Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 21-12-2020 and time 08:14:41 (UTC) in region 5 km W Rialto (SV)

A magnitude ML 1.1 earthquake occured in region: 5 km W Rialto (SV), on

  • 21-12-2020 08:14:41 (UTC)
  • 21-12-2020 09:14:41 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 44.2310, 8.2120 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
Rialto SV 5 564 564
Magliolo SV 5 974 1538
Bormida SV 6 387 1925
Osiglia SV 6 444 2369
Giustenice SV 7 977 3346
Calice Ligure SV 7 1730 5076
Tovo San Giacomo SV 8 2582 7658
Calizzano SV 8 1475 9133
Bardineto SV 8 756 9889
Orco Feglino SV 9 890 10779
Mallare SV 10 1146 11925
Murialdo SV 10 841 12766
Boissano SV 11 2492 15258
Pietra Ligure SV 11 8992 24250
Borgio Verezzi SV 11 2205 26455
Toirano SV 12 2644 29099
Loano SV 12 11407 40506
Vezzi Portio SV 12 809 41315
Pallare SV 12 923 42238
Balestrino SV 12 595 42833
Finale Ligure SV 13 11711 54544
Borghetto Santo Spirito SV 13 4948 59492
Erli SV 13 245 59737
Castelvecchio di Rocca Barbena SV 14 145 59882
Massimino SV 14 113 59995
Plodio SV 14 650 60645
Roccavignale SV 15 752 61397
Garessio CN 15 3244 64641
Millesimo SV 15 3383 68024
Ceriale SV 15 5561 73585
Priola CN 15 701 74286
Castelnuovo di Ceva CN 15 110 74396
Zuccarello SV 15 309 74705
Perlo CN 15 116 74821
Cosseria SV 16 1105 75926
Carcare SV 16 5587 81513
Bagnasco CN 16 1035 82548
Altare SV 16 2108 84656
Noli SV 17 2736 87392
Spotorno SV 17 3803 91195
Cisano sul Neva SV 17 2085 93280
Castelbianco SV 17 330 93610
Nucetto CN 17 430 94040
Montezemolo CN 17 259 94299
Quiliano SV 17 7232 101531
Cengio SV 18 3563 105094
Vado Ligure SV 19 8336 113430
Bergeggi SV 19 1129 114559
Battifollo CN 19 219 114778
Priero CN 19 529 115307
Arnasco SV 19 645 115952
Nasino SV 19 207 116159
Cairo Montenotte SV 20 13269 129428

Municipalities with at least 50000 inhabitants

An earthquake occurred to
23 Km W of Savona (61345 inhabitants)
56 Km E of Cuneo (56081 inhabitants)
57 Km NE of Sanremo (54807 inhabitants)
61 Km W of Genova (586655 inhabitants)
74 Km S of Asti (76202 inhabitants)
82 Km SW of Alessandria (93943 inhabitants)
95 Km SE of Moncalieri (57294 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 2020-12-21
08:14:41		 44.2313 8.2118 9 2020-12-21
08:19:04		 Sala Sismica INGV-Roma 85596461
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-12-21 08:14:41 ± 0.24
Latitude 44.2313 ± 0.0189
Longitude 8.2118 ± 0.0251
Depth (km) 9 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 85596461

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 2786
Semi-minor axis of confidence ellipse (meter) 504
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 138
Circular confidence region, given by single value of horizontal uncertainty (meter) 2790.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 125
Number of associated phases, regardless of their use for origin computation 8
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.37
Epicentral distance of station closest to the epicenter (degree) 0.02968
Epicentral distance of station farthest from the epicenter (degree) 0.39031
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 4
Type of magnitude ML
Reference to an origin 85596461
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-12-21 08:19:04
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.PCP.HHZ. 2020-12-21T08:14:50.14 0.3 undecidable manual P 37 43.3233 50 -0.18 68
GU.GBOS.HHZ. 2020-12-21T08:14:48.21 0.3 undecidable manual P 272 29.5482 106 0.15 70
GU.RORO.HHZ. 2020-12-21T08:14:48.16 0.3 undecidable manual S 221 17.5713 116 -0.51 66
IV.QLNO.HHZ. 2020-12-21T08:14:47.48 0.1 undecidable manual S 46 14.7741 120 -0.34 92
GU.RORO.HHZ. 2020-12-21T08:14:45.97 0.3 undecidable manual P 221 17.5713 116 0.16 72
GU.CANO.HHZ. 2020-12-21T08:14:45.02 0.1 undecidable manual S 143 3.2967 159 -0.05 100
IV.QLNO.HHZ. 2020-12-21T08:14:45.60 0.1 undecidable manual P 46 14.7741 120 0.28 93
GU.CANO.HHZ. 2020-12-21T08:14:44.09 0.1 undecidable manual P 143 3.2967 159 0.36 94
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
GU.CANO.HHE. ML:0.0 0.00042249999999999997 0.16 AML other m 2020-12-21T08:14:45.05
IV.QLNO.HHE. ML:1.0 0.0001031 0.92 AML other m 2020-12-21T08:14:47.53
IV.QLNO.HHN. ML:1.0 0.00008885 0.1 AML other m 2020-12-21T08:14:47.75
GU.RORO.HHN. ML:1.4 0.0002055 0.1 AML other m 2020-12-21T08:14:48.33
GU.RORO.HHE. ML:1.1 0.00011888219999999999 0.1216 AML other m 2020-12-21T08:14:48.46
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