Earthquake with magnitude of ML 1.6 on date 28-10-2020 and time 02:23:29 (Italy) in region 3 km SW San Quirico d'Orcia (SI)

A magnitude ML 1.6 earthquake occured in region: 3 km SW San Quirico d'Orcia (SI), on

  • 28-10-2020 01:23:29 (UTC)
  • 28-10-2020 02:23:29 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.04, 11.59 at 3 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
San Quirico d'Orcia SI 3 2662 2662
Castiglione d'Orcia SI 4 2346 5008
Montalcino SI 9 5093 10101
Pienza SI 9 2107 12208
Seggiano GR 12 961 13169
San Giovanni d'Asso SI 13 853 14022
Buonconvento SI 14 3173 17195
Castel del Piano GR 16 4690 21885
Montepulciano SI 17 14097 35982
Trequanda SI 18 1254 37236
Arcidosso GR 19 4285 41521
Abbadia San Salvatore SI 19 6444 47965
Chianciano Terme SI 20 7105 55070

Municipalities with at least 50000 inhabitants

An earthquake occurred to
38 Km SE of Siena (53903 inhabitants)
49 Km NE of Grosseto (82087 inhabitants)
53 Km SW of Arezzo (99543 inhabitants)
65 Km W of Perugia (166134 inhabitants)
81 Km NW of Viterbo (67173 inhabitants)
86 Km SE of Firenze (382808 inhabitants)
87 Km SE of Scandicci (50609 inhabitants)
91 Km W of Foligno (57155 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 2020-10-28
01:23:29
43.04 11.59 3 2020-10-28
01:32:03
Sala Sismica INGV-Roma 84192701
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-10-28 01:23:29 ± 0.11
Latitude 43.04 ± 0.01
Longitude 11.59 ± 0.01
Depth (km) 3 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 84192701

