Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 11-12-2020 and time 21:40:59 (Italy) in region 4 km SW Onano (VT)

A magnitude ML 1.1 earthquake occured in region: 4 km SW Onano (VT), on

  • 11-12-2020 20:40:59 (UTC)
  • 11-12-2020 21:40:59 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.6770, 11.7770 at 8 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
Onano VT 4 995 995
Sorano GR 5 3428 4423
Latera VT 7 836 5259
Gradoli VT 8 1353 6612
Grotte di Castro VT 8 2683 9295
Pitigliano GR 10 3818 13113
Proceno VT 10 557 13670
Acquapendente VT 11 5506 19176
San Lorenzo Nuovo VT 11 2091 21267
Valentano VT 12 2868 24135
Castell'Azzara GR 13 1476 25611
Farnese VT 15 1527 27138
Ischia di Castro VT 15 2326 29464
Castel Giorgio TR 17 2131 31595
Bolsena VT 18 3991 35586
Capodimonte VT 18 1731 37317
Piansano VT 18 2079 39396
Cellere VT 19 1188 40584
Marta VT 20 3499 44083

Municipalities with at least 50000 inhabitants

An earthquake occurred to
39 Km NW of Viterbo (67173 inhabitants)
55 Km E of Grosseto (82087 inhabitants)
65 Km N of Civitavecchia (52991 inhabitants)
69 Km SW of Perugia (166134 inhabitants)
72 Km W of Terni (111501 inhabitants)
80 Km SE of Siena (53903 inhabitants)
82 Km W of Foligno (57155 inhabitants)
88 Km S of Arezzo (99543 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 1.1 2020-12-11
20:40:59		 42.6772 11.7773 9 2021-02-26
14:56:17		 Bollettino Sismico Italiano INGV 86831731
Reviewed
Rev100 		ML 1.1 2020-12-11
20:40:59		 42.681 11.7738 9 2020-12-11
20:49:26		 Sala Sismica INGV-Roma 85362801
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-12-11 20:40:59 ± 0.11
Latitude 42.6772 ± 0.0063
Longitude 11.7773 ± 0.0061
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 86831731

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 750
Semi-minor axis of confidence ellipse (meter) 439
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 335
Circular confidence region, given by single value of horizontal uncertainty (meter) 750.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 109
Number of associated phases, regardless of their use for origin computation 20
Number of defining phases 18
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.53690
Number of stations at which the event was observed 11
Number of stations from which data was used for origin computation 9
Magnitudes information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 86831731
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-02-04 16:01:12

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 85362801
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-12-11 20:49:26
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MBFT.HHZ. 2020-12-11T20:42:12.10 3.0 undecidable manual Pn 4.34 0
IV.PESA.HHZ. 2020-12-11T20:41:50.55 3.0 undecidable manual Sg 0.55 0
IV.MAON.HHZ. 2020-12-11T20:41:18.43 0.3 undecidable manual S 243 59.5959 50 -0.08 68
IV.BARO.HNZ. 2020-12-11T20:41:16.21 0.6 undecidable manual S 155 52.6029 50 -0.43 43
IV.MGAB.HHZ. 2020-12-11T20:41:12.67 0.6 undecidable manual S 46 37.7289 50 0 48
IV.MAON.HHZ. 2020-12-11T20:41:10.59 0.3 undecidable manual P 243 59.5959 50 0.09 68
IV.ARCI.HHZ. 2020-12-11T20:41:10.62 0.6 undecidable manual S 308 31.3464 105 -0.22 47
IV.BARO.HNZ. 2020-12-11T20:41:09.63 0.6 undecidable manual P 155 52.6029 50 0.21 45
IV.MGAB.HHZ. 2020-12-11T20:41:07.18 0.1 undecidable manual P 46 37.7289 50 0.05 96
IV.SACS.HHZ. 2020-12-11T20:41:07.78 0.6 undecidable manual S 29 21.867 111 0.06 49
IV.ARCI.HHZ. 2020-12-11T20:41:06.76 0.3 undecidable manual P 308 31.3464 105 0.69 61
TV.SF04.EHZ. 2020-12-11T20:41:06.89 0.3 undecidable manual S 332 19.9689 113 -0.22 71
IV.MCIV.CHZ. 2020-12-11T20:41:05.27 0.6 undecidable manual S 324 13.9749 121 0.03 50
TV.SF14.HHE. 2020-12-11T20:41:05.56 0.3 undecidable manual S 303 15.873 118 -0.25 71
TV.SF03.EHN. 2020-12-11T20:41:05.75 0.6 undecidable manual S 332 15.7731 118 -0.05 50
IV.SACS.HHZ. 2020-12-11T20:41:04.07 0.3 undecidable manual P 29 21.867 111 -0.21 71
TV.SF14.HHE. 2020-12-11T20:41:03.18 0.1 undecidable manual P 303 15.873 118 0.01 100
TV.SF03.EHN. 2020-12-11T20:41:03.24 0.1 undecidable manual P 332 15.7731 118 0.07 99
TV.SF04.EHZ. 2020-12-11T20:41:03.90 0.1 undecidable manual P 332 19.9689 113 -0.03 99
IV.MCIV.CHZ. 2020-12-11T20:41:02.98 0.1 undecidable manual P 324 13.9749 121 0.13 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.MCIV.CHN. ML:1.0 0.00011499999999999999 0.52 AML other m 2020-12-11T20:41:06.23
IV.MCIV.CHE. ML:1.1 0.000129 0.92 AML other m 2020-12-11T20:41:06.94
TV.SF04.EHE. ML:1.5 0.0002465 1.28 AML other m 2020-12-11T20:41:07.93
TV.SF04.EHN. ML:1.7 0.000365 1.28 AML other m 2020-12-11T20:41:07.79
IV.SACS.HHN. ML:1.0 0.000062827915 0.256 AML other m 2020-12-11T20:41:08.40
IV.SACS.HHE. ML:1.1 0.00008685316 0.2432 AML other m 2020-12-11T20:41:08.72
IV.ARCI.HHN. ML:0.5 0.000015826194500000003 0.1408 AML other m 2020-12-11T20:41:13.08
IV.ARCI.HHE. ML:0.6 0.000020525545 0.1792 AML other m 2020-12-11T20:41:13.21
IV.MGAB.HHE. ML:1.2 0.00005399999999999999 0.42 AML other m 2020-12-11T20:41:13.53
IV.MGAB.HHN. ML:1.2 0.00006455 0.54 AML other m 2020-12-11T20:41:14.84
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