Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.7 on date 28-10-2020 and time 03:45:58 (Italy) in region 2 km SW Castiglione d'Orcia (SI)

A magnitude ML 1.7 earthquake occured in region: 2 km SW Castiglione d'Orcia (SI), on

  • 28-10-2020 02:45:58 (UTC)
  • 28-10-2020 03:45:58 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.99, 11.6 at 11 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
Seggiano GR 7 961 3307
San Quirico d'Orcia SI 8 2662 5969
Castel del Piano GR 12 4690 10659
Pienza SI 12 2107 12766
Montalcino SI 12 5093 17859
Abbadia San Salvatore SI 13 6444 24303
Arcidosso GR 14 4285 28588
Radicofani SI 17 1097 29685
Piancastagnaio SI 17 4230 33915
Santa Fiora GR 17 2622 36537
San Giovanni d'Asso SI 18 853 37390
Montepulciano SI 19 14097 51487
Buonconvento SI 19 3173 54660
Cinigiano GR 20 2618 57278

Municipalities with at least 50000 inhabitants

An earthquake occurred to
43 Km SE of Siena (53903 inhabitants)
47 Km NE of Grosseto (82087 inhabitants)
58 Km SW of Arezzo (99543 inhabitants)
66 Km W of Perugia (166134 inhabitants)
76 Km NW of Viterbo (67173 inhabitants)
90 Km W of Foligno (57155 inhabitants)
91 Km SE of Firenze (382808 inhabitants)
92 Km SE of Scandicci (50609 inhabitants)
98 Km W 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 1.7 2020-10-28
02:45:58		 42.99 11.6 11 2021-02-26
14:56:02		 Bollettino Sismico Italiano INGV 84414621
Reviewed
Rev100 		ML 1.6 2020-10-28
02:45:58		 43.01 11.6 11 2020-10-28
02:55:54		 Sala Sismica INGV-Roma 84194591
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-10-28 02:45:58 ± 0.08
Latitude 42.99 ± 0.01
Longitude 11.60 ± 0.01
Depth (km) 11 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 84414621

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1030
Semi-minor axis of confidence ellipse (meter) 490
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 245
Circular confidence region, given by single value of horizontal uncertainty (meter) 1030
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 40
Number of associated phases, regardless of their use for origin computation 39
Number of defining phases 39
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.34
Epicentral distance of station closest to the epicenter (degree) 0.1322
Epicentral distance of station farthest from the epicenter (degree) 0.85166
Number of stations at which the event was observed 23
Number of stations from which data was used for origin computation 23
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.4
Num. used stations 20
Type of magnitude ML
Reference to an origin 84194591
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-10-28 02:55:54

