[7] These earthquakes were followed by multiple aftershocks.

The earthquakes were strongly felt in other parts of central Italy, including the city of Rome, where the metro system and many schools were evacuated.[8] The strongest tremor was also felt in coastal parts of Croatia (with an intensity of III).[9] Five deaths were reported in Teramo, Crognaleto and Campotosto.[10] These earthquakes also appeared to have triggered, in combination with a winter storm, the Rigopiano avalanche a few hours later, that struck a hotel.

Avalanche

See main article: Rigopiano avalanche. During the evening of 18 January, the Rigopiano Hotel in the Gran Sasso mountain near Farindola in the Abruzzo region was struck by an avalanche, thought to have been triggered by the earthquakes, leaving several dead.[11] There were forty people in the hotel when the avalanche struck, including twenty-eight guests and twelve employees[12] Twenty-nine people were confirmed dead from the avalanche.[13] A total of nine people were rescued,[14] [15] and two other people survived because they had been standing outside of the hotel when the avalanche hit. A person died in Castel Castagna.[16] [17]

It was reported that shortly after the earthquake hit the region, hotel guests were gathered on the ground floor of the hotel, awaiting evacuation when the avalanche struck. Upon impact, the avalanche caused part of the roof of the hotel to collapse, and moved it 10 meters (33 feet) down the mountain.[18]

Shocks

Date / time
(UTC)
MagnitudeTypeDepth
Hypocenter
Epicenter
LocationLatitudeLongitude
2017-01-18   09:25:405.39.0 kmMontereale42.5513.26
2017-01-18   10:14:095.79.0 kmCapitignano42.5313.28
2017-01-18   10:15:334.710.0 kmCapitignano42.5313.29
2017-01-18   10:16:394.711.0 kmCapitignano42.5513.28
2017-01-18   10:25:235.69.0 kmCapitignano42.4913.31
2017-01-18   13:33:365.210.0 kmCagnano Amiterno42.4813.28

Geological aspects

The quakes occurred in a seismic gap which is located between the areas hit by the August 2016 earthquake, the October 2016 earthquakes and the one in Umbria and Marche in 1997. In that gap, no strong earthquake happened for more than 100 years[19] until 2016.

The rapid succession of four bursts of seismic activity in three hours, all of which with a magnitude higher than 5 was described as "a novel phenomenon in recent history" by seismologists from the National Institute of Geophysics and Volcanology of Italy.[20] The same scientists compared it with the 1980 Irpinia earthquake, where three different quakes happened in 80 seconds.

As the process of faulting along the chain of the Apennine Mountains is a relatively recent one in geological terms, starting 500,000 years ago, the faults are more irregular, so more shaking occurs due to foreshocks according to seismologist Ross Stein from Stanford University.

See also

External links

Notes and References

  1. A. Rossi . A. Tertulliani . R. Azzaro . L. Graziani . A. Rovida . A. Maramai . V. Pessina . S. Hailemikael . G. Buffarini . F. Bernardini . R. Camassi . S. Del Mese . E. Ercolani . A. Fodarella . M. Locati . G. Martini . A. Paciello . S. Paolini . L. Arcoraci . C. Castellano . V. Verrubbi . M. Stucchi . The 2016–2017 earthquake sequence in Central Italy: macroseismic survey and damage scenario through the EMS-98 intensity assessment . Bulletin of Earthquake Engineering . 2019 . 17 . 5 . 2407–2431 . 10.1007/s10518-019-00556-w . 2019BuEE...17.2407R . 116854125 .
  2. Web site: Terremoto, 4 scosse sopra magnitudo 5: torna la paura nel Centro Italia in ginocchio per la neve. 18 January 2017. 18 January 2017.
  3. Web site: M 5.7 - 6km WSW of Amatrice, Italy. United States Geological Survey. 16 March 2017. 18 January 2017.
  4. Web site: Earthquake, Magnitude 5.3 – CENTRAL ITALY – 2017 January 18, 09:25:40 UTC. 18 January 2017.
  5. Web site: Earthquake, Magnitude 5.7 – CENTRAL ITALY – 2017 January 18, 10:14:10 UTC. 18 January 2017.
  6. Web site: Earthquake, Magnitude 5.6 – CENTRAL ITALY – 2017 January 18, 10:25:25 UTC. 18 January 2017.
  7. Web site: Earthquake, Magnitude 5.2 – CENTRAL ITALY – 2017 January 18, 13:33:37 UTC. 18 January 2017.
  8. Web site: Rome's subway evacuated as quakes rock Italy. Angela Dewan . Barbie Nadeau. CNN. 19 January 2017.
  9. Web site: Geofizički odsjek PMF-a. gfz.hr. 19 January 2017.
  10. News: Sisma, due morti a Campotosto e tre nel Teramano – Tgcom24. Tgcom24. 20 January 2017.
  11. Web site: 'Many dead' in avalanche on Italy hotel in the Abruzzo. BBC News . 19 January 2017 . 19 January 2017 .
  12. Web site: Hotel travolto da valanga, quattro morti e oltre 25 dispersi: "Aspettavano spazzaneve per andare via". 19 January 2017 .
  13. Web site: Italy's Rigopiano hotel death toll reaches 29, rescue operation over. TASS Russian News Agency. 26 January 2017.
  14. News: Denti. Antonio. More survivors in Italian avalanche hotel as death toll rises to five. Reuters. 21 January 2017 . 21 January 2017.
  15. Web site: Miracolo Rigopiano: 10 ancora vivi, salvati 4 bambini. 20 January 2017.
  16. Web site: Giuffrida. Angela. Italy avalanche: many feared dead as Rigopiano hotel engulfed. The Guardian. 19 January 2017 . 19 January 2017.
  17. Web site: Killer avalanche turns Italian hotel into 'coffin'. Agence France-Presse. 19 January 2017. dead. https://web.archive.org/web/20170119191438/https://www.afp.com/en/news/23/killer-avalanche-turns-italian-hotel-coffin. 19 January 2017.
  18. News: Rigopiano hotel avalanche: Italian rescuers find no sign of life. 19 January 2017 . BBC News. 19 January 2017.
  19. since there is that 1879 quake in the map, not more offside than the actual quake its safer to say so, instead telling the 157 years from source spiegel.de
  20. News: Ingv, quattro terremoti in tre ore, mai vista una serie simile – Terra e Poli – Scienza&Tecnica. ANSA.it. ANSA. 18 January 2017. Italian.