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 638
Semi-minor axis of confidence ellipse (meter) 459
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 91
Circular confidence region, given by single value of horizontal uncertainty (meter) 640
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 41
Number of associated phases, regardless of their use for origin computation 30
Number of defining phases 30
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.36
Epicentral distance of station closest to the epicenter (degree) 0.20325
Epicentral distance of station farthest from the epicenter (degree) 0.80309
Number of stations at which the event was observed 20
Number of stations from which data was used for origin computation 20
Magnitude information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 16
Type of magnitude ML
Reference to an origin 84192701
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-10-28 01:32:03
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.CSNT.HHZ. 2020-10-28T01:23:47.37 0.6 undecidable manual S 333 0.4874 50 -1.09 34
IV.RUFI.EHN. 2020-10-28T01:23:46.54 0.6 undecidable manual P 356 0.8031 50 0.59 39
IV.PARC.HHE. 2020-10-28T01:23:45.49 0.3 undecidable manual P 37 0.7716 50 0.06 68
IV.SSP9.EHZ. 2020-10-28T01:23:44.19 0.3 undecidable manual P 36 0.6655 50 0.58 61
IV.RIBO.EHZ.01 2020-10-28T01:23:44.44 0.6 undecidable manual S 258 0.4074 94 -1.04 35
IV.CAFI.HHZ. 2020-10-28T01:23:44.36 0.6 undecidable manual S 43 0.4002 94 -0.87 38
IV.MURB.HHZ. 2020-10-28T01:23:44.59 0.3 undecidable manual P 71 0.7177 50 0.09 68
IV.CRE.HHN. 2020-10-28T01:23:43.55 0.3 undecidable manual P 24 0.6385 50 0.41 65
IV.FROS.CHZ. 2020-10-28T01:23:43.77 0.6 undecidable manual S 299 0.3606 94 0.08 49
IV.ATMI.HHZ. 2020-10-28T01:23:42.29 0.6 undecidable manual P 59 0.5765 50 0.21 46
IV.CASP.HHZ. 2020-10-28T01:23:42.30 0.3 undecidable manual P 245 0.5846 50 0.07 70
IV.ATMC.EHZ. 2020-10-28T01:23:42.38 0.1 undecidable manual P 47 0.5998 50 -0.11 93
IV.CSNT.HHZ. 2020-10-28T01:23:39.99 0.1 undecidable manual P 333 0.4874 50 -0.57 85
IV.MCIV.CHZ. 2020-10-28T01:23:39.04 0.6 undecidable manual S 166 0.2653 96 -1.01 37
IV.RIBO.EHZ.01 2020-10-28T01:23:38.85 0.1 positive manual P 258 0.4074 94 0.01 98
IV.CAFI.HHZ. 2020-10-28T01:23:38.73 0.1 undecidable manual P 43 0.4002 94 0.04 98
IV.ARCI.HHZ. 2020-10-28T01:23:38.32 0.6 undecidable manual S 204 0.2032 98 0.66 43
TV.SF01.EHZ. 2020-10-28T01:23:38.81 0.6 undecidable manual S 185 0.2257 97 0.29 48
IV.MGAB.HHZ. 2020-10-28T01:23:38.26 0.3 undecidable manual P 108 0.4011 94 -0.45 67
TV.SF03.EHZ. 2020-10-28T01:23:38.44 0.6 undecidable manual S 163 0.2446 96 -0.79 41
IV.FROS.CHZ. 2020-10-28T01:23:38.02 0.1 undecidable manual P 299 0.3606 94 0.21 95
TV.SF04.EHZ. 2020-10-28T01:23:37.31 0.3 undecidable manual S 166 0.2077 97 -0.52 69
TV.SF13.HHE. 2020-10-28T01:23:37.76 0.6 undecidable manual S 174 0.2194 97 -0.52 46
IV.SACS.HHZ. 2020-10-28T01:23:36.86 0.1 undecidable manual P 129 0.2995 95 0.4 93
IV.MCIV.CHZ. 2020-10-28T01:23:35.77 0.1 positive manual P 166 0.2653 96 0.06 100
TV.SF03.EHZ. 2020-10-28T01:23:35.38 0.1 undecidable manual P 163 0.2446 96 0.15 99
TV.SF04.EHZ. 2020-10-28T01:23:34.73 0.1 positive manual P 166 0.2077 97 0.31 96
IV.ARCI.HHZ. 2020-10-28T01:23:34.57 0.3 undecidable manual P 204 0.2032 98 0.25 73
TV.SF01.EHZ. 2020-10-28T01:23:34.95 0.1 undecidable manual P 185 0.2257 97 0.13 99
TV.SF13.HHE. 2020-10-28T01:23:34.93 0.1 undecidable manual P 174 0.2194 97 0.25 97
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF04.EHE. ML:1.9 0.0006255 0.4 AML other m 2020-10-28T01:23:38.91
TV.SF01.EHE. ML:1.7 0.00034 0.22 AML other m 2020-10-28T01:23:39.00
TV.SF01.EHN. ML:2 0.00074 1.78 AML other m 2020-10-28T01:23:39.99
TV.SF04.EHN. ML:2 0.000658 0.26 AML other m 2020-10-28T01:23:39.11
IV.MCIV.CHE. ML:1.4 0.0001365 0.64 AML other m 2020-10-28T01:23:41.30
IV.MCIV.CHN. ML:1.4 0.000119 1.76 AML other m 2020-10-28T01:23:42.99
IV.FROS.CHE. ML:1.4 9.29E-5 0.5 AML other m 2020-10-28T01:23:45.63
IV.FROS.CHN. ML:1.5 0.000113 0.44 AML other m 2020-10-28T01:23:47.83
IV.CAFI.HHN. ML:1 3.39E-5 1.06 AML other m 2020-10-28T01:23:47.68
IV.CAFI.HHE. ML:1.1 3.785E-5 0.32 AML other m 2020-10-28T01:23:48.29
IV.CSNT.HHE. ML:1.4 5.625E-5 0.38 AML other m 2020-10-28T01:23:48.36
IV.CSNT.HHN. ML:1.4 6.225E-5 0.18 AML other m 2020-10-28T01:23:49.04
IV.ATMI.HHN. ML:1.7 9.88E-5 1.68 AML other m 2020-10-28T01:23:52.99
IV.ATMI.HHE. ML:1.7 0.00010215 0.38 AML other m 2020-10-28T01:23:56.35
IV.MURB.HHE. ML:2 0.000124 0.42 AML other m 2020-10-28T01:23:58.05
IV.MURB.HHN. ML:2.2 0.00022 0.26 AML other m 2020-10-28T01:23:59.08
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