Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.6 on date 04-12-2021 and time 15:46:27 (UTC) in region 5 km NW Chiusdino (SI)

A magnitude ML 1.6 earthquake occured in region: 5 km NW Chiusdino (SI), on

  • 04-12-2021 15:46:27 (UTC)
  • 04-12-2021 16:46:27 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.1930, 11.0510 at 9 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
Chiusdino SI 5 1903 1903
Montieri GR 7 1204 3107
Radicondoli SI 8 914 4021
Castelnuovo di Val di Cecina PI 12 2231 6252
Monticiano SI 12 1571 7823
Monterotondo Marittimo GR 17 1371 9194
Casole d'Elsa SI 17 3897 13091
Sovicille SI 18 10116 23207
Pomarance PI 19 5897 29104

Municipalities with at least 50000 inhabitants

An earthquake occurred to
27 Km SW of Siena (53903 inhabitants)
48 Km N of Grosseto (82087 inhabitants)
64 Km S of Scandicci (50609 inhabitants)
66 Km S of Firenze (382808 inhabitants)
72 Km SE of Livorno (159219 inhabitants)
74 Km W of Arezzo (99543 inhabitants)
77 Km S of Prato (191150 inhabitants)
78 Km SE of Pisa (89158 inhabitants)
83 Km S of Pistoia (90315 inhabitants)
85 Km SE of Lucca (89046 inhabitants)
99 Km SE of Viareggio (62467 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 1.6 2021-12-04
15:46:27		 43.1927 11.0508 9 2022-03-30
13:04:35		 Bollettino Sismico Italiano INGV 100568761
Reviewed
Rev100 		ML 1.6 2021-12-04
15:46:27		 43.1953 11.0497 9 2021-12-04
15:56:55		 Sala Sismica INGV-Roma 98135851
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-12-04 15:46:27 ± 0.17
Latitude 43.1927 ± 0.0126
Longitude 11.0508 ± 0.0197
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 100568761

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1864
Semi-minor axis of confidence ellipse (meter) 498
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 129
Circular confidence region, given by single value of horizontal uncertainty (meter) 1860.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 104
Number of associated phases, regardless of their use for origin computation 35
Number of defining phases 13
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.46
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.75903
Number of stations at which the event was observed 27
Number of stations from which data was used for origin computation 8
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 6
Type of magnitude ML
Reference to an origin 98135851
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-12-04 15:56:55

