Earthquake with magnitude of Md 2.4 on date 25-04-1987 and time 23:28:51 (Italy) in region 4 km E San Gemini (TR)

A magnitude Md 2.4 earthquake occured in region: 4 km E San Gemini (TR), on

  • 25-04-1987 21:28:51 (UTC)
  • 25-04-1987 23:28:51 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.61, 12.59 at 26 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
San Gemini TR 4 5018 5018
Terni TR 7 111501 116519
Montecastrilli TR 10 5022 121541
Acquasparta TR 10 4778 126319
Narni TR 12 19785 146104
Stroncone TR 14 4917 151021
Montefranco TR 14 1276 152297
Avigliano Umbro TR 14 2558 154855
Arrone TR 15 2763 157618
Amelia TR 16 11897 169515
Ferentillo TR 16 1913 171428
Spoleto PG 19 38218 209646
Labro RI 19 374 210020
Massa Martana PG 20 3770 213790
Colli sul Velino RI 20 533 214323

Municipalities with at least 50000 inhabitants

An earthquake occurred to
7 Km NW of Terni (111501 inhabitants)
40 Km S of Foligno (57155 inhabitants)
45 Km E of Viterbo (67173 inhabitants)
58 Km S of Perugia (166134 inhabitants)
69 Km N of Guidonia Montecelio (88673 inhabitants)
72 Km W of L'Aquila (69753 inhabitants)
74 Km N of Tivoli (56533 inhabitants)
80 Km N of Roma (2864731 inhabitants)
87 Km NE of Civitavecchia (52991 inhabitants)
91 Km W of Teramo (54892 inhabitants)
97 Km NE of Fiumicino (78395 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 2.4 1987-04-25
21:28:51
42.61 12.59 26 2013-07-15
08:40:51
Bollettino Sismico Italiano INGV 45679
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-04-25 21:28:51 ± 0.312
Latitude 42.61 ± 0.01
Longitude 12.59 ± 0.07
Depth (km) 26 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 45679

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) 6028.4
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 201
Number of associated phases, regardless of their use for origin computation 10
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.3
Epicentral distance of station closest to the epicenter (degree) 0.00202
Epicentral distance of station farthest from the epicenter (degree) 0.01141
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitude information

Md:2.4

Field Value
Value 2.4
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 45679
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:44:58
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.SDI.Z. 1987-04-25T21:29:29.50 10.0 undecidable manual SN 134 0.0114 0.05 0.6
--.ARV.Z. 1987-04-25T21:29:22.00 10.0 undecidable manual SN 15 0.0083 0.8 0.2
--.CP9.Z. 1987-04-25T21:29:17.50 10.0 undecidable manual SN 160 0.0071 -0.52 0.4
--.SDI.Z. 1987-04-25T21:29:13.00 10.0 undecidable manual PN 134 0.0114 -0.55 0.7
--.ASS.Z. 1987-04-25T21:29:09.50 10.0 undecidable manual SG 5 0.004 0.14 1.2
--.ARV.Z. 1987-04-25T21:29:08.50 10.0 undecidable manual PN 15 0.0083 -0.28 1.5
--.CP9.Z. 1987-04-25T21:29:07.50 10.0 undecidable manual PN 160 0.0071 0.55 0.9
--.MNS.Z. 1987-04-25T21:29:03.50 10.0 undecidable manual SG 163 0.002 0.26 1.1
--.ASS.Z. 1987-04-25T21:29:01.50 10.0 undecidable manual PG 5 0.004 -0.45 1.2
--.MNS.Z. 1987-04-25T21:28:58.50 10.0 undecidable manual PG 163 0.002 0.08 2.1
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Download
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