Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.2 on date 04-08-1987 and time 12:13:21 (Italy) in region 3 km N Rialto (SV)

A magnitude Md 2.2 earthquake occured in region: 3 km N Rialto (SV), on

  • 04-08-1987 10:13:21 (UTC)
  • 04-08-1987 12:13:21 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.2500, 8.2770 at 12 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.

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Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Rialto SV 3 564 564
Bormida SV 5 387 951
Mallare SV 5 1146 2097
Orco Feglino SV 5 890 2987
Calice Ligure SV 5 1730 4717
Magliolo SV 7 974 5691
Osiglia SV 7 444 6135
Vezzi Portio SV 7 809 6944
Tovo San Giacomo SV 8 2582 9526
Pallare SV 9 923 10449
Giustenice SV 9 977 11426
Borgio Verezzi SV 10 2205 13631
Finale Ligure SV 10 11711 25342
Altare SV 11 2108 27450
Pietra Ligure SV 11 8992 36442
Spotorno SV 12 3803 40245
Murialdo SV 12 841 41086
Quiliano SV 12 7232 48318
Carcare SV 12 5587 53905
Plodio SV 12 650 54555
Noli SV 12 2736 57291
Calizzano SV 13 1475 58766
Vado Ligure SV 13 8336 67102
Bardineto SV 13 756 67858
Bergeggi SV 13 1129 68987
Loano SV 13 11407 80394
Boissano SV 14 2492 82886
Cosseria SV 14 1105 83991
Millesimo SV 14 3383 87374
Roccavignale SV 14 752 88126
Toirano SV 15 2644 90770
Borghetto Santo Spirito SV 15 4948 95718
Balestrino SV 16 595 96313
Cengio SV 16 3563 99876
Castelnuovo di Ceva CN 16 110 99986
Cairo Montenotte SV 17 13269 113255
Massimino SV 17 113 113368
Ceriale SV 17 5561 118929
Savona SV 18 61345 180274
Montezemolo CN 18 259 180533
Perlo CN 18 116 180649
Castelvecchio di Rocca Barbena SV 18 145 180794
Erli SV 19 245 181039
Bagnasco CN 20 1035 182074
Zuccarello SV 20 309 182383

Municipalities with at least 50000 inhabitants

An earthquake occurred to
18 Km W of Savona (61345 inhabitants)
55 Km W of Genova (586655 inhabitants)
60 Km E of Cuneo (56081 inhabitants)
62 Km NE of Sanremo (54807 inhabitants)
73 Km S of Asti (76202 inhabitants)
79 Km SW of Alessandria (93943 inhabitants)
96 Km SE of Moncalieri (57294 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 2.2
M 2.5 		1987-08-04
10:13:21		 44.25 8.277 12 2013-07-15
08:40:51		 Bollettino Sismico Italiano INGV 53389
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-08-04 10:13:21 ± 0.437
Latitude 44.2500 ± 0.0128
Longitude 8.2770 ± 0.0312
Depth (km) 12 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 53389

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) 2862.1
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 289
Number of associated phases, regardless of their use for origin computation 9
Number of defining phases 9
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) 0.00057
Epicentral distance of station farthest from the epicenter (degree) 0.00785
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitudes information

Md:2.2

Field Value
Value 2.2
Uncertainty
Num. used stations 1
Type of magnitude Md
Reference to an origin 53389
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:51:30

M:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations
Type of magnitude M
Reference to an origin 53389
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 09:48:29
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.DOI.Z. 1987-08-04T10:13:47.50 10.0 undecidable manual SG 289 0.777 -0.63 0.1
--.PZZ.Z. 1987-08-04T10:13:38.70 10.0 undecidable manual PG 287 0.8769 0.15 1.3
--.DOI.Z. 1987-08-04T10:13:37.00 10.0 undecidable manual PG 289 0.777 0.27 1.1
--.IMI.Z. 1987-08-04T10:13:37.40 10.0 undecidable manual SG 219 0.4329 0.26 0.6
--.ROB.Z. 1987-08-04T10:13:32.40 10.0 undecidable manual SG 280 0.2886 -0.16 0.8
--.IMI.Z. 1987-08-04T10:13:30.20 10.0 undecidable manual PG 219 0.4329 -0.19 1.8
--.ROB.Z. 1987-08-04T10:13:27.90 10.0 undecidable manual PG 280 0.2886 0.15 2
--.FIN.Z. 1987-08-04T10:13:26.50 10.0 undecidable manual SG 229 0.0666 0.52 0.2
--.FIN.Z. 1987-08-04T10:13:23.60 10.0 undecidable manual PG 229 0.0666 -0.34 1.1
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