Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.3 on date 23-12-2020 and time 03:14:55 (Italy) in region 2 km S Pomarance (PI)

A magnitude ML 1.3 earthquake occured in region: 2 km S Pomarance (PI), on

  • 23-12-2020 02:14:55 (UTC)
  • 23-12-2020 03:14:55 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.28, 10.87 at 9 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
Pomarance PI 2 5897 5897
Castelnuovo di Val di Cecina PI 9 2231 8128
Volterra PI 14 10519 18647
Radicondoli SI 14 914 19561
Monterotondo Marittimo GR 15 1371 20932
Casole d'Elsa SI 16 3897 24829
Montecatini Val di Cecina PI 16 1749 26578
Monteverdi Marittimo PI 17 758 27336
Guardistallo PI 20 1234 28570

Municipalities with at least 50000 inhabitants

An earthquake occurred to
38 Km W of Siena (53903 inhabitants)
55 Km SE of Livorno (159219 inhabitants)
59 Km SW of Scandicci (50609 inhabitants)
61 Km NW of Grosseto (82087 inhabitants)
61 Km SE of Pisa (89158 inhabitants)
63 Km SW of Firenze (382808 inhabitants)
69 Km S of Prato (191150 inhabitants)
69 Km SE of Lucca (89046 inhabitants)
73 Km S of Pistoia (90315 inhabitants)
82 Km SE of Viareggio (62467 inhabitants)
84 Km W of Arezzo (99543 inhabitants)
Recent and historical Seismicity
Seismic hazard
Shakemap
Felt maps
The earthquake effects in MCS scale as obtained from the compiled questionnaire

The earthquake effects in MCS scale as obtained from the compiled questionnaire

This map shows the distribution of the effects of the earthquake on the territory in terms of the MCS (Mercalli-Cancani-Sieberg) intensity scale. The intensities are determined using the data provided in the questionnaire (http://www.haisentitoilterremoto.it/) that are analysed using robust statistical techniques since they are not verified individually. Specifically, the assignment of MCS intensities greater or equal the VI degree of the MCS scale require opportune in situ verification by professional experts. The purple start shows the epicenter. This map is prepared every so often that the population fill in new questionnaires. The number of questionnaires used to determine the map and the date and time of the last adjournment are shown in the upper right part of the panel.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Reviewed
Rev100 		ML 1.3 2020-12-23
02:14:55		 43.28 10.87 9 2020-12-23
02:21:53		 Sala Sismica INGV-Roma 85641421
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-12-23 02:14:55 ± 0.16
Latitude 43.28 ± 0.01
Longitude 10.87 ± 0.01
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 85641421

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 761
Semi-minor axis of confidence ellipse (meter) 560
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 120
Circular confidence region, given by single value of horizontal uncertainty (meter) 760
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 108
Number of associated phases, regardless of their use for origin computation 21
Number of defining phases 18
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.29
Epicentral distance of station closest to the epicenter (degree) 0
Epicentral distance of station farthest from the epicenter (degree) 0.76712
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 9
Magnitude information

ML:1.3

Field Value
Value 1.3
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 85641421
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-12-23 02:21:53
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.MAGA.HHZ. 2020-12-23T02:15:35.50 3.0 undecidable manual Pn -0.63 0
IV.TOLF.HHZ. 2020-12-23T02:15:22.88 3.0 negative manual P -0.27 0
GU.POPM.HHZ. 2020-12-23T02:15:21.70 0.6 undecidable manual S 354 0.7671 50 0.34 43
IV.CELB.HHZ. 2020-12-23T02:15:20.11 0.6 undecidable manual S 222 0.7204 50 0.14 45
IV.RUFI.EHZ. 2020-12-23T02:15:19.98 0.3 undecidable manual S 39 0.7231 50 -0.05 69
IV.MAON.HHZ. 2020-12-23T02:15:14.08 3.0 negative manual P 0.17 0
IV.CASP.HHZ. 2020-12-23T02:15:13.07 0.6 undecidable manual S 181 0.4901 50 -0.08 48
IV.PII.HHZ. 2020-12-23T02:15:12.76 0.6 undecidable manual S 330 0.5072 50 -0.87 38
GU.POPM.HHZ. 2020-12-23T02:15:11.11 0.6 negative manual P 354 0.7671 50 0.57 40
IV.RUFI.EHZ. 2020-12-23T02:15:10.37 0.6 undecidable manual P 39 0.7231 50 0.59 40
IV.CELB.HHZ. 2020-12-23T02:15:09.98 0.6 undecidable manual P 222 0.7204 50 0.24 44
IV.CSNT.HHZ. 2020-12-23T02:15:08.90 0.3 undecidable manual S 58 0.3588 50 -0.36 70
IV.RIBO.EHZ.01 2020-12-23T02:15:08.95 0.3 undecidable manual S 159 0.3561 50 -0.21 72
IV.CASP.HHZ. 2020-12-23T02:15:06.22 0.6 undecidable manual P 181 0.4901 50 0.41 45
IV.PII.HHZ. 2020-12-23T02:15:05.50 0.6 positive manual P 330 0.5072 50 -0.58 42
IV.FROS.CHZ. 2020-12-23T02:15:04.77 0.3 undecidable manual S 109 0.2194 111 -0.05 76
IV.RIBO.EHZ.01 2020-12-23T02:15:03.97 0.6 undecidable manual P 159 0.3561 50 0.47 45
IV.CSNT.HHZ. 2020-12-23T02:15:03.56 0.1 positive manual P 58 0.3588 50 0 100
IV.TRIF.CHZ. 2020-12-23T02:15:02.55 0.3 undecidable manual S 172 0.1682 117 -0.47 71
IV.FROS.CHZ. 2020-12-23T02:15:01.19 0.1 negative manual P 109 0.2194 111 0.19 99
IV.TRIF.CHZ. 2020-12-23T02:15:00.01 0.3 undecidable manual P 172 0.1682 117 0.05 77
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.TRIF.CHE. ML:1.7 0.000379 0.48 AML other m 2020-12-23T02:15:03.28
IV.TRIF.CHN. ML:1.5 0.000248 0.96 AML other m 2020-12-23T02:15:03.86
IV.FROS.CHN. ML:1.3 0.00012005 0.42 AML other m 2020-12-23T02:15:04.58
IV.FROS.CHE. ML:1.2 0.00010195 0.18 AML other m 2020-12-23T02:15:06.43
IV.CSNT.HHN. ML:1.1 4.7E-5 0.88 AML other m 2020-12-23T02:15:09.99
IV.CSNT.HHE. ML:0.9 3.095E-5 0.12 AML other m 2020-12-23T02:15:09.92
IV.CASP.HHE. ML:0.9 1.785E-5 1.08 AML other m 2020-12-23T02:15:17.74
IV.CASP.HHN. ML:0.9 1.78E-5 0.4 AML other m 2020-12-23T02:15:17.75
IV.CELB.HHN. ML:1.5 4.735E-5 1.08 AML other m 2020-12-23T02:15:20.45
IV.CELB.HHE. ML:1.8 8.65E-5 0.74 AML other m 2020-12-23T02:15:21.56
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download