Earthquake with magnitude of ML 1.0 on date 22-09-2020 and time 00:42:51 (UTC) in region 8 km N Courmayeur (AO)

A magnitude ML 1.0 earthquake occured in region: 8 km N Courmayeur (AO), on

  • 22-09-2020 00:42:51 (UTC)
  • 22-09-2020 02:42:51 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 45.86, 6.98 at 11 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
Courmayeur AO 8 2807 2807
Pré-Saint-Didier AO 11 1050 3857
Morgex AO 13 2104 5961
La Salle AO 15 2087 8048
Saint-Rhémy-en-Bosses AO 16 338 8386
La Thuile AO 17 761 9147
Saint-Oyen AO 19 203 9350

Municipalities with at least 50000 inhabitants

No Italian municipalities within 100 km from the epicenter with at least 50000 inhabitants.

Recent and historical Seismicity
Seismic hazard
Felt maps
The earthquake effects in MCS scale as obtained from the compiled questionnaire

The earthquake effects in MCS scale as obtained from the compiled questionnaire

This map shows the distribution of the effects of the earthquake on the territory in terms of the MCS (Mercalli-Cancani-Sieberg) intensity scale. The intensities are determined using the data provided in the questionnaire ( that are analysed using robust statistical techniques since they are not verified individually. Specifically, the assignment of MCS intensities greater or equal the VI degree of the MCS scale require opportune in situ verification by professional experts. The purple start shows the epicenter. This map is prepared every so often that the population fill in new questionnaires. The number of questionnaires used to determine the map and the date and time of the last adjournment are shown in the upper right part of the panel.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
ML 1.0 2020-09-22
45.86 6.98 11 2020-09-22
Sala Sismica INGV-Roma 83118751
Preferred location and magnitude until now.
Origin information


Field Value
Time (UTC) 2020-09-22 00:42:51 ± 0.26
Latitude 45.86 ± 0.01
Longitude 6.98 ± 0.02
Depth (km) 11 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 83118751


Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1628
Semi-minor axis of confidence ellipse (meter) 1352
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 301
Circular confidence region, given by single value of horizontal uncertainty (meter) 1630
Confidence level of the uncertainty (%) 68


Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 176
Number of associated phases, regardless of their use for origin computation 10
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.43
Epicentral distance of station closest to the epicenter (degree) 0.03777
Epicentral distance of station farthest from the epicenter (degree) 0.41908
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
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 83118751
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-09-22 00:49:25
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
GU.LSD.HHZ. 2020-09-22T00:43:06.57 0.3 undecidable manual S 165 0.4191 50 -0.37 67
CH.DIX.HHZ. 2020-09-22T00:43:04.77 0.3 undecidable manual S 54 0.3669 50 -0.63 62
GU.LSD.HHZ. 2020-09-22T00:43:01.30 0.6 undecidable manual P 165 0.4191 50 0.68 40
CH.DIX.HHZ. 2020-09-22T00:43:00.05 0.3 undecidable manual P 54 0.3669 50 0.32 68
IV.MRGE.HHZ. 2020-09-22T00:42:57.33 0.3 undecidable manual S 149 0.1097 131 -0.27 72
GU.REMY.HHZ. 2020-09-22T00:42:57.92 0.3 undecidable manual S 102 0.125 127 -0.14 74
GU.REMY.HHZ. 2020-09-22T00:42:55.91 0.1 undecidable manual P 102 0.125 127 0.42 93
GU.BLANC.HHZ. 2020-09-22T00:42:55.37 0.3 undecidable manual S 238 0.0378 158 -0.59 67
IV.MRGE.HHZ. 2020-09-22T00:42:55.53 0.1 undecidable manual P 149 0.1097 131 0.31 96
GU.BLANC.HHZ. 2020-09-22T00:42:54.43 0.1 undecidable manual P 238 0.0378 158 0.15 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
GU.BLANC.HHN. ML:1.4 0.0004545 0.46 AML other m 2020-09-22T00:42:55.83
GU.BLANC.HHE. ML:1.3 0.0003325 0.12 AML other m 2020-09-22T00:42:55.80
IV.MRGE.HHE. ML:1.1 0.0001505 0.16 AML other m 2020-09-22T00:42:57.57
IV.MRGE.HHN. ML:0.9 8.93E-5 0.42 AML other m 2020-09-22T00:42:57.43
GU.REMY.HHE. ML:0.6 3.31E-5 0.6 AML other m 2020-09-22T00:42:58.05
GU.REMY.HHN. ML:0.4 2.6942735E-5 0.64 AML other m 2020-09-22T00:42:58.06
CH.DIX.HHE. ML:1.1 3.9338325E-5 0.99 AML other m 2020-09-22T00:43:05.02
CH.DIX.HHN. ML:0.9 2.45898415E-5 0.17 AML other m 2020-09-22T00:43:05.98
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download