Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.8 on date 18-09-2021 and time 08:04:07 (Italy) in region 6 km S Montieri (GR)

A magnitude ML 0.8 earthquake occured in region: 6 km S Montieri (GR), on

  • 18-09-2021 06:04:07 (UTC)
  • 18-09-2021 08:04:07 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.0790, 11.0180 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 0.8 2021-09-18
06:04:07		 43.0788 11.0175 10 2022-03-30
13:04:39		 Bollettino Sismico Italiano INGV 101586631
Reviewed
Rev100 		ML 0.8 2021-09-18
06:04:07		 43.0798 11.0063 12 2021-09-18
06:13:50		 Sala Sismica INGV-Roma 95574341
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-09-18 06:04:07 ± 0.19
Latitude 43.0788 ± 0.0090
Longitude 11.0175 ± 0.0160
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 101586631

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1119
Semi-minor axis of confidence ellipse (meter) 1052
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 312
Circular confidence region, given by single value of horizontal uncertainty (meter) 1120.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 133
Number of associated phases, regardless of their use for origin computation 30
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.33
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 25
Number of stations from which data was used for origin computation 4
Magnitudes information

ML:0.8

Field Value
Value 0.8
Uncertainty 0.2
Num. used stations 5
Type of magnitude ML
Reference to an origin 101586631
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2022-03-01 15:28:08

ML:0.8

Field Value
Value 0.8
Uncertainty 0.2
Num. used stations 5
Type of magnitude ML
Reference to an origin 95574341
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-09-18 06:13:50
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CDRU.HHZ. 2021-09-18T06:05:54.25 3.0 undecidable manual Sn -5.82 0
IV.PLAC.HHZ. 2021-09-18T06:05:50.14 3.0 negative manual Pg 11.35 0
IV.TDS.HHZ. 2021-09-18T06:05:34.61 3.0 negative manual Pg 8.69 0
IX.PGN3.HHZ.02 2021-09-18T06:05:27.61 3.0 undecidable manual Pg 14.15 0
IX.STN3.HNZ.01 2021-09-18T06:05:23.92 3.0 undecidable manual Pg 11.29 0
IV.POFI.HHZ. 2021-09-18T06:05:21.59 3.0 undecidable manual Sg 3.29 0
IV.EUCT.HNZ. 2021-09-18T06:05:12.83 3.0 undecidable manual Sn -3.81 0
SL.LJU.BHZ. 2021-09-18T06:05:11.12 3.0 undecidable manual Pg 6.18 0
IV.FAGN.HHZ. 2021-09-18T06:05:08.97 3.0 undecidable manual Sn -0.27 0
IV.SARZ.HHZ. 2021-09-18T06:05:03.30 3.0 undecidable manual Sn -9.26 0
MN.TRI.HHZ. 2021-09-18T06:04:58.67 3.0 undecidable manual Pn 2 0
IV.BAG8.EHZ. 2021-09-18T06:04:57.33 3.0 undecidable manual Pg 8.17 0
IV.VENT.EHZ. 2021-09-18T06:04:55.02 3.0 undecidable manual Pn 1.35 0
GU.CANO.HHZ. 2021-09-18T06:04:51.04 3.0 undecidable manual Pg 7.66 0
IV.ZEN8.EHZ. 2021-09-18T06:04:49.73 3.0 undecidable manual Pg 3.37 0
IV.ZCCA.HNZ. 2021-09-18T06:04:46.76 3.0 undecidable manual Sg 0.73 0
IV.RMP.HHZ. 2021-09-18T06:04:36.50 3.0 negative manual Pn -1.67 0
IV.GAVE.EHZ. 2021-09-18T06:04:32.48 3.0 negative manual Pg -0.4 0
IV.APEC.HHZ. 2021-09-18T06:04:25.64 3.0 negative manual P -2.13 0
IV.ZCCA.HNZ. 2021-09-18T06:04:25.64 3.0 undecidable manual Pn -2.96 0
IV.FIR.HHZ. 2021-09-18T06:04:20.69 3.0 undecidable manual P 1.61 0
IV.CASP.HHZ. 2021-09-18T06:04:19.01 0.6 undecidable manual S 201 34.2435 50 -0.5 45
IT.FIE.HGZ. 2021-09-18T06:04:18.13 3.0 undecidable manual P -1.69 0
IV.CASP.HHZ. 2021-09-18T06:04:14.73 0.3 undecidable manual P 201 34.2435 50 0.21 73
IV.FROS.CHZ. 2021-09-18T06:04:14.45 0.6 undecidable manual S 38 18.3705 119 -0.51 47
IV.RIBO.EHZ.01 2021-09-18T06:04:13.67 0.6 undecidable manual S 171 14.5743 125 -0.19 50
IV.FROS.CHZ. 2021-09-18T06:04:12.09 0.1 undecidable manual P 38 18.3705 119 0.2 100
IV.TRIF.CHZ. 2021-09-18T06:04:12.33 0.6 undecidable manual S 293 10.0788 135 -0.33 49
IV.RIBO.EHZ.01 2021-09-18T06:04:11.48 0.3 undecidable manual P 171 14.5743 125 0.23 75
IV.TRIF.CHZ. 2021-09-18T06:04:10.84 0.3 undecidable manual P 293 10.0788 135 0.28 75
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.TRIF.CHE. ML:0.8 0.00007472029499999999 0.0736 AML other m 2021-09-18T06:04:12.43
IV.TRIF.CHN. ML:0.6 0.00005242806 0.096 AML other m 2021-09-18T06:04:12.49
IV.RIBO.EHE.01 ML:0.6 0.00004055410489 0.1408 AML other m 2021-09-18T06:04:14.11
IV.FROS.CHN. ML:1.0 0.00008564146000000001 0.2176 AML other m 2021-09-18T06:04:14.80
IV.CASP.HHN. ML:0.9 0.000027526639999999998 0.1408 AML other m 2021-09-18T06:04:19.15
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