Earthquake with magnitude of Md 2.1 on date 22-05-1987 and time 11:31:40 (Italy) in region 4 km NW Trevi (PG)

A magnitude Md 2.1 earthquake occured in region: 4 km NW Trevi (PG), on

  • 22-05-1987 09:31:40 (UTC)
  • 22-05-1987 11:31:40 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.9050, 12.7190 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
Trevi PG 4 8469 8469
Montefalco PG 6 5679 14148
Foligno PG 6 57155 71303
Bevagna PG 10 5081 76384
Castel Ritaldi PG 10 3278 79662
Campello sul Clitunno PG 11 2442 82104
Spello PG 11 8645 90749
Gualdo Cattaneo PG 13 6155 96904
Giano dell'Umbria PG 14 3846 100750
Cannara PG 15 4305 105055
Sellano PG 17 1079 106134
Valtopina PG 18 1398 107532
Cerreto di Spoleto PG 19 1075 108607
Spoleto PG 19 38218 146825
Vallo di Nera PG 19 364 147189

Municipalities with at least 50000 inhabitants

An earthquake occurred to
6 Km S of Foligno (57155 inhabitants)
35 Km SE of Perugia (166134 inhabitants)
39 Km N of Terni (111501 inhabitants)
74 Km NE of Viterbo (67173 inhabitants)
83 Km NW of L'Aquila (69753 inhabitants)
85 Km W of Teramo (54892 inhabitants)
92 Km SE of Arezzo (99543 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 1987-05-22
09:31:40
42.905 12.719 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 47529
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-05-22 09:31:40 ± 0.235
Latitude 42.9050 ± 0.0115
Longitude 12.7190 ± 0.0139
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 47529

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) 1706.4
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 241
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) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00146
Epicentral distance of station farthest from the epicenter (degree) 0.00567
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 1
Type of magnitude Md
Reference to an origin 47529
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:46:34
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.ALP.Z. 1987-05-22T09:32:03.33 10.0 undecidable manual SG 100 0.6327 0.27 0.3
--.CM8.Z. 1987-05-22T09:31:56.41 10.0 undecidable manual SG 46 0.4218 0.07 0.9
--.ALP.Z. 1987-05-22T09:31:53.63 10.0 undecidable manual PG 100 0.6327 -0.02 1.6
--.CM8.Z. 1987-05-22T09:31:49.17 10.0 undecidable manual PG 46 0.4218 -0.59 0.4
--.ASS.Z. 1987-05-22T09:31:48.00 10.0 undecidable manual SG 342 0.1665 0.01 0.8
--.ASS.Z. 1987-05-22T09:31:45.00 10.0 undecidable manual PG 342 0.1665 0.05 2
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