Earthquake with magnitude of Md 2.5 on date 21-09-1987 and time 21:09:09 (Italy) in region Confine Italia Svizzera (SVIZZERA)

A magnitude Md 2.5 earthquake occured in region: Confine Italia Svizzera (SVIZZERA), on

  • 21-09-1987 19:09:09 (UTC)
  • 21-09-1987 21:09:09 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 46.1140, 7.9350 at 5 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
Antrona Schieranco VB 15 428 428
Macugnaga VB 16 557 985
Ceppo Morelli VB 19 321 1306

Municipalities with at least 50000 inhabitants

An earthquake occurred to
76 Km W of Varese (80799 inhabitants)
83 Km NW of Gallarate (53343 inhabitants)
90 Km NW of Busto Arsizio (83106 inhabitants)
91 Km NW of Novara (104380 inhabitants)
95 Km W of Como (84495 inhabitants)
96 Km NW of Legnano (60262 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 1.6
1987-09-21
19:09:09
46.114 7.935 5 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 55819
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-09-21 19:09:09 ± 0.148
Latitude 46.1140 ± 0.0087
Longitude 7.9350 ± 0.0180
Depth (km) 5 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 55819

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) 1691.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 136
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) 0.00437
Epicentral distance of station farthest from the epicenter (degree) 0.01538
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 3
Type of magnitude Md
Reference to an origin 55819
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:53:40

ML:1.6

Field Value
Value 1.6
Uncertainty
Num. used stations 3
Type of magnitude ML
Reference to an origin 55819
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
--.ROF.Z. 1987-09-21T19:09:40.00 10.0 undecidable manual PN 336 1.7094 0.17 1.2
--.BNI.Z. 1987-09-21T19:09:34.95 10.0 undecidable manual PN 220 1.3764 -0.22 1.3
--.VAI.Z. 1987-09-21T19:09:33.00 10.0 undecidable manual SG 112 0.6327 0.46 0.2
--.ORO.Z. 1987-09-21T19:09:28.00 10.0 undecidable manual SG 176 0.4884 0.07 0.9
--.VAI.Z. 1987-09-21T19:09:22.37 10.0 undecidable manual PG 112 0.6327 -0.4 0.8
--.ORO.Z. 1987-09-21T19:09:20.32 10.0 undecidable manual PG 176 0.4884 0.21 1.6
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