Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.8 on date 17-01-2021 and time 21:32:32 (UTC) in region 5 km S Radicofani (SI)

A magnitude ML 0.8 earthquake occured in region: 5 km S Radicofani (SI), on

  • 17-01-2021 21:32:32 (UTC)
  • 17-01-2021 22:32:32 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.8580, 11.7590 at 10 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.

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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
Radicofani SI 5 1097 1097
Piancastagnaio SI 5 4230 5327
Abbadia San Salvatore SI 7 6444 11771
San Casciano dei Bagni SI 10 1632 13403
Castell'Azzara GR 11 1476 14879
Proceno VT 13 557 15436
Santa Fiora GR 14 2622 18058
Acquapendente VT 15 5506 23564
Cetona SI 17 2755 26319
Sarteano SI 17 4717 31036
Arcidosso GR 18 4285 35321
Seggiano GR 18 961 36282
Allerona TR 18 1794 38076
Castel del Piano GR 18 4690 42766
Onano VT 19 995 43761
Sorano GR 20 3428 47189

Municipalities with at least 50000 inhabitants

An earthquake occurred to
54 Km E of Grosseto (82087 inhabitants)
57 Km NW of Viterbo (67173 inhabitants)
58 Km W of Perugia (166134 inhabitants)
62 Km SE of Siena (53903 inhabitants)
69 Km S of Arezzo (99543 inhabitants)
78 Km W of Foligno (57155 inhabitants)
80 Km W of Terni (111501 inhabitants)
85 Km N of Civitavecchia (52991 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
Reviewed
Rev100 		ML 0.8 2021-01-17
21:32:32		 42.8578 11.7588 10 2021-01-17
21:38:08		 Sala Sismica INGV-Roma 86337531
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-01-17 21:32:32 ± 0.09
Latitude 42.8578 ± 0.0117
Longitude 11.7588 ± 0.0086
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 86337531

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1205
Semi-minor axis of confidence ellipse (meter) 771
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 194
Circular confidence region, given by single value of horizontal uncertainty (meter) 1210.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 170
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 13
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) 0.07554
Epicentral distance of station farthest from the epicenter (degree) 0.26440
Number of stations at which the event was observed 7
Number of stations from which data was used for origin computation 7
Magnitude information

ML:0.8

Field Value
Value 0.8
Uncertainty 0.4
Num. used stations 6
Type of magnitude ML
Reference to an origin 86337531
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-01-17 21:38:08
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MGAB.HHZ. 2021-01-17T21:32:43.28 0.6 undecidable manual S 78 29.3484 50 0.01 49
IV.ARCI.HHZ. 2021-01-17T21:32:41.35 0.3 undecidable manual S 268 23.0547 114 -0.2 72
TV.SF14.HHZ. 2021-01-17T21:32:39.43 0.6 undecidable manual S 226 16.3725 122 -0.07 50
IV.ARCI.HHZ. 2021-01-17T21:32:38.22 0.6 negative manual P 268 23.0547 114 0.37 46
IV.MGAB.HHZ. 2021-01-17T21:32:38.61 0.1 undecidable manual P 78 29.3484 50 -0.23 94
TV.SF04.EHZ. 2021-01-17T21:32:37.13 0.6 undecidable manual S 253 8.3805 141 -0.26 49
IV.MCIV.CHZ. 2021-01-17T21:32:37.99 0.6 undecidable manual S 217 11.0778 133 -0.04 51
TV.SF03.EHZ. 2021-01-17T21:32:37.12 0.3 undecidable manual S 224 8.4804 140 -0.31 72
IV.SACS.HHZ. 2021-01-17T21:32:36.07 0.6 undecidable manual P 94 12.2766 130 0.06 50
TV.SF14.HHZ. 2021-01-17T21:32:36.78 0.1 undecidable manual P 226 16.3725 122 0.12 99
TV.SF03.EHZ. 2021-01-17T21:32:35.66 0.1 undecidable manual P 224 8.4804 140 0.19 99
TV.SF04.EHZ. 2021-01-17T21:32:35.70 0.3 positive manual P 253 8.3805 141 0.25 73
IV.MCIV.CHZ. 2021-01-17T21:32:35.93 0.1 positive manual P 217 11.0778 133 0.11 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF04.EHN. ML:1.5 0.0004 0.1 AML other m 2021-01-17T21:32:37.60
TV.SF04.EHE. ML:1.4 0.0003805 0.5 AML other m 2021-01-17T21:32:37.59
IV.MCIV.CHN. ML:0.8 0.00007205 0.14 AML other m 2021-01-17T21:32:38.90
IV.MCIV.CHE. ML:0.8 0.00006945 0.44 AML other m 2021-01-17T21:32:39.59
IV.SACS.HHE. ML:0.6 0.000043934585 0.2176 AML other m 2021-01-17T21:32:39.73
IV.SACS.HHN. ML:0.4 0.000022532245 0.2688 AML other m 2021-01-17T21:32:40.43
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