Earthquake with magnitude of Md 2.5 on date 20-12-1991 and time 23:52:05 (Italy) in region 1 km E Castel Ritaldi (PG)

A magnitude Md 2.5 earthquake occured in region: 1 km E Castel Ritaldi (PG), on

  • 20-12-1991 22:52:05 (UTC)
  • 20-12-1991 23:52:05 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.8230, 12.6820 at 5 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
Castel Ritaldi PG 1 3278 3278
Campello sul Clitunno PG 8 2442 5720
Trevi PG 8 8469 14189
Montefalco PG 8 5679 19868
Giano dell'Umbria PG 9 3846 23714
Spoleto PG 11 38218 61932
Bevagna PG 14 5081 67013
Massa Martana PG 14 3770 70783
Gualdo Cattaneo PG 14 6155 76938
Foligno PG 15 57155 134093
Vallo di Nera PG 16 364 134457
Sant'Anatolia di Narco PG 16 564 135021
Scheggino PG 17 461 135482
Acquasparta TR 18 4778 140260
Spello PG 19 8645 148905
Cerreto di Spoleto PG 19 1075 149980

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km S of Foligno (57155 inhabitants)
29 Km N of Terni (111501 inhabitants)
40 Km SE of Perugia (166134 inhabitants)
65 Km NE of Viterbo (67173 inhabitants)
79 Km NW of L'Aquila (69753 inhabitants)
86 Km W of Teramo (54892 inhabitants)
92 Km N of Guidonia Montecelio (88673 inhabitants)
96 Km N of Tivoli (56533 inhabitants)
97 Km SE of Arezzo (99543 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 1991-12-20
22:52:05
42.823 12.682 5 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 155439
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-12-20 22:52:05 ± 0.179
Latitude 42.8230 ± 0.0070
Longitude 12.6820 ± 0.0338
Depth (km) 5 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 155439

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) 2864.7
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 185
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) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00210
Epicentral distance of station farthest from the epicenter (degree) 0.01109
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 155439
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:25:10
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.SFI.Z. 1991-12-20T22:52:46.50 10.0 undecidable manual SN 330 1.2321 -0.41 0.3
--.CRE.Z. 1991-12-20T22:52:39.00 10.0 undecidable manual SG 326 0.9546 -0.22 0.6
--.SFI.Z. 1991-12-20T22:52:30.00 10.0 undecidable manual PN 330 1.2321 0.55 0.5
--.CRE.Z. 1991-12-20T22:52:25.10 10.0 undecidable manual PG 326 0.9546 0.09 2
--.MNS.Z. 1991-12-20T22:52:23.00 10.0 undecidable manual SG 180 0.4329 0.47 0.4
--.ASS.Z. 1991-12-20T22:52:15.00 10.0 undecidable manual SG 354 0.2331 -0.02 0.9
--.MNS.Z. 1991-12-20T22:52:15.00 10.0 undecidable manual PG 180 0.4329 -0.38 1.1
--.ASS.Z. 1991-12-20T22:52:11.00 10.0 undecidable manual PG 354 0.2331 -0.04 2.3
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