Earthquake with magnitude of Md 2.2 on date 18-05-1991 and time 05:31:02 (Italy) in region 1 km NW Castelfiorentino (FI)

A magnitude Md 2.2 earthquake occured in region: 1 km NW Castelfiorentino (FI), on

  • 18-05-1991 03:31:02 (UTC)
  • 18-05-1991 05:31:02 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.6170, 10.9630 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Castelfiorentino FI 1 17504 17504
Montaione FI 8 3700 21204
Gambassi Terme FI 9 4870 26074
Montespertoli FI 10 13537 39611
Certaldo FI 10 16121 55732
San Miniato PI 11 27934 83666
Empoli FI 12 48109 131775
Montelupo Fiorentino FI 14 14098 145873
Capraia e Limite FI 14 7670 153543
Palaia PI 15 4612 158155
Montopoli in Val d'Arno PI 17 11148 169303
Cerreto Guidi FI 17 10870 180173
Fucecchio FI 18 23618 203791
San Gimignano SI 18 7820 211611
Tavarnelle Val di Pesa FI 18 7800 219411
Santa Croce sull'Arno PI 18 14601 234012
San Casciano in Val di Pesa FI 19 17062 251074
Barberino Val d'Elsa FI 19 4386 255460
Vinci FI 19 14604 270064
Castelfranco di Sotto PI 20 13427 283491

Municipalities with at least 50000 inhabitants

An earthquake occurred to
24 Km SW of Scandicci (50609 inhabitants)
29 Km SW of Firenze (382808 inhabitants)
31 Km SW of Prato (191150 inhabitants)
36 Km S of Pistoia (90315 inhabitants)
45 Km NW of Siena (53903 inhabitants)
45 Km SE of Lucca (89046 inhabitants)
46 Km E of Pisa (89158 inhabitants)
53 Km E of Livorno (159219 inhabitants)
64 Km E of Viareggio (62467 inhabitants)
76 Km W of Arezzo (99543 inhabitants)
81 Km SE of Massa (69479 inhabitants)
86 Km SE of Carrara (63133 inhabitants)
96 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 1991-05-18
03:31:02
43.617 10.963 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 141429
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-05-18 03:31:02 ± 0.382
Latitude 43.6170 ± 0.0272
Longitude 10.9630 ± 0.0148
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 141429

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) 3249.7
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 222
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) 0.00235
Epicentral distance of station farthest from the epicenter (degree) 0.00623
Number of stations at which the event was observed 7
Number of stations from which data was used for origin computation 7
Magnitude information

Md:2.2

Field Value
Value 2.2
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 141429
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:12:01
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.SFI.Z. 1991-05-18T03:31:25.94 10.0 undecidable manual SG 65 0.6882 -0.59 0.3
--.BDI.Z. 1991-05-18T03:31:20.20 10.0 undecidable manual SG 329 0.5106 -0.45 0.5
--.PGD.Z. 1991-05-18T03:31:15.18 10.0 undecidable manual PG 64 0.5994 0.72 0.6
--.MME.Z. 1991-05-18T03:31:15.00 10.0 undecidable manual PG 342 0.5994 0.52 1
--.SFI.Z. 1991-05-18T03:31:15.93 10.0 undecidable manual PG 65 0.6882 -0.29 1.4
--.PII.Z. 1991-05-18T03:31:14.60 10.0 undecidable manual SG 288 0.333 -0.7 0.3
--.BDI.Z. 1991-05-18T03:31:12.68 10.0 undecidable manual PG 329 0.5106 -0.14 1.8
--.PTF.Z. 1991-05-18T03:31:10.10 10.0 undecidable manual PG 12 0.3441 0.36 1.5
--.PII.Z. 1991-05-18T03:31:09.56 10.0 undecidable manual PG 288 0.333 0.14 1.9
--.FIR.Z. 1991-05-18T03:31:07.50 10.0 undecidable manual PG 53 0.2553 -0.61 0.9
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
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QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download