Earthquake with magnitude of ML 1.1 on date 05-09-2020 and time 11:35:33 (UTC) in region 1 km N Montieri (GR)

A magnitude ML 1.1 earthquake occured in region: 1 km N Montieri (GR), on

  • 05-09-2020 11:35:33 (UTC)
  • 05-09-2020 13:35:33 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.14, 11.018 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Montieri GR 1 1204 1204
Chiusdino SI 6 1903 3107
Castelnuovo di Val di Cecina PI 12 2231 5338
Monterotondo Marittimo GR 13 1371 6709
Monticiano SI 13 1571 8280
Radicondoli SI 14 914 9194
Massa Marittima GR 14 8375 17569
Roccastrada GR 19 9199 26768

Municipalities with at least 50000 inhabitants

An earthquake occurred to
32 Km SW of Siena (53903 inhabitants)
43 Km N of Grosseto (82087 inhabitants)
70 Km S of Scandicci (50609 inhabitants)
73 Km S of Firenze (382808 inhabitants)
73 Km SE of Livorno (159219 inhabitants)
79 Km W of Arezzo (99543 inhabitants)
81 Km SE of Pisa (89158 inhabitants)
83 Km S of Prato (191150 inhabitants)
89 Km S of Pistoia (90315 inhabitants)
89 Km SE of Lucca (89046 inhabitants)
Recent and historical seismicity
Seismic hazard
Felt maps
Preliminary map of the earthquake effects from the web questionnaire

Preliminary map of the earthquake effects from the web questionnaire

This map shows the distribution of earthquake resentment in the area, expressed in terms of intensity on the MCS scale (Mercalli-Cancani-Sieberg). Intensities are determined using data from questionnaires collected on the website The intensities shown are determined considering all the reports received from each municipality, and are all the more reliable the greater the number of questionnaires. The collected data are subjected to an automatic statistical filter, but are not checked individually. In particular, intensities greater than or equal to the VI degree of the MCS or EMS scale require on-site verification by specialized personnel. The black star is the epicenter of the earthquake that occurred. This map is updated every time citizens fill out new questionnaires. The number of questionnaires processed to obtain this map, the date and time of the last update are shown at the top right.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
ML 1.1 2020-09-05
43.1403 11.0178 10 2020-09-05
Sala Sismica INGV-Roma 82644831
Preferred location and magnitude until now.
Origin information


Field Value
Time (UTC) 2020-09-05 11:35:33 ± 0.16
Latitude 43.1403 ± 0.0126
Longitude 11.0178 ± 0.0173
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 82644831


Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1812
Semi-minor axis of confidence ellipse (meter) 251
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 313
Circular confidence region, given by single value of horizontal uncertainty (meter) 1810
Confidence level of the uncertainty (%) 68


Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 138
Number of associated phases, regardless of their use for origin computation 9
Number of defining phases 9
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.39
Epicentral distance of station closest to the epicenter (degree) 0.08813
Epicentral distance of station farthest from the epicenter (degree) 0.38671
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitude information


Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 6
Type of magnitude ML
Reference to an origin 82644831
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-09-05 13:17:41
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.CSNT.HHN. 2020-09-05T11:35:47.71 0.6 undecidable manual S 31 0.3867 50 -0.33 46
IV.CASP.HHZ. 2020-09-05T11:35:46.90 0.3 undecidable manual S 198 0.3669 50 -0.53 67
IV.CSNT.HHN. 2020-09-05T11:35:42.40 0.3 undecidable manual P 31 0.3867 50 0.38 69
IV.CASP.HHZ. 2020-09-05T11:35:41.90 0.3 undecidable manual P 198 0.3669 50 0.23 71
IV.FROS.CHZ. 2020-09-05T11:35:39.03 0.3 undecidable manual S 55 0.1223 125 -0.54 70
IV.RIBO.EHZ.01 2020-09-05T11:35:38.69 0.1 undecidable manual P 174 0.1925 114 0.21 99
IV.TRIF.CHZ. 2020-09-05T11:35:38.28 0.1 undecidable manual S 253 0.0881 135 -0.26 100
IV.FROS.CHZ. 2020-09-05T11:35:37.39 0.1 undecidable manual P 55 0.1223 125 0.26 99
IV.TRIF.CHZ. 2020-09-05T11:35:36.79 0.1 undecidable manual P 253 0.0881 135 0.25 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.FROS.CHN. ML:1.2 0.000158 0.38 AML other m 2020-09-05T11:35:39.63
IV.TRIF.CHE. ML:1.2 0.00022770265 0.1152 AML other m 2020-09-05T11:35:38.72
IV.TRIF.CHN. ML:1.3 0.00026519225 0.1024 AML other m 2020-09-05T11:35:38.41
IV.FROS.CHE. ML:0.8 7.0467865E-5 0.2432 AML other m 2020-09-05T11:35:41.87
IV.RIBO.EHE.01 ML:0.6 2.5953035E-5 0.3008 AML other m 2020-09-05T11:35:45.86
IV.CASP.HHN. ML:1.1 4.1807225E-5 0.7424 AML other m 2020-09-05T11:35:48.66
IV.CASP.HHE. ML:1 3.45746E-5 0.896 AML other m 2020-09-05T11:35:50.94
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download