Earthquake with magnitude of Md 2.5 on date 21-10-1987 and time 15:31:25 (Italy) in region 5 km SW Frontone (PU)

A magnitude Md 2.5 earthquake occured in region: 5 km SW Frontone (PU), on

  • 21-10-1987 14:31:25 (UTC)
  • 21-10-1987 15:31:25 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.4800, 12.7100 at 29 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
Frontone PU 5 1300 1300
Serra Sant'Abbondio PU 5 1027 2327
Cantiano PU 7 2245 4572
Scheggia e Pascelupo PG 9 1393 5965
Cagli PU 9 8731 14696
Sassoferrato AN 13 7285 21981
Costacciaro PG 13 1216 23197
Pergola PU 14 6333 29530
Acqualagna PU 16 4393 33923
Sigillo PG 17 2404 36327
Gubbio PG 18 32216 68543
Arcevia AN 19 4612 73155
Genga AN 19 1797 74952

Municipalities with at least 50000 inhabitants

An earthquake occurred to
48 Km SW of Fano (60888 inhabitants)
49 Km NE of Perugia (166134 inhabitants)
51 Km SW of Pesaro (94582 inhabitants)
58 Km N of Foligno (57155 inhabitants)
66 Km S of Rimini (147750 inhabitants)
67 Km E of Arezzo (99543 inhabitants)
67 Km W of Ancona (100861 inhabitants)
82 Km SE of Cesena (96758 inhabitants)
99 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 1.9
1987-10-21
14:31:25
43.48 12.71 29 2013-07-15
08:40:51
Bollettino Sismico Italiano INGV 57369
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-10-21 14:31:25 ± 0.244
Latitude 43.4800 ± 0.0228
Longitude 12.7100 ± 0.0307
Depth (km) 29 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 57369

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) 3545.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 137
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 13
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) 0.00154
Epicentral distance of station farthest from the epicenter (degree) 0.00842
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitudes information

Md:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations 4
Type of magnitude Md
Reference to an origin 57369
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:55:01

ML:1.9

Field Value
Value 1.9
Uncertainty
Num. used stations 4
Type of magnitude ML
Reference to an origin 57369
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
--.PGD.Z. 1987-10-21T14:31:53.14 10.0 undecidable manual SN 299 0.8103 1.11 0.1
--.SS9.Z. 1987-10-21T14:31:51.86 10.0 undecidable manual SN 305 0.7548 1.16 0.1
--.AM8.Z. 1987-10-21T14:31:49.45 10.0 undecidable manual SN 83 0.6438 1.38 0
--.CRE.Z. 1987-10-21T14:31:45.30 10.0 undecidable manual SN 284 0.5661 -0.81 0.3
--.ALP.Z. 1987-10-21T14:31:43.00 10.0 undecidable manual PN 138 0.9324 0.38 0.9
--.ASS.Z. 1987-10-21T14:31:42.30 10.0 undecidable manual SG 185 0.4107 -0.28 0.5
--.PGD.Z. 1987-10-21T14:31:40.50 10.0 undecidable manual PN 299 0.8103 -0.45 0.9
--.SS9.Z. 1987-10-21T14:31:39.70 10.0 undecidable manual PN 305 0.7548 -0.48 0.9
--.CRE.Z. 1987-10-21T14:31:37.00 10.0 undecidable manual PN 284 0.5661 -0.52 1
--.AM8.Z. 1987-10-21T14:31:37.55 10.0 undecidable manual PN 83 0.6438 -1.11 0.2
--.ASS.Z. 1987-10-21T14:31:35.46 10.0 positive manual PG 185 0.4107 -0.03 2.8
--.CM8.Z. 1987-10-21T14:31:35.21 10.0 positive manual PN 132 0.4218 -0.37 2.3
--.ARV.Z. 1987-10-21T14:31:31.95 10.0 positive manual PG 83 0.1665 0.01 2.9
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
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