Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 04-12-2021 and time 00:35:51 (UTC) in region Confine Italia Svizzera (SVIZZERA)

A magnitude ML 1.1 earthquake occured in region: Confine Italia Svizzera (SVIZZERA), on

  • 04-12-2021 00:35:51 (UTC)
  • 04-12-2021 01:35:51 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 46.2720, 8.0820 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
Trasquera VB 12 194 194
Varzo VB 15 2046 2240
Baceno VB 18 918 3158
Bognanco VB 19 219 3377
Crodo VB 19 1404 4781
Premia VB 20 564 5345

Municipalities with at least 50000 inhabitants

An earthquake occurred to
76 Km NW of Varese (80799 inhabitants)
87 Km NW of Gallarate (53343 inhabitants)
93 Km NW of Como (84495 inhabitants)
94 Km NW of Busto Arsizio (83106 inhabitants)
99 Km NW of Legnano (60262 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 2021-12-04
00:35:51		 46.2717 8.0822 8 2021-12-04
00:46:11		 Sala Sismica INGV-Roma 98107501
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-12-04 00:35:51 ± 0.17
Latitude 46.2717 ± 0.0072
Longitude 8.0822 ± 0.0065
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 98107501

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 748
Semi-minor axis of confidence ellipse (meter) 520
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 163
Circular confidence region, given by single value of horizontal uncertainty (meter) 750.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 133
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.15
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.86785
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 9
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 12
Type of magnitude ML
Reference to an origin 98107501
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-12-04 00:46:11
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.IMI.HHZ. 2021-12-04T00:36:36.52 3.0 undecidable manual Pg 4.22 0
IV.VOBA.EHZ. 2021-12-04T00:36:26.10 3.0 positive manual Pn 0.16 0
IV.SARZ.HHZ. 2021-12-04T00:36:22.99 3.0 negative manual P 1.86 0
GU.TRAV.HHZ. 2021-12-04T00:36:18.11 1.0 undecidable manual S 197 88.1451 50 -0.19 44
CH.MUGIO.HHZ. 2021-12-04T00:36:16.79 1.0 undecidable manual S 117 83.3499 50 -0.24 44
CH.DIX.HHZ. 2021-12-04T00:36:09.67 0.6 undecidable manual S 248 55.9995 50 -0.04 96
IV.MRGE.HHZ. 2021-12-04T00:36:08.49 1.0 undecidable manual P 235 96.3258 50 0.16 43
CH.FUSIO.HHZ. 2021-12-04T00:36:07.61 0.6 undecidable manual S 65 48.9177 50 -0.22 94
GU.TRAV.HHZ. 2021-12-04T00:36:07.08 1.0 undecidable manual P 197 88.1451 50 0.02 45
CH.MUGIO.HHZ. 2021-12-04T00:36:06.69 0.6 undecidable manual P 117 83.3499 50 0.36 85
GU.CIRO.HHE. 2021-12-04T00:36:06.51 1.0 undecidable manual P 208 84.249 50 0.06 45
CH.BNALP.HHE. 2021-12-04T00:36:04.27 1.0 undecidable manual P 21 71.373 50 -0.21 45
IV.VARE.HHE. 2021-12-04T00:36:04.43 0.6 undecidable manual P 130 69.375 50 0.27 90
CH.DIX.HHZ. 2021-12-04T00:36:02.19 0.6 negative manual P 248 55.9995 50 0.09 95
CH.MMK.HHZ. 2021-12-04T00:36:00.62 1.0 undecidable manual S 200 26.1516 108 -0.6 44
CH.FUSIO.HHZ. 2021-12-04T00:36:00.90 1.0 undecidable manual P 65 48.9177 50 -0.11 48
CH.MMK.HHZ. 2021-12-04T00:35:57.31 0.6 positive manual P 200 26.1516 108 0.11 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
CH.MMK.HHE. ML:0.0 0.000015874935 0.14 AML other m 2021-12-04T00:36:00.60
CH.MMK.HHN. ML:0.0 0.00001908518 0.14 AML other m 2021-12-04T00:36:01.44
CH.FUSIO.HHE. ML:0.6 0.000012261599000000002 0.11 AML other m 2021-12-04T00:36:08.10
CH.FUSIO.HHN. ML:0.7 0.000014753857 0.12 AML other m 2021-12-04T00:36:08.73
CH.DIX.HHE. ML:1.3 0.000043863945 0.32 AML other m 2021-12-04T00:36:10.78
CH.DIX.HHN. ML:1.4 0.000053114509999999995 0.21 AML other m 2021-12-04T00:36:10.38
CH.MUGIO.HHE. ML:0.9 0.0000105972725 0.26 AML other m 2021-12-04T00:36:18.37
CH.MUGIO.HHN. ML:0.9 0.000011820496 0.17 AML other m 2021-12-04T00:36:17.49
GU.TRAV.HHE. ML:1.2 0.000019393504999999997 0.12 AML other m 2021-12-04T00:36:20.75
GU.TRAV.HHN. ML:1.3 0.000025726875000000004 0.22 AML other m 2021-12-04T00:36:23.05
IV.MRGE.HHE. ML:1.3 0.000018852969 1.58 AML other m 2021-12-04T00:36:42.94
IV.MRGE.HHN. ML:1.4 0.000023335076000000004 0.98 AML other m 2021-12-04T00:36:16.30
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