Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.6 on date 28-10-2020 and time 06:12:24 (Italy) in region 2 km W Castiglione d'Orcia (SI)

A magnitude ML 1.6 earthquake occured in region: 2 km W Castiglione d'Orcia (SI), on

  • 28-10-2020 05:12:24 (UTC)
  • 28-10-2020 06:12:24 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.0090, 11.5940 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
Castiglione d'Orcia SI 2 2346 2346
San Quirico d'Orcia SI 6 2662 5008
Seggiano GR 9 961 5969
Montalcino SI 10 5093 11062
Pienza SI 10 2107 13169
Castel del Piano GR 14 4690 17859
Abbadia San Salvatore SI 16 6444 24303
Arcidosso GR 16 4285 28588
San Giovanni d'Asso SI 16 853 29441
Buonconvento SI 17 3173 32614
Montepulciano SI 18 14097 46711
Radicofani SI 19 1097 47808
Piancastagnaio SI 19 4230 52038
Santa Fiora GR 20 2622 54660

Municipalities with at least 50000 inhabitants

An earthquake occurred to
41 Km SE of Siena (53903 inhabitants)
48 Km NE of Grosseto (82087 inhabitants)
56 Km SW of Arezzo (99543 inhabitants)
66 Km W of Perugia (166134 inhabitants)
78 Km NW of Viterbo (67173 inhabitants)
89 Km SE of Firenze (382808 inhabitants)
90 Km SE of Scandicci (50609 inhabitants)
91 Km W of Foligno (57155 inhabitants)
99 Km NW of Terni (111501 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 2020-10-28
05:12:24		 43.0087 11.5942 10 2021-02-26
14:56:02		 Bollettino Sismico Italiano INGV 84441771
Reviewed
Rev100 		ML 1.6 2020-10-28
05:12:24		 43.0142 11.6023 10 2020-10-28
06:03:13		 Sala Sismica INGV-Roma 84201991
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-10-28 05:12:24 ± 0.1
Latitude 43.0087 ± 0.0045
Longitude 11.5942 ± 0.0074
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 84441771

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 562
Semi-minor axis of confidence ellipse (meter) 481
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 229
Circular confidence region, given by single value of horizontal uncertainty (meter) 560.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 65
Number of associated phases, regardless of their use for origin computation 27
Number of defining phases 25
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.26
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.51441
Number of stations at which the event was observed 16
Number of stations from which data was used for origin computation 14
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 12
Type of magnitude ML
Reference to an origin 84201991
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-10-28 06:03:13

