Earthquake with magnitude of Md 2.5 on date 22-05-1991 and time 16:31:27 (Italy) in region 4 km SE Norcia (PG)

A magnitude Md 2.5 earthquake occured in region: 4 km SE Norcia (PG), on

  • 22-05-1991 14:31:27 (UTC)
  • 22-05-1991 16:31:27 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7720, 13.1310 at 10 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

Search earthquakes: Any within 30 km radius

The values of hypocentral coordinates and magnitude may be revised at a later time as more information becomes available.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Norcia PG 4 4957 4957
Cascia PG 11 3217 8174
Accumoli RI 13 667 8841
Arquata del Tronto AP 14 1178 10019
Castelsantangelo sul Nera MC 14 281 10300
Preci PG 14 724 11024
Cittareale RI 17 482 11506
Poggiodomo PG 17 117 11623
Visso MC 18 1107 12730
Cerreto di Spoleto PG 18 1075 13805
Montegallo AP 18 523 14328
Ussita MC 19 444 14772
Monteleone di Spoleto PG 20 599 15371

Municipalities with at least 50000 inhabitants

An earthquake occurred to
40 Km SE of Foligno (57155 inhabitants)
46 Km NE of Terni (111501 inhabitants)
49 Km W of Teramo (54892 inhabitants)
52 Km NW of L'Aquila (69753 inhabitants)
71 Km SE of Perugia (166134 inhabitants)
88 Km W of Montesilvano (53738 inhabitants)
92 Km NE of Guidonia Montecelio (88673 inhabitants)
93 Km E of Viterbo (67173 inhabitants)
94 Km N of Tivoli (56533 inhabitants)
95 Km W of Pescara (121014 inhabitants)
97 Km W of Chieti (51815 inhabitants)
99 Km SW of Ancona (100861 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
Felt maps
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Bulletin
Rev1000
Md 2.5 1991-05-22
14:31:27
42.772 13.131 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 141739
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-05-22 14:31:27 ± 0.642
Latitude 42.7720 ± 0.0166
Longitude 13.1310 ± 0.0590
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 141739

Uncertainty

Field Value
Preferred uncertainty description horizontal uncertainty
Semi-major axis of confidence ellipse (meter)
Semi-minor axis of confidence ellipse (meter)
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi)
Circular confidence region, given by single value of horizontal uncertainty (meter) 5155.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 231
Number of associated phases, regardless of their use for origin computation 8
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.5
Epicentral distance of station closest to the epicenter (degree) 0.00405
Epicentral distance of station farthest from the epicenter (degree) 0.01085
Number of stations at which the event was observed 4
Number of stations from which data was used for origin computation 4
Magnitude information

Md:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 141739
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:12:19
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.CRE.Z. 1991-05-22T14:32:07.00 10.0 undecidable manual SN 314 1.1988 0.64 0.5
--.ARV.Z. 1991-05-22T14:31:52.00 10.0 undecidable manual SG 349 0.7326 -0.82 0.4
--.CRE.Z. 1991-05-22T14:31:51.50 10.0 undecidable manual PN 314 1.1988 1.71 0.2
--.MNS.Z. 1991-05-22T14:31:45.00 10.0 undecidable manual SG 220 0.4995 -0.43 0.7
--.ASS.Z. 1991-05-22T14:31:43.50 10.0 undecidable manual SG 309 0.444 -0.19 0.8
--.ARV.Z. 1991-05-22T14:31:41.50 10.0 undecidable manual PG 349 0.7326 -0.48 1.6
--.MNS.Z. 1991-05-22T14:31:37.50 10.0 undecidable manual PG 220 0.4995 -0.21 1.9
--.ASS.Z. 1991-05-22T14:31:36.50 10.0 undecidable manual PG 309 0.444 -0.21 1.9
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download