Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.7 on date 26-08-2021 and time 01:40:36 (Italy) in region 3 km E Chiusdino (SI)

A magnitude ML 0.7 earthquake occured in region: 3 km E Chiusdino (SI), on

  • 25-08-2021 23:40:36 (UTC)
  • 26-08-2021 01:40:36 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.1430, 11.1230 at 8 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
Chiusdino SI 3 1903 1903
Monticiano SI 5 1571 3474
Montieri GR 9 1204 4678
Radicondoli SI 15 914 5592
Roccastrada GR 15 9199 14791
Sovicille SI 18 10116 24907
Castelnuovo di Val di Cecina PI 19 2231 27138

Municipalities with at least 50000 inhabitants

An earthquake occurred to
26 Km SW of Siena (53903 inhabitants)
42 Km N of Grosseto (82087 inhabitants)
69 Km S of Scandicci (50609 inhabitants)
71 Km S of Firenze (382808 inhabitants)
71 Km SW of Arezzo (99543 inhabitants)
80 Km SE of Livorno (159219 inhabitants)
82 Km S of Prato (191150 inhabitants)
86 Km SE of Pisa (89158 inhabitants)
90 Km S of Pistoia (90315 inhabitants)
93 Km SE of Lucca (89046 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 0.7 2021-08-25
23:40:36		 43.1427 11.123 8 2021-08-26
00:14:34		 Sala Sismica INGV-Roma 94639431
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-25 23:40:36 ± 0.12
Latitude 43.1427 ± 0.0072
Longitude 11.1230 ± 0.0123
Depth (km) 8 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 94639431

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1026
Semi-minor axis of confidence ellipse (meter) 643
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 305
Circular confidence region, given by single value of horizontal uncertainty (meter) 1030.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 120
Number of associated phases, regardless of their use for origin computation 21
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.32
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.39930
Number of stations at which the event was observed 17
Number of stations from which data was used for origin computation 6
Magnitude information

ML:0.7

Field Value
Value 0.7
Uncertainty 0.1
Num. used stations 4
Type of magnitude ML
Reference to an origin 94639431
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-26 00:14:34
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SPS2.HHZ. 2021-08-25T23:41:54.91 3.0 positive manual Pg 19.42 0
IV.MCRV.HHZ. 2021-08-25T23:41:54.54 3.0 undecidable manual Sn -4.91 0
GU.TRAV.HHZ. 2021-08-25T23:41:52.38 3.0 undecidable manual Sn 3.91 0
IV.CMDO.HHZ. 2021-08-25T23:41:47.47 3.0 negative manual Pn -1.88 0
IV.GIZZ.HHZ. 2021-08-25T23:41:38.60 3.0 positive manual Pn 0.19 0
IV.MESG.HHZ. 2021-08-25T23:41:38.18 3.0 undecidable manual Pn 6.09 0
GU.BURY.HHZ. 2021-08-25T23:41:05.36 3.0 undecidable manual Pn 0.59 0
IV.PCRO.HNZ. 2021-08-25T23:41:00.34 3.0 undecidable manual Sn 2.28 0
IV.TST02.HHZ. 2021-08-25T23:40:55.37 3.0 negative manual Pn 0.02 0
IV.CRTC.HHZ. 2021-08-25T23:40:51.98 3.0 undecidable manual Sn 0.26 0
IV.ARCI.HHZ. 2021-08-25T23:40:50.54 0.3 undecidable manual S 138 43.1235 50 -0.44 67
IV.CASP.HHZ. 2021-08-25T23:40:45.35 0.1 undecidable manual P 208 44.3223 50 0.38 90
IV.ARCI.HHZ. 2021-08-25T23:40:44.83 0.1 undecidable manual P 138 43.1235 50 0.04 97
IV.RIBO.EHZ.01 2021-08-25T23:40:44.35 0.3 undecidable manual S 196 22.3554 110 -0.22 73
IV.CSNT.HHE. 2021-08-25T23:40:44.00 0.3 undecidable manual P 20 39.0276 50 -0.17 71
IV.TRIF.CHZ. 2021-08-25T23:40:42.73 0.3 undecidable manual S 260 18.0708 114 -0.47 70
IV.RIBO.EHZ.01 2021-08-25T23:40:41.41 0.1 undecidable manual P 196 22.3554 110 0.32 95
IV.TRIF.CHZ. 2021-08-25T23:40:40.40 0.1 undecidable manual P 260 18.0708 114 0.11 100
IV.FROS.CHZ. 2021-08-25T23:40:40.08 0.3 undecidable manual S 20 7.881 135 -0.14 76
IV.FROS.CHZ. 2021-08-25T23:40:38.77 0.1 undecidable manual P 20 7.881 135 0.2 100
IV.BRSN.EHZ. 2021-08-25T23:40:32.69 3.0 undecidable manual P -0.14 0
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.FROS.CHN. ML:0.6 0.0000591 0.98 AML other m 2021-08-25T23:40:40.29
IV.FROS.CHE. ML:0.6 0.00005964999999999999 0.42 AML other m 2021-08-25T23:40:40.24
IV.TRIF.CHN. ML:0.8 0.0000583 0.1 AML other m 2021-08-25T23:40:42.90
IV.TRIF.CHE. ML:0.7 0.000043950000000000004 1.72 AML other m 2021-08-25T23:40:43.05
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