Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.8 on date 27-10-2020 and time 20:27:19 (Italy) in region 2 km SW Castiglione d'Orcia (SI)

A magnitude ML 1.8 earthquake occured in region: 2 km SW Castiglione d'Orcia (SI), on

  • 27-10-2020 19:27:19 (UTC)
  • 27-10-2020 20:27:19 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.99, 11.59 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.

Hai sentito il terremoto? Clicca qui

Did you feel it? Fill in the questionnaire.

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 8 2662 5008
Seggiano GR 8 961 5969
Montalcino SI 11 5093 11062
Pienza SI 12 2107 13169
Castel del Piano GR 12 4690 17859
Abbadia San Salvatore SI 14 6444 24303
Arcidosso GR 14 4285 28588
Radicofani SI 18 1097 29685
Piancastagnaio SI 18 4230 33915
San Giovanni d'Asso SI 18 853 34768
Santa Fiora GR 18 2622 37390
Buonconvento SI 19 3173 40563
Montepulciano SI 19 14097 54660
Cinigiano GR 20 2618 57278

Municipalities with at least 50000 inhabitants

An earthquake occurred to
42 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 1.8 2020-10-27
19:27:19		 42.99 11.59 11 2021-02-26
14:56:08		 Bollettino Sismico Italiano INGV 85010901
Reviewed
Rev100 		ML 1.9 2020-10-27
19:27:19		 43.02 11.59 8 2020-10-27
19:40:43		 Sala Sismica INGV-Roma 84188791
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-10-27 19:27:19 ± 0.1
Latitude 42.99 ± 0.00
Longitude 11.59 ± 0.00
Depth (km) 11 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 85010901

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 415
Semi-minor axis of confidence ellipse (meter) 158
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 272
Circular confidence region, given by single value of horizontal uncertainty (meter) 420
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 46
Number of associated phases, regardless of their use for origin computation 40
Number of defining phases 40
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) 0.1385
Epicentral distance of station farthest from the epicenter (degree) 0.89303
Number of stations at which the event was observed 26
Number of stations from which data was used for origin computation 26
Magnitudes information

ML:1.9

Field Value
Value 1.9
Uncertainty 0.3
Num. used stations 43
Type of magnitude ML
Reference to an origin 84188791
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-10-27 19:40:43