ML:1.7

Field Value
Value 1.7
Uncertainty 0.4
Num. used stations 22
Type of magnitude ML
Reference to an origin 84414621
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-01-11 12:42:56
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.ATMI.HHZ. 2020-10-28T02:46:18.95 0.1 undecidable manual S 54 0.5971 90 0.24 86
IV.CASP.HHZ. 2020-10-28T02:46:18.65 0.1 undecidable manual S 250 0.5729 90 0.65 81
IV.CSNT.HHZ. 2020-10-28T02:46:15.91 0.1 undecidable manual S 335 0.5351 90 -0.95 70
IV.RUFI.EHN. 2020-10-28T02:46:14.47 0.1 undecidable manual P 356 0.8517 90 -0.08 86
IV.PARC.HHZ. 2020-10-28T02:46:13.70 0.1 undecidable manual P 35 0.8067 90 -0.08 88
IV.CAFI.HHZ. 2020-10-28T02:46:13.27 0.1 undecidable manual S 38 0.4326 90 -0.57 86
IV.RIBO.EHZ.01 2020-10-28T02:46:12.95 0.1 undecidable manual S 265 0.4065 90 -0.11 92
IV.SSP9.EHZ. 2020-10-28T02:46:12.35 0.1 undecidable manual P 33 0.7015 90 0.38 82
IV.MURB.HHZ. 2020-10-28T02:46:12.79 0.1 undecidable manual P 68 0.7285 90 0.36 82
IV.MGAB.HHZ. 2020-10-28T02:46:12.03 0.1 undecidable manual S 101 0.3822 90 -0.29 92
IV.ATVO.HHZ. 2020-10-28T02:46:12.31 0.1 undecidable manual P 56 0.7078 90 0.23 85
IV.MAON.HHZ. 2020-10-28T02:46:11.87 0.6 undecidable manual P 212 0.6574 90 0.65 39
IV.FROS.CHZ. 2020-10-28T02:46:11.86 0.6 undecidable manual S 305 0.3921 90 -0.78 38
IV.BADI.EHZ. 2020-10-28T02:46:11.84 0.1 undecidable manual P 42 0.7015 90 -0.13 89
IV.ATMI.HHZ. 2020-10-28T02:46:10.51 0.1 undecidable manual P 54 0.5971 90 0.32 85
IV.CASP.HHZ. 2020-10-28T02:46:10.45 0.1 undecidable manual P 250 0.5729 90 0.67 79
IV.SACS.HHZ. 2020-10-28T02:46:08.72 0.6 undecidable manual S 121 0.2653 90 -0.16 48
IV.CSNT.HHZ. 2020-10-28T02:46:08.19 0.3 undecidable manual P 335 0.5351 90 -0.93 53
IV.MCIV.CHZ. 2020-10-28T02:46:07.17 0.3 undecidable manual S 165 0.2167 90 -0.26 71
TV.SF14.HHN. 2020-10-28T02:46:07.62 0.3 undecidable manual S 177 0.2329 90 -0.29 70
IV.MGAB.HHZ. 2020-10-28T02:46:06.38 0.1 undecidable manual P 101 0.3822 90 -0.12 95
TV.SF01.EHZ. 2020-10-28T02:46:06.20 0.3 undecidable manual S 189 0.1781 90 -0.09 73
IV.CAFI.HHZ. 2020-10-28T02:46:06.81 0.1 undecidable manual P 38 0.4326 90 -0.57 85
IV.RIBO.EHZ.01 2020-10-28T02:46:06.98 0.1 positive manual P 265 0.4065 90 0.05 96
TV.SF03.EHN. 2020-10-28T02:46:06.62 0.1 undecidable manual S 161 0.1952 90 -0.18 97
IV.FROS.CHZ. 2020-10-28T02:46:06.17 0.1 undecidable manual P 305 0.3921 90 -0.52 85
TV.SF13.HHE. 2020-10-28T02:46:05.95 0.1 undecidable manual S 175 0.17 90 -0.1 98
TV.SF04.EHZ. 2020-10-28T02:46:05.59 0.3 undecidable manual S 164 0.1583 90 -0.12 74
IV.ARCI.HHZ. 2020-10-28T02:46:05.89 0.6 undecidable manual S 214 0.1637 90 0.03 50
TV.SF14.HHN. 2020-10-28T02:46:04.26 0.1 positive manual P 177 0.2329 90 0.3 93
TV.SF11.HHE. 2020-10-28T02:46:04.73 0.1 undecidable manual S 154 0.1322 90 -0.2 97
IV.SACS.HHZ. 2020-10-28T02:46:04.81 0.1 undecidable manual P 121 0.2653 90 0.29 92
IV.MCIV.CHZ. 2020-10-28T02:46:03.93 0.1 undecidable manual P 165 0.2167 90 0.25 94
TV.SF13.HHE. 2020-10-28T02:46:03.16 0.1 undecidable manual P 175 0.17 90 0.28 95
TV.SF03.EHN. 2020-10-28T02:46:03.60 0.1 undecidable manual P 161 0.1952 90 0.29 94
TV.SF01.EHZ. 2020-10-28T02:46:03.17 0.1 undecidable manual P 189 0.1781 90 0.15 97
TV.SF04.EHZ. 2020-10-28T02:46:02.90 0.1 undecidable manual P 164 0.1583 90 0.22 96
TV.SF11.HHE. 2020-10-28T02:46:02.39 0.1 undecidable manual P 154 0.1322 90 0.15 98
IV.ARCI.HHZ. 2020-10-28T02:46:02.79 0.1 positive manual P 214 0.1637 90 0.01 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF04.EHN. ML:2.5 0.00263 0.1 AML other m 2020-10-28T02:46:05.71
TV.SF04.EHE. ML:2.4 0.00202 0.24 AML other m 2020-10-28T02:46:06.81
IV.ARCI.HHN. ML:1.6 0.000309 1.04 AML other m 2020-10-28T02:46:07.61
TV.SF01.EHE. ML:2.2 0.001065 0.26 AML other m 2020-10-28T02:46:07.39
TV.SF01.EHN. ML:2.4 0.00203 0.22 AML other m 2020-10-28T02:46:07.25
IV.ARCI.HHE. ML:1.6 0.000317 0.7 AML other m 2020-10-28T02:46:08.54
IV.MCIV.CHE. ML:1.8 0.000352 0.26 AML other m 2020-10-28T02:46:09.53
IV.MCIV.CHN. ML:1.7 0.000301 0.42 AML other m 2020-10-28T02:46:10.25
IV.SACS.HHN. ML:1.2 6.775E-5 1.28 AML other m 2020-10-28T02:46:12.70
IV.SACS.HHE. ML:1.2 8.28E-5 0.54 AML other m 2020-10-28T02:46:12.41
IV.CAFI.HHN. ML:1.3 6.15E-5 0.56 AML other m 2020-10-28T02:46:14.55
IV.CAFI.HHE. ML:1.3 5.58E-5 0.28 AML other m 2020-10-28T02:46:14.77
IV.FROS.CHN. ML:1.6 0.00010795 0.84 AML other m 2020-10-28T02:46:16.04
IV.CSNT.HHE. ML:1.5 7.205E-5 0.88 AML other m 2020-10-28T02:46:16.64
IV.CSNT.HHN. ML:1.5 6.755E-5 0.14 AML other m 2020-10-28T02:46:17.10
IV.FROS.CHE. ML:1.6 0.00012915 0.74 AML other m 2020-10-28T02:46:17.33
IV.ATMI.HHE. ML:2 0.0001675 1.64 AML other m 2020-10-28T02:46:20.88
IV.CASP.HHE. ML:1.4 5.025E-5 0.68 AML other m 2020-10-28T02:46:20.54
IV.ATMI.HHN. ML:2.1 0.0002455 1.62 AML other m 2020-10-28T02:46:21.08
IV.CASP.HHN. ML:1.3 3.59E-5 0.34 AML other m 2020-10-28T02:46:21.12
IV.MURB.HHN. ML:2.6 0.0005105 0.24 AML other m 2020-10-28T02:46:27.30
IV.MURB.HHE. ML:2.3 0.000267 0.3 AML other m 2020-10-28T02:46:28.37
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