Earthquake with magnitude of Md 2.0 on date 31-07-1991 and time 10:31:40 (UTC) in region 3 km E Vallo di Nera (PG)

A magnitude Md 2.0 earthquake occured in region: 3 km E Vallo di Nera (PG), on

  • 31-07-1991 10:31:40 (UTC)
  • 31-07-1991 12:31:40 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7800, 12.8950 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
Vallo di Nera PG 3 364 364
Cerreto di Spoleto PG 5 1075 1439
Sant'Anatolia di Narco PG 7 564 2003
Poggiodomo PG 8 117 2120
Scheggino PG 9 461 2581
Campello sul Clitunno PG 11 2442 5023
Cascia PG 12 3217 8240
Sellano PG 13 1079 9319
Spoleto PG 14 38218 47537
Monteleone di Spoleto PG 15 599 48136
Preci PG 16 724 48860
Trevi PG 16 8469 57329
Norcia PG 16 4957 62286
Castel Ritaldi PG 19 3278 65564
Ferentillo TR 20 1913 67477

Municipalities with at least 50000 inhabitants

An earthquake occurred to
25 Km SE of Foligno (57155 inhabitants)
32 Km NE of Terni (111501 inhabitants)
55 Km SE of Perugia (166134 inhabitants)
63 Km NW of L'Aquila (69753 inhabitants)
68 Km W of Teramo (54892 inhabitants)
76 Km NE of Viterbo (67173 inhabitants)
88 Km N of Guidonia Montecelio (88673 inhabitants)
91 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
Bulletin
Rev1000
Md 2.0 1991-07-31
10:31:40
42.78 12.895 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 146589
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-07-31 10:31:40 ± 0.258
Latitude 42.7800 ± 0.0118
Longitude 12.8950 ± 0.0397
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 146589

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) 3496.3
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 178
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) 0.6
Epicentral distance of station closest to the epicenter (degree) 0.00300
Epicentral distance of station farthest from the epicenter (degree) 0.00648
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:2.0

Field Value
Value 2.0
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 146589
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:16:49
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.ARV.Z. 1991-07-31T10:32:05.50 10.0 undecidable manual SG 2 0.7215 -0.43 0.6
--.CIO.Z. 1991-07-31T10:31:56.72 10.0 undecidable manual SG 23 0.444 -0.64 0.6
--.MNS.Z. 1991-07-31T10:31:55.74 10.0 undecidable manual SG 201 0.4218 -0.73 0.5
--.ARV.Z. 1991-07-31T10:31:54.78 10.0 undecidable manual PG 2 0.7215 -0.57 1.2
--.ASS.Z. 1991-07-31T10:31:53.11 10.0 undecidable manual SG 327 0.333 -0.43 0.6
--.CIO.Z. 1991-07-31T10:31:51.11 10.0 undecidable manual PG 23 0.444 0.7 1.3
--.ASS.Z. 1991-07-31T10:31:49.11 10.0 undecidable manual PG 327 0.333 0.91 1
--.MNS.Z. 1991-07-31T10:31:49.95 10.0 undecidable manual PG 201 0.4218 0.05 2.4
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