Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.2 on date 14-08-1991 and time 12:40:31 (UTC) in region 3 km W Montespertoli (FI)

A magnitude Md 2.2 earthquake occured in region: 3 km W Montespertoli (FI), on

  • 14-08-1991 12:40:31 (UTC)
  • 14-08-1991 14:40:31 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.6570, 11.0420 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.

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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
Montespertoli FI 3 13537 13537
Castelfiorentino FI 8 17504 31041
Montelupo Fiorentino FI 8 14098 45139
Empoli FI 10 48109 93248
Capraia e Limite FI 11 7670 100918
San Casciano in Val di Pesa FI 12 17062 117980
Certaldo FI 12 16121 134101
Lastra a Signa FI 14 20156 154257
Signa FI 15 19179 173436
Gambassi Terme FI 15 4870 178306
Tavarnelle Val di Pesa FI 15 7800 186106
San Miniato PI 15 27934 214040
Montaione FI 16 3700 217740
Scandicci FI 16 50609 268349
Barberino Val d'Elsa FI 17 4386 272735
Vinci FI 17 14604 287339
Impruneta FI 18 14615 301954
Cerreto Guidi FI 18 10870 312824
Carmignano PO 18 14450 327274
Poggio a Caiano PO 18 10007 337281
Campi Bisenzio FI 20 46166 383447

Municipalities with at least 50000 inhabitants

An earthquake occurred to
16 Km SW of Scandicci (50609 inhabitants)
21 Km SW of Firenze (382808 inhabitants)
25 Km S of Prato (191150 inhabitants)
32 Km SE of Pistoia (90315 inhabitants)
44 Km NW of Siena (53903 inhabitants)
48 Km E of Lucca (89046 inhabitants)
52 Km E of Pisa (89158 inhabitants)
60 Km E of Livorno (159219 inhabitants)
68 Km E of Viareggio (62467 inhabitants)
71 Km W of Arezzo (99543 inhabitants)
84 Km SE of Massa (69479 inhabitants)
89 Km SE of Carrara (63133 inhabitants)
94 Km SW of Imola (69797 inhabitants)
96 Km S of Bologna (386663 inhabitants)
97 Km SW of Faenza (58541 inhabitants)
100 Km N of Grosseto (82087 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
ML-VAX 1.9 		1991-08-14
12:40:31		 43.657 11.042 10 2013-07-15
08:41:04		 Bollettino Sismico Italiano INGV 147399
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-08-14 12:40:31 ± 0.328
Latitude 43.6570 ± 0.0261
Longitude 11.0420 ± 0.0151
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 147399

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) 3140.3
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 213
Number of associated phases, regardless of their use for origin computation 10
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.4
Epicentral distance of station closest to the epicenter (degree) 0.00340
Epicentral distance of station farthest from the epicenter (degree) 0.00567
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 4
Type of magnitude Md
Reference to an origin 147399
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:17:35

ML:1.9

Field Value
Value 1.9
Uncertainty
Num. used stations 3
Type of magnitude ML
Reference to an origin 147399
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
--.SFI.Z. 1991-08-14T12:40:53.59 10.0 undecidable manual SG 66 0.6327 -0.58 0.3
--.MME.Z. 1991-08-14T12:40:53.22 10.0 undecidable manual SG 335 0.5883 0.38 0.7
--.PGD.Z. 1991-08-14T12:40:51.00 10.0 undecidable manual SG 65 0.5328 -0.12 0.7
--.BDI.Z. 1991-08-14T12:40:49.93 10.0 undecidable manual SG 321 0.5106 -0.55 0.4
--.PII.Z. 1991-08-14T12:40:45.15 10.0 undecidable manual SG 279 0.3774 -0.93 0.2
--.MME.Z. 1991-08-14T12:40:45.22 10.0 undecidable manual PG 335 0.5883 1.2 0.3
--.SFI.Z. 1991-08-14T12:40:44.37 10.0 undecidable manual PG 66 0.6327 -0.41 1.2
--.PGD.Z. 1991-08-14T12:40:43.70 10.0 undecidable manual PG 65 0.5328 0.67 1.1
--.BDI.Z. 1991-08-14T12:40:42.25 10.0 undecidable manual PG 321 0.5106 -0.41 1.3
--.PII.Z. 1991-08-14T12:40:40.21 10.0 negative manual PG 279 0.3774 0.09 3.7
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