Earthquake with magnitude of Md 2.5 on date 21-07-1991 and time 18:42:23 (Italy) in region 5 km SE Cerreto di Spoleto (PG)

A magnitude Md 2.5 earthquake occured in region: 5 km SE Cerreto di Spoleto (PG), on

  • 21-07-1991 16:42:23 (UTC)
  • 21-07-1991 18:42:23 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.78, 12.95 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
Cerreto di Spoleto PG 5 1075 1075
Vallo di Nera PG 8 364 1439
Poggiodomo PG 8 117 1556
Cascia PG 9 3217 4773
Sant'Anatolia di Narco PG 11 564 5337
Norcia PG 12 4957 10294
Sellano PG 12 1079 11373
Preci PG 13 724 12097
Scheggino PG 13 461 12558
Monteleone di Spoleto PG 15 599 13157
Campello sul Clitunno PG 15 2442 15599
Spoleto PG 18 38218 53817
Trevi PG 20 8469 62286
Visso MC 20 1107 63393

Municipalities with at least 50000 inhabitants

An earthquake occurred to
28 Km SE of Foligno (57155 inhabitants)
35 Km NE of Terni (111501 inhabitants)
58 Km SE of Perugia (166134 inhabitants)
60 Km NW of L'Aquila (69753 inhabitants)
63 Km W of Teramo (54892 inhabitants)
81 Km NE of Viterbo (67173 inhabitants)
89 Km N of Guidonia Montecelio (88673 inhabitants)
92 Km N of Tivoli (56533 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
Rev 1000 Md 2.5
ML-VAX 1.7
1991-07-21
16:42:23
42.78 12.95 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 145949
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-07-21 16:42:23 ± 0.137
Latitude 42.78 ± 0.01
Longitude 12.95 ± 0.01
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 145949

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) 1422.1
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 112
Number of associated phases, regardless of their use for origin computation 15
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00227
Epicentral distance of station farthest from the epicenter (degree) 0.01117
Number of stations at which the event was observed 9
Number of stations from which data was used for origin computation 9
Magnitudes information

Md:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 145949
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:16:15

ML:1.7

Field Value
Value 1.7
Uncertainty
Num. used stations 3
Type of magnitude ML
Reference to an origin 145949
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 13:07:13
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.ARV.Z. 1991-07-21T16:42:49.50 10.0 undecidable manual SG 359 0.0064 1.35 0
--.SDI.Z. 1991-07-21T16:42:47.00 10.0 undecidable manual PN 149 0.0112 0.52 0.4
--.CRE.Z. 1991-07-21T16:42:44.50 10.0 undecidable manual PN 319 0.01 -0.1 1.1
--.ALP.Z. 1991-07-21T16:42:39.85 10.0 undecidable manual SG 90 0.004 0.2 0.6
--.MNS.Z. 1991-07-21T16:42:39.60 10.0 undecidable manual SG 206 0.004 -0.52 0.3
--.CIO.Z. 1991-07-21T16:42:38.21 10.0 undecidable manual SG 18 0.0039 -0.91 0
--.ARV.Z. 1991-07-21T16:42:37.45 10.0 undecidable manual PG 359 0.0064 -0.2 1.3
--.ASS.Z. 1991-07-21T16:42:36.91 10.0 undecidable manual SG 321 0.0032 0.29 0.5
--.AQU.Z. 1991-07-21T16:42:34.56 10.0 undecidable manual PG 142 0.0049 0.1 1.7
--.RMF.Z. 1991-07-21T16:42:33.14 10.0 undecidable manual SG 47 0.0023 -0.18 0.6
--.CIO.Z. 1991-07-21T16:42:32.23 10.0 undecidable manual PG 18 0.0039 -0.21 1.5
--.ALP.Z. 1991-07-21T16:42:32.53 10.0 undecidable manual PG 90 0.004 -0.21 1.5
--.MNS.Z. 1991-07-21T16:42:32.62 10.0 undecidable manual PG 206 0.004 -0.08 1.7
--.ASS.Z. 1991-07-21T16:42:30.91 10.0 undecidable manual PG 321 0.0032 -0.09 1.7
--.RMF.Z. 1991-07-21T16:42:29.12 10.0 undecidable manual PG 47 0.0023 0.03 1.8
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
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