Earthquake with magnitude of ML 1.6 on date 31-10-2020 and time 04:58:49 (Italy) in region 3 km N Castiglione d'Orcia (SI)

A magnitude ML 1.6 earthquake occured in region: 3 km N Castiglione d'Orcia (SI), on

  • 31-10-2020 03:58:49 (UTC)
  • 31-10-2020 04:58:49 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.03, 11.61 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.

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 3 2346 2346
San Quirico d'Orcia SI 4 2662 5008
Pienza SI 8 2107 7115
Montalcino SI 11 5093 12208
Seggiano GR 12 961 13169
San Giovanni d'Asso SI 14 853 14022
Montepulciano SI 15 14097 28119
Buonconvento SI 16 3173 31292
Castel del Piano GR 16 4690 35982
Abbadia San Salvatore SI 17 6444 42426
Chianciano Terme SI 18 7105 49531
Arcidosso GR 18 4285 53816
Trequanda SI 18 1254 55070
Radicofani SI 19 1097 56167

Municipalities with at least 50000 inhabitants

An earthquake occurred to
40 Km SE of Siena (53903 inhabitants)
50 Km NE of Grosseto (82087 inhabitants)
53 Km SW of Arezzo (99543 inhabitants)
64 Km W of Perugia (166134 inhabitants)
79 Km NW of Viterbo (67173 inhabitants)
87 Km SE of Firenze (382808 inhabitants)
88 Km SE of Scandicci (50609 inhabitants)
89 Km W of Foligno (57155 inhabitants)
99 Km NW of Terni (111501 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 1.6 2020-10-31
03:58:49
43.03 11.61 8 2020-10-31
04:17:24
Sala Sismica INGV-Roma 84304011
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-10-31 03:58:49 ± 0.13
Latitude 43.03 ± 0.01
Longitude 11.61 ± 0.01
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 84304011

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 905
Semi-minor axis of confidence ellipse (meter) 479
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 162
Circular confidence region, given by single value of horizontal uncertainty (meter) 910
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 73
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 17
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.18
Epicentral distance of station closest to the epicenter (degree) 0.16727
Epicentral distance of station farthest from the epicenter (degree) 0.50272
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 12
Magnitude information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.4
Num. used stations 11
Type of magnitude ML
Reference to an origin 84304011
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-10-31 04:17:24
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.RIBO.EHZ.01 2020-10-31T03:59:04.71 0.3 undecidable manual S 259 0.4227 50 0.1 71
IV.CSNT.HHZ. 2020-10-31T03:58:59.15 0.6 undecidable manual P 332 0.5027 50 -0.23 45
TV.SF01.EHZ. 2020-10-31T03:58:57.93 0.6 undecidable manual S 190 0.2203 109 -0.02 50
IV.CAFI.HHZ. 2020-10-31T03:58:57.46 0.1 undecidable manual P 40 0.3948 50 -0.08 96
IV.ARCI.HHZ. 2020-10-31T03:58:57.49 0.6 undecidable manual S 210 0.2041 110 0.13 49
IV.RIBO.EHZ.01 2020-10-31T03:58:57.95 0.1 positive manual P 259 0.4227 50 -0.06 96
IV.MGAB.HHN. 2020-10-31T03:58:57.37 0.1 undecidable manual P 108 0.3822 50 0.05 97
TV.SF04.EHZ. 2020-10-31T03:58:56.57 0.6 undecidable manual S 170 0.1961 111 -0.51 45
TV.SF11.HHE. 2020-10-31T03:58:55.71 0.6 undecidable manual S 163 0.1673 114 -0.33 48
IV.SACS.HHZ. 2020-10-31T03:58:55.68 1.0 undecidable manual P 130 0.2815 105 0.21 24
TV.SF14.HHE. 2020-10-31T03:58:55.10 0.1 undecidable manual P 180 0.2734 105 -0.21 96
TV.SF03.EHZ. 2020-10-31T03:58:54.65 0.1 undecidable manual P 167 0.232 108 0.23 96
TV.SF01.EHZ. 2020-10-31T03:58:54.14 0.6 positive manual P 190 0.2203 109 -0.03 50
TV.SF13.HHE. 2020-10-31T03:58:54.05 0.1 undecidable manual P 179 0.2104 109 0.09 99
IV.ARCI.HHZ. 2020-10-31T03:58:53.77 0.1 undecidable manual P 210 0.2041 110 -0.06 100
TV.SF11.HHE. 2020-10-31T03:58:53.32 0.1 undecidable manual P 163 0.1673 114 0.25 97
TV.SF04.EHZ. 2020-10-31T03:58:53.94 0.6 undecidable manual P 170 0.1961 111 0.28 48
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF01.EHE. ML:1.8 0.00038 0.26 AML other m 2020-10-31T03:59:01.20
TV.SF04.EHN. ML:2 0.000742 0.26 AML other m 2020-10-31T03:58:59.65
TV.SF04.EHE. ML:2.1 0.000845 0.18 AML other m 2020-10-31T03:59:00.88
IV.ARCI.HHN. ML:1.4 0.000192 0.9 AML other m 2020-10-31T03:59:01.54
IV.ARCI.HHE. ML:1.5 0.000201 0.76 AML other m 2020-10-31T03:59:02.12
IV.CAFI.HHN. ML:1 2.825E-5 0.22 AML other m 2020-10-31T03:59:04.78
IV.CAFI.HHE. ML:1 2.955E-5 0.54 AML other m 2020-10-31T03:59:08.70
IV.CSNT.HHE. ML:1.3 4.335E-5 0.94 AML other m 2020-10-31T03:59:10.12
IV.CSNT.HHN. ML:1.2 3.935E-5 1.78 AML other m 2020-10-31T03:59:10.97
IV.RIBO.EHE.01 ML:1.8 0.00016669745 0.1824 AML other m 2020-10-31T03:59:08.34
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