Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.3 on date 24-08-1991 and time 04:58:34 (Italy) in region Costa Ligure Occidentale (Imperia)

A magnitude Md 2.3 earthquake occured in region: Costa Ligure Occidentale (Imperia), on

  • 24-08-1991 02:58:34 (UTC)
  • 24-08-1991 04:58:34 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.6900, 7.7740 at 21 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
Bordighera IM 13 10469 10469
Ospedaletti IM 13 3367 13836
Sanremo IM 15 54807 68643
Vallecrosia IM 16 6956 75599
Vallebona IM 16 1310 76909
Seborga IM 17 315 77224
Ventimiglia IM 17 24310 101534
San Biagio della Cima IM 18 1329 102863
Soldano IM 18 977 103840
Camporosso IM 18 5632 109472
Taggia IM 18 14116 123588
Riva Ligure IM 19 2910 126498
Santo Stefano al Mare IM 19 2197 128695

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km S of Sanremo (54807 inhabitants)
80 Km S of Cuneo (56081 inhabitants)
89 Km SW of Savona (61345 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 2.3
M 2.4 		1991-08-24
02:58:34		 43.69 7.774 21 2013-07-15
08:40:51		 Bollettino Sismico Italiano INGV 148059
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-08-24 02:58:34 ± 0.364
Latitude 43.6900 ± 0.0218
Longitude 7.7740 ± 0.0259
Depth (km) 21 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 148059

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) 3195.7
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 108
Number of associated phases, regardless of their use for origin computation 26
Number of defining phases 26
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.5
Epicentral distance of station closest to the epicenter (degree) 0.00210
Epicentral distance of station farthest from the epicenter (degree) 0.01303
Number of stations at which the event was observed 14
Number of stations from which data was used for origin computation 14
Magnitudes information

Md:2.3

Field Value
Value 2.3
Uncertainty
Num. used stations 1
Type of magnitude Md
Reference to an origin 148059
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:18:11

M:2.4

Field Value
Value 2.4
Uncertainty
Num. used stations
Type of magnitude M
Reference to an origin 148059
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
--.LRG.Z. 1991-08-24T02:59:07.50 10.0 undecidable manual SN 257 1.0434 -0.44 0.6
--.PCP.Z. 1991-08-24T02:59:07.79 10.0 undecidable manual SN 32 1.0101 0.69 0.5
--.LMR.Z. 1991-08-24T02:59:04.80 10.0 undecidable manual SN 249 0.9768 -1.55 0.1
--.PZZ.Z. 1991-08-24T02:59:04.92 10.0 undecidable manual SN 329 0.9435 -0.57 0.5
--.DOI.Z. 1991-08-24T02:59:03.50 10.0 undecidable manual SN 335 0.888 -0.81 0.4
--.FRF.Z. 1991-08-24T02:59:01.60 10.0 undecidable manual SN 261 0.8214 -1 0.3
--.PGF.Z. 1991-08-24T02:58:58.40 10.0 undecidable manual PN 141 1.443 -1.27 0.3
--.STV.Z. 1991-08-24T02:58:56.31 10.0 undecidable manual SG 330 0.6327 -1.17 0.2
--.BHB.Z. 1991-08-24T02:58:56.20 10.0 undecidable manual PN 342 1.1988 0.3 1.5
--.ENR.Z. 1991-08-24T02:58:55.70 10.0 undecidable manual SG 334 0.5883 -0.77 0.5
--.ROB.Z. 1991-08-24T02:58:55.17 10.0 undecidable manual SG 6 0.6105 -1.38 0.1
--.PCP.Z. 1991-08-24T02:58:54.77 10.0 undecidable manual PN 32 1.0101 1.42 0.3
--.FIN.Z. 1991-08-24T02:58:54.66 10.0 undecidable manual SG 31 0.5994 -1.55 0.1
--.LRG.Z. 1991-08-24T02:58:54.60 10.0 undecidable manual PN 257 1.0434 0.77 1
--.LMR.Z. 1991-08-24T02:58:53.00 10.0 undecidable manual PN 249 0.9768 0.08 1.8
--.DOI.Z. 1991-08-24T02:58:52.00 10.0 undecidable manual PN 335 0.888 0.26 1.8
--.PZZ.Z. 1991-08-24T02:58:52.92 10.0 undecidable manual PN 329 0.9435 0.5 1.5
--.FRF.Z. 1991-08-24T02:58:50.90 10.0 undecidable manual PN 261 0.8214 0.15 1.9
--.STV.Z. 1991-08-24T02:58:48.00 10.0 undecidable manual PG 330 0.6327 0.21 2
--.ENR.Z. 1991-08-24T02:58:47.18 10.0 undecidable manual PG 334 0.5883 0.33 1.8
--.SBF.Z. 1991-08-24T02:58:47.00 10.0 undecidable manual SG 305 0.2997 0.15 0.8
--.ROB.Z. 1991-08-24T02:58:47.28 10.0 undecidable manual PG 6 0.6105 0.02 2.1
--.FIN.Z. 1991-08-24T02:58:46.87 10.0 undecidable manual PG 31 0.5994 -0.19 2
--.IMI.Z. 1991-08-24T02:58:44.72 10.0 undecidable manual SG 21 0.2331 -0.37 0.7
--.SBF.Z. 1991-08-24T02:58:42.30 10.0 undecidable manual PG 305 0.2997 0.64 1.4
--.IMI.Z. 1991-08-24T02:58:40.93 10.0 undecidable manual PG 21 0.2331 0.29 1.9
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