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 6
Type of magnitude ML
Reference to an origin 100568761
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2022-02-03 15:45:12
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MCRV.HHZ. 2021-12-04T15:48:08.64 3.0 undecidable manual Sn -0.77 0
IV.MTMR.HNZ. 2021-12-04T15:48:05.38 3.0 undecidable manual Sn 0.49 0
IV.GIZZ.HHZ. 2021-12-04T15:48:02.63 3.0 undecidable manual Pg 15.47 0
OT.OT13.EHZ. 2021-12-04T15:48:02.38 3.0 undecidable manual Sn -4.61 0
IV.POFI.HHZ. 2021-12-04T15:47:42.78 3.0 undecidable manual Sg 8.2 0
IV.TDS.HHZ. 2021-12-04T15:47:42.38 3.0 undecidable manual Pn 1.72 0
OT.OT13.EHZ. 2021-12-04T15:47:36.63 3.0 negative manual Pg 17.030001 0
IV.MCRV.HHZ. 2021-12-04T15:47:35.06 3.0 undecidable manual Pg 14.1 0
IV.MTMR.HNZ. 2021-12-04T15:47:25.06 3.0 undecidable manual Pg 6.64 0
IV.FAGN.HHZ. 2021-12-04T15:47:21.36 3.0 undecidable manual Sn -1.77 0
IV.EL6.EHZ. 2021-12-04T15:47:03.46 3.0 undecidable manual Sn 1.97 0
IV.CSP1.EHZ. 2021-12-04T15:47:00.66 3.0 undecidable manual Sn -4.92 0
IV.ARVD.HHZ. 2021-12-04T15:46:59.92 3.0 undecidable manual Sg 2.42 0
IT.CSO1.HGZ. 2021-12-04T15:46:58.90 3.0 positive manual Pg 5.58 0
IV.TERO.HHZ. 2021-12-04T15:46:55.56 3.0 undecidable manual Pg 3.6 0
IV.RCAV.EHZ. 2021-12-04T15:46:53.36 3.0 positive manual Pn -2.05 0
IV.NARO.HHZ. 2021-12-04T15:46:50.21 3.0 undecidable manual Sn -0.4 0
IV.PIEI.HHZ. 2021-12-04T15:46:47.02 3.0 undecidable manual Sn -3.29 0
IV.MC2.EHZ. 2021-12-04T15:46:47.54 3.0 undecidable manual Pn 1.29 0
IV.MMUR.HNZ. 2021-12-04T15:46:47.07 3.0 negative manual Pg 5.76 0
IV.CELB.HHZ. 2021-12-04T15:46:43.22 0.3 undecidable manual P 234 84.249 50 1.11 46
IV.CASP.HHZ. 2021-12-04T15:46:42.42 0.3 undecidable manual S 199 47.0196 50 -0.51 64
IV.CSNT.HHE. 2021-12-04T15:46:39.50 0.3 undecidable manual S 32 36.6411 50 -0.65 62
IV.CASP.HHZ. 2021-12-04T15:46:37.00 0.3 undecidable manual P 199 47.0196 50 0.62 61
IV.OSSC.HHE. 2021-12-04T15:46:36.08 0.3 undecidable manual P 23 39.9267 50 0.8 58
IV.RIBO.EHZ.01 2021-12-04T15:46:36.84 0.6 undecidable manual S 181 27.0507 108 -0.46 45
IV.CSNT.HHE. 2021-12-04T15:46:34.57 0.3 undecidable manual P 32 36.6411 50 -0.2 70
IV.CPGN.EHZ. 2021-12-04T15:46:33.30 3.0 undecidable manual P 0.12 0
IV.TRIF.CHZ. 2021-12-04T15:46:33.01 0.6 undecidable manual S 234 14.7741 121 -0.39 46
IV.MAGO.CHE. 2021-12-04T15:46:33.76 0.3 undecidable manual P 286 32.9448 50 -0.45 66
IV.RIBO.EHZ.01 2021-12-04T15:46:33.32 0.3 undecidable manual P 181 27.0507 108 0.19 71
IV.FROS.CHZ. 2021-12-04T15:46:31.57 0.6 undecidable manual S 77 8.7801 135 -0.17 49
IV.TRIF.CHZ. 2021-12-04T15:46:30.86 0.1 undecidable manual P 234 14.7741 121 -0.02 100
IV.FROS.CHZ. 2021-12-04T15:46:30.09 0.1 positive manual P 77 8.7801 135 0.17 98
IV.ZCCA.HHZ. 2021-12-04T15:46:30.18 3.0 undecidable manual P -1.08 0
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.FROS.CHN. ML:1.6 0.0006365 0.52 AML other m 2021-12-04T15:46:31.95
IV.TRIF.CHE. ML:2.0 0.00107 0.24 AML other m 2021-12-04T15:46:33.68
IV.TRIF.CHN. ML:1.9 0.0008575 1.14 AML other m 2021-12-04T15:46:33.78
IV.FROS.CHE. ML:1.5 0.0005055000000000001 1.2 AML other m 2021-12-04T15:46:33.99
IV.RIBO.EHN.01 ML:1.4 0.00012302265 0.6016 AML other m 2021-12-04T15:46:37.26
IV.RIBO.EHE.01 ML:1.1 0.000073528015 0.1024 AML other m 2021-12-04T15:46:38.41
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