Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.4 on date 19-12-2023 and time 13:59:44 (Italy) in region 5 km NW Seggiano (GR)

A magnitude ML 1.4 earthquake occured in region: 5 km NW Seggiano (GR), on

  • 19-12-2023 12:59:44 (UTC)
  • 19-12-2023 13:59:44 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.9680, 11.5270 at 8 km depth.

The earthquake was located by: Sala Sismica INGV-Roma.

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
Seggiano GR 5 961 961
Castel del Piano GR 8 4690 5651
Castiglione d'Orcia SI 9 2346 7997
Arcidosso GR 11 4285 12282
Montalcino SI 11 5093 17375
San Quirico d'Orcia SI 12 2662 20037
Cinigiano GR 14 2618 22655
Abbadia San Salvatore SI 16 6444 29099
Santa Fiora GR 16 2622 31721
Pienza SI 18 2107 33828
Piancastagnaio SI 19 4230 38058
Buonconvento SI 19 3173 41231

Municipalities with at least 50000 inhabitants

An earthquake occurred to
41 Km NE of Grosseto (82087 inhabitants)
42 Km SE of Siena (53903 inhabitants)
63 Km SW of Arezzo (99543 inhabitants)
72 Km W of Perugia (166134 inhabitants)
77 Km NW of Viterbo (67173 inhabitants)
92 Km S of Firenze (382808 inhabitants)
92 Km SE of Scandicci (50609 inhabitants)
96 Km W of Foligno (57155 inhabitants)
100 Km N of Civitavecchia (52991 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
Reviewed
Rev100 		ML 1.4 2023-12-19
12:59:44		 42.9678 11.527 8 2023-12-19
13:09:17		 Sala Sismica INGV-Roma 124143831
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-12-19 12:59:44 ± 0.15
Latitude 42.9678 ± 0.0117
Longitude 11.5270 ± 0.0074
Depth (km) 8 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 124143831

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1245
Semi-minor axis of confidence ellipse (meter) 609
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 189
Circular confidence region, given by single value of horizontal uncertainty (meter) 1240.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 114
Number of associated phases, regardless of their use for origin computation 14
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.28
Epicentral distance of station closest to the epicenter (degree) 0.12231
Epicentral distance of station farthest from the epicenter (degree) 0.48294
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitude information

ML:1.4

Field Value
Value 1.4
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 124143831
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-12-19 13:09:17
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MGAB.HHZ. 2023-12-19T13:00:00.79 0.3 undecidable manual S 97 47.9187 50 -0.14 70
IV.FROS.CHE. 2023-12-19T12:59:58.35 0.3 undecidable manual S 312 40.2264 50 -0.54 65
IV.SACS.HHZ. 2023-12-19T12:59:56.84 0.3 undecidable manual S 113 33.744 103 -0.14 72
IV.CAFI.HHZ. 2023-12-19T12:59:55.00 0.3 undecidable manual P 41 53.6019 50 -0.05 70
IV.LATE.HHZ. 2023-12-19T12:59:54.22 0.3 undecidable manual P 150 45.3213 50 0.45 66
IV.MGAB.HHZ. 2023-12-19T12:59:54.28 0.6 positive manual P 97 47.9187 50 0.11 47
IV.FROS.CHE. 2023-12-19T12:59:53.19 0.1 undecidable manual P 312 40.2264 50 0.19 93
IV.MCIV.CHZ. 2023-12-19T12:59:52.94 0.6 undecidable manual S 150 24.2535 108 -0.85 39
IV.SACS.HHZ. 2023-12-19T12:59:52.20 0.3 undecidable manual P 113 33.744 103 0.31 69
TV.SF11.HHZ. 2023-12-19T12:59:51.03 0.6 undecidable manual S 132 16.5723 115 -0.26 48
IV.MCIV.CHZ. 2023-12-19T12:59:50.18 0.1 negative manual P 150 24.2535 108 0.13 97
IV.ARCI.HHZ. 2023-12-19T12:59:50.28 0.1 undecidable manual S 198 13.5753 120 -0.08 100
TV.SF11.HHZ. 2023-12-19T12:59:48.83 0.6 positive manual P 132 16.5723 115 0.22 48
IV.ARCI.HHZ. 2023-12-19T12:59:48.22 0.1 positive manual P 198 13.5753 120 0.14 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ARCI.HHE. ML:1.6 0.0005015 0.22 AML other m 2023-12-19T12:59:51.17
TV.SF11.HHE. ML:1.6 0.00035450000000000005 1.1 AML other m 2023-12-19T12:59:52.71
IV.MCIV.CHE. ML:1.4 0.0001695 0.68 AML other m 2023-12-19T12:59:53.38
IV.ARCI.HHN. ML:1.5 0.0003465 0.62 AML other m 2023-12-19T12:59:53.78
IV.MCIV.CHN. ML:1.5 0.0002075 0.12 AML other m 2023-12-19T12:59:53.92
TV.SF11.HHN. ML:1.5 0.000315 0.42 AML other m 2023-12-19T12:59:54.09
IV.SACS.HHE. ML:0.9 0.000036400000000000004 0.54 AML other m 2023-12-19T12:59:59.70
IV.SACS.HHN. ML:0.8 0.000029350000000000002 1.36 AML other m 2023-12-19T13:00:02.07
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