ML:1.8

Field Value
Value 1.8
Uncertainty 0.3
Num. used stations 37
Type of magnitude ML
Reference to an origin 85010901
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2020-11-25 15:12:58
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.ATMI.HHZ. 2020-10-27T19:27:39.70 0.6 undecidable manual S 55 0.598 50 0.2 44
IV.CASP.HHZ. 2020-10-27T19:27:39.35 0.6 undecidable manual S 250 0.5711 50 0.64 39
IV.TRIF.CHZ. 2020-10-27T19:27:37.30 0.6 undecidable manual S 284 0.5198 50 0.11 46
IV.RINC.HHN. 2020-10-27T19:27:36.21 0.3 undecidable manual P 1 0.893 50 0.19 62
IV.RUFI.EHE. 2020-10-27T19:27:35.67 0.3 undecidable manual P 356 0.8472 50 0.44 60
IV.APEC.HHZ. 2020-10-27T19:27:35.09 0.1 undecidable manual P 46 0.8247 50 0.24 83
IV.PARC.HHZ. 2020-10-27T19:27:34.32 0.3 undecidable manual P 35 0.8058 50 -0.2 63
IV.ASQU.HHE. 2020-10-27T19:27:34.52 0.3 undecidable manual P 10 0.8157 50 -0.17 64
IV.ATVO.HHZ. 2020-10-27T19:27:33.01 0.1 positive manual P 56 0.7078 50 0.15 87
IV.ATPI.EHZ. 2020-10-27T19:27:33.38 0.3 undecidable manual P 52 0.7455 50 -0.11 65
IV.MGAB.HHZ. 2020-10-27T19:27:33.38 1.0 undecidable manual S 102 0.3867 50 0.12 23
IV.RIBO.EHZ.01 2020-10-27T19:27:33.18 0.6 undecidable manual S 264 0.4029 50 -0.56 42
IV.SSP9.EHZ. 2020-10-27T19:27:33.21 0.3 undecidable manual P 34 0.6997 50 0.5 61
IV.CRE.HHZ. 2020-10-27T19:27:32.26 0.1 undecidable manual P 22 0.6772 50 -0.07 89
IV.ATMI.HHZ. 2020-10-27T19:27:31.12 0.1 undecidable manual P 55 0.598 50 0.15 89
IV.CASP.HHZ. 2020-10-27T19:27:30.73 0.3 undecidable manual P 250 0.5711 50 0.22 66
IV.SACS.HHZ. 2020-10-27T19:27:30.00 0.6 undecidable manual S 122 0.2716 50 0.15 48
IV.TRIF.CHZ. 2020-10-27T19:27:29.93 0.3 undecidable manual P 284 0.5198 50 0.3 66
TV.SF14.HHN. 2020-10-27T19:27:28.69 0.3 undecidable manual S 176 0.2383 50 -0.16 72
IV.CSNT.HHZ. 2020-10-27T19:27:28.89 0.1 undecidable manual P 335 0.5288 50 -0.89 72
IV.RIBO.EHZ.01 2020-10-27T19:27:27.75 0.1 positive manual P 264 0.4029 50 0.11 94
IV.CAFI.HHZ. 2020-10-27T19:27:27.63 0.1 undecidable manual P 39 0.4317 50 -0.5 86
IV.ARCI.HHZ. 2020-10-27T19:27:27.14 0.6 undecidable manual S 212 0.1655 50 0.44 46
IV.MCIV.CHZ. 2020-10-27T19:27:27.96 0.6 undecidable manual S 164 0.2221 50 -0.42 45
TV.SF01.EHZ. 2020-10-27T19:27:27.05 0.6 undecidable manual S 187 0.1826 50 -0.15 49
IV.MGAB.HHZ. 2020-10-27T19:27:27.20 0.1 undecidable manual P 102 0.3867 50 -0.16 93
TV.SF03.EHN. 2020-10-27T19:27:27.49 0.3 undecidable manual S 161 0.2014 50 -0.27 71
IV.FROS.CHZ. 2020-10-27T19:27:26.88 0.1 undecidable manual P 304 0.3858 50 -0.47 87
TV.SF13.HHN. 2020-10-27T19:27:26.74 0.3 undecidable manual S 174 0.1754 50 -0.25 71
TV.SF04.EHZ. 2020-10-27T19:27:26.43 0.3 undecidable manual S 163 0.1646 50 -0.23 72
IV.SACS.HHZ. 2020-10-27T19:27:25.65 0.1 undecidable manual P 122 0.2716 50 0.25 93
TV.SF14.HHN. 2020-10-27T19:27:25.01 0.1 positive manual P 176 0.2383 50 0.19 95
TV.SF11.HHZ. 2020-10-27T19:27:25.62 0.3 undecidable manual S 154 0.1385 125 -0.26 72
TV.SF03.EHN. 2020-10-27T19:27:24.40 0.1 positive manual P 161 0.2014 50 0.21 96
IV.MCIV.CHZ. 2020-10-27T19:27:24.75 0.1 positive manual P 164 0.2221 50 0.2 95
TV.SF11.HHZ. 2020-10-27T19:27:23.18 0.1 undecidable manual P 154 0.1385 125 0.08 99
TV.SF01.EHZ. 2020-10-27T19:27:23.97 0.1 positive manual P 187 0.1826 50 0.1 98
