Earthquake with magnitude of Md 2.1 on date 21-04-1985 and time 07:49:24 (Italy) in region 3 km NW Spoleto (PG)

A magnitude Md 2.1 earthquake occured in region: 3 km NW Spoleto (PG), on

  • 21-04-1985 05:49:24 (UTC)
  • 21-04-1985 07:49:24 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7570, 12.7200 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
Spoleto PG 3 38218 38218
Castel Ritaldi PG 8 3278 41496
Campello sul Clitunno PG 9 2442 43938
Sant'Anatolia di Narco PG 10 564 44502
Scheggino PG 10 461 44963
Vallo di Nera PG 12 364 45327
Trevi PG 14 8469 53796
Giano dell'Umbria PG 14 3846 57642
Acquasparta TR 16 4778 62420
Ferentillo TR 16 1913 64333
Massa Martana PG 16 3770 68103
Montefalco PG 16 5679 73782
Cerreto di Spoleto PG 18 1075 74857
Montefranco TR 18 1276 76133
Poggiodomo PG 18 117 76250
Arrone TR 20 2763 79013

Municipalities with at least 50000 inhabitants

An earthquake occurred to
22 Km S of Foligno (57155 inhabitants)
23 Km N of Terni (111501 inhabitants)
47 Km SE of Perugia (166134 inhabitants)
63 Km NE of Viterbo (67173 inhabitants)
72 Km NW of L'Aquila (69753 inhabitants)
81 Km W of Teramo (54892 inhabitants)
84 Km N of Guidonia Montecelio (88673 inhabitants)
88 Km N of Tivoli (56533 inhabitants)
98 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
Bulletin
Rev1000
Md 2.1 1985-04-21
05:49:24
42.757 12.72 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 5069
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1985-04-21 05:49:24 ± 0.648
Latitude 42.7570 ± 0.0284
Longitude 12.7200 ± 0.0788
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 5069

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) 7171.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 212
Number of associated phases, regardless of their use for origin computation 6
Number of defining phases 6
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) 0.00219
Epicentral distance of station farthest from the epicenter (degree) 0.00478
Number of stations at which the event was observed 3
Number of stations from which data was used for origin computation 3
Magnitude information

Md:2.1

Field Value
Value 2.1
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 5069
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:09:34
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.CM2.Z. 1985-04-21T05:49:42.90 10.0 undecidable manual SG 35 0.5328 -0.73 0.5
--.CM2.Z. 1985-04-21T05:49:37.70 10.0 undecidable manual PG 35 0.5328 2.12 0.4
--.AS1.Z. 1985-04-21T05:49:36.00 10.0 undecidable manual SG 350 0.3108 -0.43 0.6
--.PO9.Z. 1985-04-21T05:49:34.50 10.0 undecidable manual SG 138 0.2442 0.14 0.8
--.AS1.Z. 1985-04-21T05:49:31.50 10.0 undecidable manual PG 350 0.3108 0.07 2
--.PO9.Z. 1985-04-21T05:49:30.00 10.0 undecidable manual PG 138 0.2442 -0.23 1.8
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