Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.3 on date 08-10-1991 and time 19:30:50 (UTC) in region 4 km N Valtournenche (AO)

A magnitude Md 2.3 earthquake occured in region: 4 km N Valtournenche (AO), on

  • 08-10-1991 19:30:50 (UTC)
  • 08-10-1991 20:30:50 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 45.9130, 7.6380 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.

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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
Valtournenche AO 4 2277 2277
Chamois AO 8 97 2374
La Magdeleine AO 11 109 2483
Ayas AO 12 1401 3884
Antey-Saint-André AO 12 602 4486
Torgnon AO 13 558 5044
Bionaz AO 17 236 5280
Gressoney-La-Trinité AO 17 303 5583
Saint-Vincent AO 18 4660 10243
Châtillon AO 18 4772 15015
Brusson AO 19 897 15912
Verrayes AO 19 1302 17214
Saint-Denis AO 19 378 17592
Pontey AO 20 817 18409
Chambave AO 20 931 19340

Municipalities with at least 50000 inhabitants

An earthquake occurred to
92 Km NW of Novara (104380 inhabitants)
92 Km W of Varese (80799 inhabitants)
93 Km N of Torino (890529 inhabitants)
94 Km W of Gallarate (53343 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 2.5 		1991-10-08
19:30:50		 45.913 7.638 5 2013-07-15
08:41:04		 Bollettino Sismico Italiano INGV 150709
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-10-08 19:30:50 ± 0.299
Latitude 45.9130 ± 0.0207
Longitude 7.6380 ± 0.0250
Depth (km) 5 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 150709

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) 3003.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 101
Number of associated phases, regardless of their use for origin computation 20
Number of defining phases 20
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.8
Epicentral distance of station closest to the epicenter (degree) 0.00202
Epicentral distance of station farthest from the epicenter (degree) 0.03036
Number of stations at which the event was observed 15
Number of stations from which data was used for origin computation 15
Magnitudes information

Md:2.3

Field Value
Value 2.3
Uncertainty
Num. used stations 1
Type of magnitude Md
Reference to an origin 150709
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:20:39

M:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations
Type of magnitude M
Reference to an origin 150709
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 09:42:56
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.BGF.Z. 1991-10-08T19:31:44.40 10.0 undecidable manual PN 282 3.3744 1.21 0.5
--.AVF.Z. 1991-10-08T19:31:40.00 10.0 undecidable manual PN 287 3.0747 0.8 0.8
--.LOR.Z. 1991-10-08T19:31:38.80 10.0 undecidable manual PN 298 2.9193 1.73 0.3
--.LBF.Z. 1991-10-08T19:31:36.00 10.0 undecidable manual PN 294 2.7306 1.53 0.4
--.SMF.Z. 1991-10-08T19:31:34.00 10.0 undecidable manual PN 286 2.7084 -0.25 1.1
--.PZZ.Z. 1991-10-08T19:31:18.00 10.0 undecidable manual PN 195 1.443 1.13 1
--.RSP.Z. 1991-10-08T19:31:17.00 10.0 undecidable manual SG 199 0.7992 -1.77 0.2
--.LPL.Z. 1991-10-08T19:31:14.40 10.0 undecidable manual SG! 238 0.7326 -2.45 0
--.LSD.Z. 1991-10-08T19:31:09.90 10.0 undecidable manual SG 216 0.555 -1.16 0.4
--.TMA.Z. 1991-10-08T19:31:07.40 10.0 undecidable manual PG 76 0.8769 -0.57 1.7
--.RSP.Z. 1991-10-08T19:31:06.70 10.0 undecidable manual PG 199 0.7992 0.08 1.9
--.LPL.Z. 1991-10-08T19:31:05.00 10.0 undecidable manual PG 238 0.7326 -0.52 1.7
--.ORX.Z. 1991-10-08T19:31:04.90 10.0 undecidable manual SG 139 0.3552 0.58 0.7
--.ORO.Z. 1991-10-08T19:31:03.00 10.0 undecidable manual SG 139 0.3663 -1.46 0.3
--.LSD.Z. 1991-10-08T19:31:01.60 10.0 undecidable manual PG 216 0.555 -0.58 1.7
--.EMS.Z. 1991-10-08T19:30:59.70 10.0 undecidable manual PG 287 0.5106 -1.54 0.7
--.ORO.Z. 1991-10-08T19:30:59.00 10.0 undecidable manual PG 139 0.3663 0.63 1.6
--.ORX.Z. 1991-10-08T19:30:58.70 10.0 undecidable manual PG 139 0.3552 0.42 1.8
--.MMK.Z. 1991-10-08T19:30:55.30 10.0 undecidable manual PG 58 0.2553 -0.73 1.5
--.DIX.Z. 1991-10-08T19:30:53.40 10.0 undecidable manual PG 316 0.222 -1.85 0.4
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