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Note:This page contains AI-generated content for informational and entertainment purposes only. It may contain inaccuracies. Raw event data is from USGS and EMSC. All statistics, lists, and derived information are generated by this site. Full disclaimerFound an error?
Location:
CENTRAL ITALY
Period:
5 Mar 2011 17:13:03 - 13 Mar 2011 18:48:08 (8 days 1 hour 35 minutes)
Volcanoes in 100km radius:
Colli Albani(99km)
Earthquakes:
87
16 swarms found nearby.
2007
S20070208.1(27.7km)
8 Feb
1 day 3 hours
26 earthquakes
2009
S20090330.1(26.5km)
30 Mar
98 days 16 hours
6163 earthquakes
9 May
13 days 16 hours
178 earthquakes
25 Jun
3 days 7 hours
118 earthquakes
12 Jul
6 days 5 hours
128 earthquakes
S20090801.1(17.8km)
31 Jul
19 days 15 hours
224 earthquakes
22 Aug
6 days 9 hours
83 earthquakes
2010
30 Aug
25 days 22 hours
427 earthquakes
30 Sep
11 days 3 hours
111 earthquakes
S20101020.1(10.9km)
19 Oct
6 days 18 hours
375 earthquakes
3 Nov
6 days 0 hours
176 earthquakes
2011
S20110215.1(21.2km)
15 Feb
1 day 8 hours
27 earthquakes
S20111019.2(10.0km)
18 Oct
1 day 4 hours
25 earthquakes
2016
S20160824.1(28.1km)
24 Aug
15 days 11 hours
415 earthquakes
S20161030.1(14.9km)
30 Oct
3 days 20 hours
72 earthquakes
2017
18 Jan
5 days 9 hours
231 earthquakes
AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm S20110306.1: Analysis of Central Italy Activity in March 2011

Central Italy occupies a tectonically active zone within the Apennine mountain belt, where ongoing extension arises from the rollback of the Adriatic slab beneath the Eurasian plate. This setting produces frequent normal-faulting earthquakes at shallow crustal depths, typically between 5 and 15 km. The region has long been recognized for clusters of low-to-moderate magnitude events that occur in swarms rather than as isolated mainshock-aftershock sequences.

Seismic swarm S20110306.1 was recorded in this environment between 17:13 UTC on 5 March 2011 and 18:48 UTC on 13 March 2011. Over 193 hours and 35 minutes, 87 earthquakes were detected. Magnitudes ranged from 1.1 to 3.0, with the largest event occurring at 00:14 UTC on 6 March at a depth of 10 km. Focal depths remained predominantly shallow, consistent with the extensional regime of the central Apennines.

The temporal evolution showed the highest event rate during the first 48 hours, followed by a gradual decline. Early activity included multiple events above magnitude 2.0 on 6 March, while later days featured lower-magnitude, more sporadic occurrences. Depths clustered between 5 and 13 km, with occasional events reaching 15–19 km, reflecting the brittle-ductile transition typical of the area.

Historical records indicate that seismic swarms are recurrent in central Italy. Since 1 January 2000, twelve such swarms have been documented, with notable concentrations in 2009 (six swarms) and 2010 (four swarms). The 2011 swarm represents the sole episode recorded that year. These clusters underscore the region’s tendency toward distributed microseismicity along segmented normal faults rather than large single ruptures.

The modest energy release of swarm S20110306.1 aligns with background seismicity levels observed in the central Apennines. No damage or felt reports beyond light shaking were associated with the sequence, consistent with the maximum magnitude of 3.0.

References

  • Istituto Nazionale di Geofisica e Vulcanologia (INGV) seismic catalog
  • SeismoSight internal swarm classification database
  • Geological Survey of Italy tectonic framework reports