IV.ARCI.HHZ. 2020-10-27T19:27:23.56 0.1 positive manual P 212 0.1655 50 -0.02 100
TV.SF04.EHZ. 2020-10-27T19:27:23.50 0.1 undecidable manual P 163 0.1646 50 -0.06 99
TV.SF13.HHN. 2020-10-27T19:27:23.94 0.1 positive manual P 174 0.1754 50 0.19 96
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LRP.EHN. ML:0 6.43222E-6 0.768 AML other m 2020-10-27T19:27:57.63
IV.LRP.EHE. ML:0 2.445871E-5 1.1296 AML other m 2020-10-27T19:28:38.23
IV.ARCI.HHE. ML:1.9 0.000675237 0.3072 AML other m 2020-10-27T19:27:28.87
IV.ARCI.HHN. ML:2 0.00081277595 1.616 AML other m 2020-10-27T19:27:27.88
TV.SF04.EHE. ML:2.8 0.004819015 0.2304 AML other m 2020-10-27T19:27:27.48
TV.SF04.EHN. ML:2.6 0.0031109715 1.7824 AML other m 2020-10-27T19:27:27.94
TV.SF01.EHN. ML:2.8 0.0048310115 0.2304 AML other m 2020-10-27T19:27:28.03
TV.SF01.EHE. ML:2.5 0.002174415 0.2304 AML other m 2020-10-27T19:27:28.17
IV.MCIV.CHE. ML:2 0.00057931045 0.2688 AML other m 2020-10-27T19:27:30.33
IV.MCIV.CHN. ML:2 0.00061595205 0.3584 AML other m 2020-10-27T19:27:29.93
IV.SACS.HHE. ML:1.4 0.00012658761 0.2304 AML other m 2020-10-27T19:27:33.27
IV.SACS.HNE. ML:1.5 0.00015376762 0.3328 AML other m 2020-10-27T19:27:34.52
IV.SACS.HNN. ML:1.6 0.00018229355 0.4608 AML other m 2020-10-27T19:27:35.21
IV.SACS.HHN. ML:1.5 0.00014033833 0.3968 AML other m 2020-10-27T19:27:35.76
IV.FROS.CHE. ML:1.9 0.0002766507 0.32 AML other m 2020-10-27T19:27:35.10
IV.FROS.CHN. ML:1.8 0.00021525945 0.4224 AML other m 2020-10-27T19:27:36.95
IV.MGAB.HNN. ML:1.8 0.0002197439 0.6912 AML other m 2020-10-27T19:27:38.20
IV.MGAB.HHE. ML:1.8 0.0001894506 0.2176 AML other m 2020-10-27T19:27:35.77
IV.MGAB.HHN. ML:1.8 0.0002036573 0.2048 AML other m 2020-10-27T19:27:38.19
IV.MGAB.HNE. ML:1.8 0.00018133253 0.2304 AML other m 2020-10-27T19:27:35.78
IV.CAFI.HHN. ML:1.7 0.00013401165 0.2176 AML other m 2020-10-27T19:27:34.53
IV.CAFI.HHE. ML:1.6 0.0001183453 0.3584 AML other m 2020-10-27T19:27:37.03
IV.RIBO.EHE.01 ML:2.5 0.00096948155 1.8208 AML other m 2020-10-27T19:27:34.92
IV.CSNT.HHN. ML:1.9 0.00017282465 0.1408 AML other m 2020-10-27T19:27:37.66
IV.CSNT.HHE. ML:1.8 0.000127233395 0.192 AML other m 2020-10-27T19:27:37.38
IV.CASP.HHN. ML:1.9 0.0001523151 0.2688 AML other m 2020-10-27T19:27:41.99
IV.CASP.HHE. ML:1.9 0.00014141095 1.744 AML other m 2020-10-27T19:27:39.97
IV.ATMI.HHE. ML:2.3 0.0003613311 0.3456 AML other m 2020-10-27T19:27:45.29
IV.ATMI.HHN. ML:2.4 0.00046043765 1.5648 AML other m 2020-10-27T19:27:41.94
IV.CRE.HHE. ML:1.7 7.091528E-5 0.32 AML other m 2020-10-27T19:27:43.85
IV.CRE.HHN. ML:1.8 8.5746805E-5 0.2304 AML other m 2020-10-27T19:27:43.60
IV.ATVO.HHN. ML:1.6 6.1688615E-5 1.2192 AML other m 2020-10-27T19:27:53.77
IV.ATVO.HHE. ML:2 0.00013616325 0.3328 AML other m 2020-10-27T19:27:47.39
IV.ATPI.EHN. ML:1.8 7.7885665E-5 0.6784 AML other m 2020-10-27T19:27:47.58
IV.ATPI.EHE. ML:1.5 4.6678145E-5 1.2192 AML other m 2020-10-27T19:27:48.90
IV.PARC.HHN. ML:1.7 5.9015045E-5 0.4736 AML other m 2020-10-27T19:27:55.35
IV.PARC.HHE. ML:1.6 4.8879015E-5 1.0272 AML other m 2020-10-27T19:27:55.52
IV.APEC.HHE. ML:1.8 7.423365E-5 0.3968 AML other m 2020-10-27T19:27:54.71
IV.APEC.HHN. ML:1.8 6.381302E-5 0.4608 AML other m 2020-10-27T19:27:54.02
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