Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 18-07-2021 and time 14:05:11 (UTC) in region 2 km N Santa Fiora (GR)

A magnitude ML 1.1 earthquake occured in region: 2 km N Santa Fiora (GR), on

  • 18-07-2021 14:05:11 (UTC)
  • 18-07-2021 16:05:11 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.8520, 11.5950 at 7 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.

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
Santa Fiora GR 2 2622 2622
Arcidosso GR 5 4285 6907
Castel del Piano GR 7 4690 11597
Abbadia San Salvatore SI 8 6444 18041
Piancastagnaio SI 8 4230 22271
Seggiano GR 9 961 23232
Roccalbegna GR 10 1044 24276
Castell'Azzara GR 12 1476 25752
Semproniano GR 14 1059 26811
Radicofani SI 15 1097 27908
Cinigiano GR 17 2618 30526
Castiglione d'Orcia SI 17 2346 32872

Municipalities with at least 50000 inhabitants

An earthquake occurred to
41 Km E of Grosseto (82087 inhabitants)
56 Km SE of Siena (53903 inhabitants)
64 Km NW of Viterbo (67173 inhabitants)
71 Km W of Perugia (166134 inhabitants)
72 Km SW of Arezzo (99543 inhabitants)
86 Km N of Civitavecchia (52991 inhabitants)
91 Km W of Foligno (57155 inhabitants)
92 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
Reviewed
Rev100 		ML 1.1 2021-07-18
14:05:11		 42.8523 11.5948 7 2021-07-18
14:11:46		 Sala Sismica INGV-Roma 92920861
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-07-18 14:05:11 ± 0.08
Latitude 42.8523 ± 0.0054
Longitude 11.5948 ± 0.0037
Depth (km) 7 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 92920861

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 567
Semi-minor axis of confidence ellipse (meter) 290
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 181
Circular confidence region, given by single value of horizontal uncertainty (meter) 570.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 72
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 16
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) 0.04676
Epicentral distance of station farthest from the epicenter (degree) 0.54859
Number of stations at which the event was observed 10
Number of stations from which data was used for origin computation 10
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.1
Num. used stations 2
Type of magnitude ML
Reference to an origin 92920861
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-07-18 14:11:46
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CAFI.HNN. 2021-07-18T14:05:22.28 0.1 undecidable manual P 30 60.8946 50 -0.25 88
IV.FROS.CHN. 2021-07-18T14:05:21.17 0.1 undecidable manual P 318 53.3022 50 -0.19 90
IV.SACS.HHZ. 2021-07-18T14:05:16.76 0.1 undecidable manual P 91 25.5522 106 0.16 95
TV.SF03.EHZ. 2021-07-18T14:05:15.17 0.1 undecidable manual S 127 9.1797 129 -0.19 98
IV.ARCI.HHZ. 2021-07-18T14:05:15.42 0.1 undecidable manual S 270 9.6792 127 -0.08 100
IV.MCIV.CHZ. 2021-07-18T14:05:15.46 0.1 undecidable manual S 141 10.5783 125 -0.27 96
TV.SF04.EHZ. 2021-07-18T14:05:14.36 0.1 undecidable manual S 109 5.6943 143 -0.13 99
TV.SF14.HHZ. 2021-07-18T14:05:14.00 0.1 undecidable manual P 172 10.878 124 0.1 99
TV.SF11.HHZ. 2021-07-18T14:05:14.73 0.1 undecidable manual S 75 7.0929 136 -0.08 100
TV.SF01.EHZ. 2021-07-18T14:05:14.21 0.1 undecidable manual S 210 5.1948 145 -0.18 98
IV.MCIV.CHZ. 2021-07-18T14:05:13.98 0.1 undecidable manual P 141 10.5783 125 0.14 98
TV.SF01.EHZ. 2021-07-18T14:05:13.22 0.1 undecidable manual P 210 5.1948 145 0.15 99
TV.SF04.EHZ. 2021-07-18T14:05:13.32 0.1 undecidable manual P 109 5.6943 143 0.19 98
TV.SF03.EHZ. 2021-07-18T14:05:13.86 0.1 undecidable manual P 127 9.1797 129 0.23 97
IV.ARCI.HHZ. 2021-07-18T14:05:13.85 0.1 undecidable manual P 270 9.6792 127 0.14 98
TV.SF11.HHZ. 2021-07-18T14:05:13.50 0.1 undecidable manual P 75 7.0929 136 0.19 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ARCI.HHE. ML:1.2 0.00022499999999999997 0.42 AML other m 2021-07-18T14:05:15.75
IV.ARCI.HHN. ML:1.1 0.0001835 0.38 AML other m 2021-07-18T14:05:16.40
TV.SF01.EHE. ML:0.0 0.0020353940000000003 0.1024 AML other m 2021-07-18T14:05:14.25
TV.SF01.EHN. ML:0.0 0.0019307425 0.1984 AML other m 2021-07-18T14:05:14.31
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