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 12
Type of magnitude ML
Reference to an origin 84441771
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-01-11 15:17:32
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.PII.HHZ. 2020-10-28T05:12:54.29 3.0 undecidable manual S -1.29 0
IV.MNTT.EHZ. 2020-10-28T05:12:50.93 3.0 negative manual Pn 0.02 0
IV.CAFI.HHZ. 2020-10-28T05:12:39.02 0.6 undecidable manual S 40 46.62 50 -0.21 46
IV.MGAB.HHZ. 2020-10-28T05:12:38.71 0.3 undecidable manual S 104 43.4232 50 0.34 67
IV.FROS.CHZ. 2020-10-28T05:12:37.69 0.6 undecidable manual S 302 41.9247 50 -0.28 46
IV.SACS.HHZ. 2020-10-28T05:12:34.70 0.6 undecidable manual S 125 31.1466 50 -0.41 45
IV.CSNT.HHE. 2020-10-28T05:12:34.03 0.1 undecidable manual P 335 57.0984 50 -0.44 85
IV.MCIV.CHZ. 2020-10-28T05:12:33.34 0.3 undecidable manual S 165 26.3514 50 -0.49 68
IV.RIBO.EHZ.01 2020-10-28T05:12:32.90 0.1 undecidable manual P 262 44.9217 50 0.3 90
TV.SF03.EHZ. 2020-10-28T05:12:32.63 0.6 undecidable manual S 162 24.0537 50 -0.57 44
IV.FROS.CHZ. 2020-10-28T05:12:32.08 0.3 undecidable manual P 302 41.9247 50 -0.05 72
TV.SF01.EHZ. 2020-10-28T05:12:32.88 0.1 undecidable manual S 187 21.9669 115 0.32 94
IV.MGAB.HHZ. 2020-10-28T05:12:32.51 0.1 undecidable manual P 104 43.4232 50 0.15 93
IV.CAFI.HHZ. 2020-10-28T05:12:32.75 0.1 undecidable manual P 40 46.62 50 -0.1 93
IV.ARCI.HHZ. 2020-10-28T05:12:31.98 0.6 undecidable manual S 209 19.869 117 0.07 50
TV.SF13.HHE. 2020-10-28T05:12:31.90 0.3 undecidable manual S 174 21.1677 116 -0.42 68
TV.SF04.EHZ. 2020-10-28T05:12:31.52 0.3 undecidable manual S 164 19.9689 117 -0.41 68
IV.SACS.HHZ. 2020-10-28T05:12:30.95 0.3 undecidable manual P 125 31.1466 50 0.47 66
TV.SF14.HHN. 2020-10-28T05:12:30.18 0.1 undecidable manual P 177 28.1496 50 0.16 95
TV.SF11.HHE. 2020-10-28T05:12:30.72 0.6 undecidable manual S 156 16.9719 121 -0.31 47
TV.SF03.EHZ. 2020-10-28T05:12:29.45 0.1 undecidable manual P 162 24.0537 50 0.07 97
TV.SF13.HHE. 2020-10-28T05:12:29.11 0.1 undecidable manual P 174 21.1677 116 0.24 96
IV.MCIV.CHZ. 2020-10-28T05:12:29.89 0.1 undecidable manual P 165 26.3514 50 0.15 95
TV.SF01.EHZ. 2020-10-28T05:12:29.06 0.1 undecidable manual P 187 21.9669 115 0.05 99
TV.SF04.EHZ. 2020-10-28T05:12:28.86 0.1 undecidable manual P 164 19.9689 117 0.22 96
TV.SF11.HHE. 2020-10-28T05:12:28.30 0.1 undecidable manual P 156 16.9719 121 0.18 98
IV.ARCI.HHZ. 2020-10-28T05:12:28.66 0.1 undecidable manual P 209 19.869 117 0.03 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF04.EHE. ML:2.3 0.0014900000000000002 0.24 AML other m 2020-10-28T05:12:32.63
TV.SF01.EHE. ML:1.9 0.000557 0.24 AML other m 2020-10-28T05:12:33.19
TV.SF01.EHN. ML:2.2 0.00118 0.24 AML other m 2020-10-28T05:12:33.18
TV.SF04.EHN. ML:2.1 0.0009764999999999999 0.3 AML other m 2020-10-28T05:12:34.53
IV.ARCI.HHN. ML:1.5 0.00023349999999999998 0.42 AML other m 2020-10-28T05:12:34.61
IV.MCIV.CHE. ML:1.6 0.00020700000000000002 0.26 AML other m 2020-10-28T05:12:35.04
IV.ARCI.HHE. ML:1.5 0.000248 0.58 AML other m 2020-10-28T05:12:35.35
IV.MCIV.CHN. ML:1.6 0.00023199999999999997 0.62 AML other m 2020-10-28T05:12:36.77
IV.FROS.CHE. ML:1.5 0.00010089999999999999 1.42 AML other m 2020-10-28T05:12:39.88
IV.CAFI.HHN. ML:1.4 0.00007165 0.94 AML other m 2020-10-28T05:12:39.78
IV.FROS.CHN. ML:1.5 0.0000949 0.38 AML other m 2020-10-28T05:12:40.75
IV.CAFI.HHE. ML:1.2 0.000045600000000000004 0.48 AML other m 2020-10-28T05:12:41.54
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