Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.2 on date 18-09-2021 and time 05:56:39 (UTC) in region 6 km S Montieri (GR)

A magnitude ML 1.2 earthquake occured in region: 6 km S Montieri (GR), on

  • 18-09-2021 05:56:39 (UTC)
  • 18-09-2021 07:56:39 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.0780, 11.0200 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
Montieri GR 6 1204 1204
Chiusdino SI 10 1903 3107
Massa Marittima GR 11 8375 11482
Roccastrada GR 14 9199 20681
Monticiano SI 15 1571 22252
Monterotondo Marittimo GR 15 1371 23623
Castelnuovo di Val di Cecina PI 17 2231 25854
Gavorrano GR 19 8580 34434

Municipalities with at least 50000 inhabitants

An earthquake occurred to
36 Km N of Grosseto (82087 inhabitants)
37 Km SW of Siena (53903 inhabitants)
77 Km S of Scandicci (50609 inhabitants)
78 Km SE of Livorno (159219 inhabitants)
79 Km S of Firenze (382808 inhabitants)
82 Km SW of Arezzo (99543 inhabitants)
87 Km SE of Pisa (89158 inhabitants)
90 Km S of Prato (191150 inhabitants)
95 Km SE of Lucca (89046 inhabitants)
96 Km S of Pistoia (90315 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 		ML 1.2 2021-09-18
05:56:39		 43.0775 11.0198 10 2022-03-30
13:04:39		 Bollettino Sismico Italiano INGV 101586541
Reviewed
Rev100 		ML 1.2 2021-09-18
05:56:39		 43.0793 11.0237 10 2021-09-18
06:09:49		 Sala Sismica INGV-Roma 95574181
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-09-18 05:56:39 ± 0.21
Latitude 43.0775 ± 0.0108
Longitude 11.0198 ± 0.0172
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 101586541

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1261
Semi-minor axis of confidence ellipse (meter) 1111
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 82
Circular confidence region, given by single value of horizontal uncertainty (meter) 1260.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 134
Number of associated phases, regardless of their use for origin computation 33
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.39
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.30847
Number of stations at which the event was observed 29
Number of stations from which data was used for origin computation 4
Magnitudes information

ML:1.2

Field Value
Value 1.2
Uncertainty 0.3
Num. used stations 3
Type of magnitude ML
Reference to an origin 101586541
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2022-03-01 15:24:41

ML:1.2

Field Value
Value 1.2
Uncertainty 0.3
Num. used stations 3
Type of magnitude ML
Reference to an origin 95574181
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-09-18 06:09:49
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.PLAC.HHZ. 2021-09-18T05:58:07.44 3.0 undecidable manual Pn -1.95 0
IV.ESCV.HHZ. 2021-09-18T05:58:05.04 3.0 negative manual Pn -0.56 0
IV.TDS.HHZ. 2021-09-18T05:57:59.03 3.0 undecidable manual Pn 1.73 0
IV.FDMO.HHZ. 2021-09-18T05:57:58.85 3.0 undecidable manual Sg 13.3 0
IV.MCRV.HHZ. 2021-09-18T05:57:54.39 3.0 positive manual Pg 16.299999 0
IV.TERO.HHZ. 2021-09-18T05:57:54.61 3.0 undecidable manual Sn -3.09 0
IV.CDRU.HHZ. 2021-09-18T05:57:52.80 3.0 positive manual Pg 11.16 0
IV.OFFI.HHZ. 2021-09-18T05:57:52.75 3.0 undecidable manual Sn -3.8 0
IV.SAP2.EHZ. 2021-09-18T05:57:51.82 3.0 undecidable manual Sn 1.32 0
IV.CMPR.HHZ. 2021-09-18T05:57:49.99 3.0 undecidable manual Pn 6.91 0
IV.GAVE.EHZ. 2021-09-18T05:57:48.00 3.0 undecidable manual Sn 2.77 0
IV.ARRO.EHZ. 2021-09-18T05:57:45.43 3.0 undecidable manual Sn 1.15 0
IV.CRTC.HHZ. 2021-09-18T05:57:37.81 3.0 undecidable manual Sn -0.76 0
IV.RSM2.HHZ. 2021-09-18T05:57:34.03 3.0 undecidable manual Sn 3.4 0
IV.TST02.HHZ. 2021-09-18T05:57:29.55 3.0 undecidable manual Pg 7.04 0
IV.SGG.HHZ. 2021-09-18T05:57:28.60 3.0 positive manual Pn 1.98 0
IV.ZEN8.EHZ. 2021-09-18T05:57:18.06 3.0 undecidable manual Sn -1.89 0
IV.MMUR.HNZ. 2021-09-18T05:57:13.01 3.0 undecidable manual Pg 10.42 0
IV.TOLF.HHZ. 2021-09-18T05:57:07.19 3.0 undecidable manual Pg 5.86 0
IV.ZCCA.HNZ. 2021-09-18T05:57:07.00 3.0 undecidable manual Sg 1.02 0
IV.BARO.EHZ. 2021-09-18T05:57:03.30 3.0 undecidable manual Pg 3.1 0
IV.APEC.HHZ. 2021-09-18T05:56:58.14 3.0 negative manual Pg 1.51 0
IV.BRSN.HNZ. 2021-09-18T05:56:51.16 3.0 positive manual Pn -1.93 0
IV.LMD.HHZ. 2021-09-18T05:56:51.06 3.0 undecidable manual P 1.91 0
IV.CASP.HHZ. 2021-09-18T05:56:50.68 0.3 undecidable manual S 202 34.2435 50 -0.5 68
IV.FROS.CHZ. 2021-09-18T05:56:46.11 0.6 undecidable manual S 37 18.3705 119 -0.52 46
IV.CASP.HHZ. 2021-09-18T05:56:46.61 0.3 undecidable manual P 202 34.2435 50 0.42 69
IV.RIBO.EHZ.01 2021-09-18T05:56:45.24 0.6 undecidable manual S 171 14.3745 125 -0.23 49
IV.TRIF.CHZ. 2021-09-18T05:56:44.10 0.3 undecidable manual S 294 10.3785 134 -0.28 74
IV.RIBO.EHZ.01 2021-09-18T05:56:43.16 0.3 undecidable manual P 171 14.3745 125 0.27 74
IV.FROS.CHZ. 2021-09-18T05:56:43.71 0.1 undecidable manual P 37 18.3705 119 0.15 100
IV.TRIF.CHZ. 2021-09-18T05:56:42.54 0.1 negative manual P 294 10.3785 134 0.28 99
GU.GORR.HHZ. 2021-09-18T05:56:41.83 3.0 undecidable manual S -0.21 0
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.TRIF.CHE. ML:1.6 0.0005008484 0.2336 AML other m 2021-09-18T05:56:24.24
IV.TRIF.CHN. ML:1.0 0.00010867095 0.096 AML other m 2021-09-18T05:56:44.14
IV.RIBO.EHE.01 ML:1.1 0.00011588267499999999 0.16 AML other m 2021-09-18T05:56:45.41
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