Wednesday 26 October 2016

Central Italy shaken by pair of Earthquakes.

The United States Geological Survey recorded two significant Earthquakes in Central Italy on Wednesday 26 October 2016. The first had a Magnitude of 5.5 and occurred 7 km to the southwest of the town of Visso in Macerata Province at a depth of 10 km at about 7.10 pm local time (about 5.10 pm GMT), while the second had a Magnitude of 6.1 km and occurred 2 km to the north of the town, again at a depth of 10 km, slightly before 7.20 pm local time (slightly before 5.20 pm GMT). There are no reports of any injuries following these events, but minor damage has been reported across a wide area, as well as power cuts and one instance of a road being closed by a small landslide. People have reported feeling the event across Central and Northern Italy, as well as in parts of Slovenia and Croatia.

The approximate location of the first 26 October 2016 Visso Earthquake. Google.

The approximate location of the second 26 October 2016 Visso Earthquake. Google.

Italy is in an unusual tectonic setting, with the west of the country lying on the Eurasian Plate, but the east of the country lying on the Adriatic Plate, a microplate which broke away from North Africa some time in the past and which is now wedged into the southern margin of Europe, underlying eastern Italy, the Adriatic Sea and the west of the Balkan Peninsula. This, combined with the northward movement of the African Plate into Italy from the south, leads to uplift in the Apennine Mountains that run the length of the country, and makes Italy extremely prone to Earthquakes. 

Outline map showing the approximate positions of the Eurasian (EU), Adriatic (AD) and African (AF) Plates. Di Bucci & Mazzuli (2003).

Historically Italy has suffered a number of devastating Earthquakes that lead to large numbers of casualties, though in recent decades the country has made serious attempts to prevent this, with better warning systems and tighter building regulations, though the large number of historic buildings in Italy, which cannot easily be replaced (and any attempt to do so would be unlikely to succeed due to their high cultural value), meaning that the country is unlikely to be completely risk free any time soon.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt these quakes then you can report it to Earthquake Report here.
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