Earthquake with magnitude of Md 2.5 on date 21-09-1987 and time 20:16:47 (Italy) in region 8 km N Gubbio (PG)

A magnitude Md 2.5 earthquake occured in region: 8 km N Gubbio (PG), on

  • 21-09-1987 18:16:47 (UTC)
  • 21-09-1987 20:16:47 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.4230, 12.5620 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
Gubbio PG 8 32216 32216
Cantiano PU 8 2245 34461
Scheggia e Pascelupo PG 9 1393 35854
Pietralunga PG 10 2111 37965
Costacciaro PG 14 1216 39181
Cagli PU 16 8731 47912
Sigillo PG 18 2404 50316
Frontone PU 18 1300 51616
Serra Sant'Abbondio PU 19 1027 52643
Apecchio PU 19 1882 54525
Piobbico PU 19 2029 56554

Municipalities with at least 50000 inhabitants

An earthquake occurred to
38 Km NE of Perugia (166134 inhabitants)
53 Km N of Foligno (57155 inhabitants)
55 Km E of Arezzo (99543 inhabitants)
60 Km SW of Fano (60888 inhabitants)
61 Km SW of Pesaro (94582 inhabitants)
71 Km S of Rimini (147750 inhabitants)
80 Km W of Ancona (100861 inhabitants)
84 Km SE of Cesena (96758 inhabitants)
96 Km N of Terni (111501 inhabitants)
98 Km SE of Forlì (117913 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
ML-VAX 1.8
1987-09-21
18:16:47
43.423 12.562 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 55809
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-09-21 18:16:47 ± 0.528
Latitude 43.4230 ± 0.0237
Longitude 12.5620 ± 0.0361
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 55809

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) 3931.4
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 234
Number of associated phases, regardless of their use for origin computation 7
Number of defining phases 7
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.4
Epicentral distance of station closest to the epicenter (degree) 0.00251
Epicentral distance of station farthest from the epicenter (degree) 0.00429
Number of stations at which the event was observed 4
Number of stations from which data was used for origin computation 4
Magnitudes information

Md:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 55809
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:53:40

ML:1.8

Field Value
Value 1.8
Uncertainty
Num. used stations 1
Type of magnitude ML
Reference to an origin 55809
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(km) Takeoff_angle Residual Weight
--.CM8.Z. 1987-09-21T18:17:06.70 10.0 undecidable manual SG 118 0.4773 0.85 0.3
--.ASS.Z. 1987-09-21T18:17:01.60 10.0 undecidable manual SG 169 0.3552 -0.48 0.5
--.ARV.Z. 1987-09-21T18:16:58.73 10.0 undecidable manual SG 74 0.2775 -0.28 0.7
--.CM8.Z. 1987-09-21T18:16:57.64 10.0 undecidable manual PG 118 0.4773 -0.24 1.6
--.PRG.Z. 1987-09-21T18:16:56.00 10.0 undecidable manual PG 200 0.3441 0.66 0.9
--.ASS.Z. 1987-09-21T18:16:55.10 10.0 undecidable manual PG 169 0.3552 -0.66 0.9
--.ARV.Z. 1987-09-21T18:16:54.31 10.0 undecidable manual PG 74 0.2775 0.02 2
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
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QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download