Earthquake with magnitude of Md 3.1 on date 17-12-1985 and time 03:33:50 (UTC) in region 3 km S Spoleto (PG)

A magnitude Md 3.1 earthquake occured in region: 3 km S Spoleto (PG), on

  • 17-12-1985 03:33:50 (UTC)
  • 17-12-1985 04:33:50 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.71, 12.74 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
Spoleto PG 3 38218 38218
Scheggino PG 7 461 38679
Sant'Anatolia di Narco PG 8 564 39243
Ferentillo TR 11 1913 41156
Vallo di Nera PG 12 364 41520
Campello sul Clitunno PG 13 2442 43962
Montefranco TR 13 1276 45238
Castel Ritaldi PG 14 3278 48516
Arrone TR 14 2763 51279
Poggiodomo PG 16 117 51396
Polino TR 16 233 51629
Acquasparta TR 16 4778 56407
Monteleone di Spoleto PG 18 599 57006
Terni TR 18 111501 168507
Trevi PG 19 8469 176976
Cerreto di Spoleto PG 19 1075 178051
Giano dell'Umbria PG 19 3846 181897
San Gemini TR 19 5018 186915
Massa Martana PG 20 3770 190685

Municipalities with at least 50000 inhabitants

An earthquake occurred to
18 Km NE of Terni (111501 inhabitants)
28 Km S of Foligno (57155 inhabitants)
53 Km SE of Perugia (166134 inhabitants)
62 Km NE of Viterbo (67173 inhabitants)
67 Km NW of L'Aquila (69753 inhabitants)
79 Km W of Teramo (54892 inhabitants)
79 Km N of Guidonia Montecelio (88673 inhabitants)
83 Km N of Tivoli (56533 inhabitants)
93 Km N of Roma (2864731 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 3.1 1985-12-17
03:33:50
42.71 12.75 5 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 18239
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1985-12-17 03:33:50 ± 0.196
Latitude 42.71 ± 0.01
Longitude 12.75 ± 0.03
Depth (km) 5 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 18239

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) 2554.3
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 138
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 17
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.6
Epicentral distance of station closest to the epicenter (degree) 0.00291
Epicentral distance of station farthest from the epicenter (degree) 0.03489
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 12
Magnitude information

Md:3.1

Field Value
Value 3.1
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 18239
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:21:01
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.FO1.Z. 1985-12-17T03:34:51.00 10.0 undecidable manual PN 0 0.0349 0.43 0.7
--.RBL.Z. 1985-12-17T03:34:50.00 10.0 undecidable manual PN 8 0.0339 0.9 0.4
--.AM1.Z. 1985-12-17T03:34:26.96 10.0 undecidable manual SG 36 0.0094 0.03 1
--.RDP.Z. 1985-12-17T03:34:24.00 10.0 undecidable manual SG 181 0.0085 0.16 0.7
--.SGG.Z. 1985-12-17T03:34:22.30 10.0 undecidable manual PN 136 0.0161 0.39 1.2
--.DUI.Z. 1985-12-17T03:34:21.00 10.0 undecidable manual PN 129 0.0148 1.11 0.5
--.ARV.Z. 1985-12-17T03:34:19.00 10.0 undecidable manual SG 10 0.0072 -0.05 0.7
--.SD1.Z. 1985-12-17T03:34:15.50 10.0 undecidable manual PN 141 0.0114 0.74 1.1
--.AM1.Z. 1985-12-17T03:34:10.44 10.0 negative manual PG 36 0.0094 -1.07 1.4
--.PRG.Z. 1985-12-17T03:34:08.00 10.0 undecidable manual SG 326 0.0041 -0.31 0.9
--.RDP.Z. 1985-12-17T03:34:08.70 10.0 undecidable manual PG 181 0.0085 -1.03 0.7
--.ARV.Z. 1985-12-17T03:34:07.00 10.0 undecidable manual PG 10 0.0072 0.04 1.7
--.MNS.Z. 1985-12-17T03:34:02.80 10.0 undecidable manual SG 188 0.0029 -0.41 0.9
--.AQU.Z. 1985-12-17T03:34:02.50 10.0 undecidable manual PG 126 0.0053 -0.73 1.1
--.ASS.Z. 1985-12-17T03:34:00.00 10.0 undecidable manual PG 349 0.0032 1.51 0.3
--.PRG.Z. 1985-12-17T03:33:59.50 10.0 undecidable manual PG 326 0.0041 -1.26 0.5
--.MNS.Z. 1985-12-17T03:33:58.00 10.0 positive manual PG 188 0.0029 0.19 3.2
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
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