Earthquake with magnitude of ML 0.6 on date 22-08-2021 and time 04:41:23 (Italy) in region Costa Ligure Occidentale (Imperia)

A magnitude ML 0.6 earthquake occured in region: Costa Ligure Occidentale (Imperia), on

  • 22-08-2021 02:41:23 (UTC)
  • 22-08-2021 04:41:23 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.023, 7.638 at 9 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
Pigna IM 10 859 859
Triora IM 11 355 1214
Castel Vittorio IM 11 287 1501
Briga Alta CN 11 39 1540
Molini di Triora IM 12 617 2157
Bajardo IM 15 312 2469
Mendatica IM 15 185 2654
Rocchetta Nervina IM 15 298 2952
Montegrosso Pian Latte IM 15 118 3070
Isolabona IM 16 679 3749
Apricale IM 16 629 4378
Cosio d'Arroscia IM 17 221 4599
Perinaldo IM 18 870 5469
Airole IM 18 407 5876
Olivetta San Michele IM 19 211 6087
Rezzo IM 19 366 6453
Ceriana IM 19 1250 7703
Dolceacqua IM 19 2074 9777
Pornassio IM 20 685 10462
Montalto Ligure IM 20 377 10839
Carpasio IM 20 168 11007

Municipalities with at least 50000 inhabitants

An earthquake occurred to
25 Km NW of Sanremo (54807 inhabitants)
42 Km S of Cuneo (56081 inhabitants)
75 Km W of Savona (61345 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
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 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 (http://www.haisentitoilterremoto.it/) 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
Reviewed
Rev100
ML 0.6 2021-08-22
02:41:23
44.0228 7.6377 9 2021-08-22
03:31:59
Sala Sismica INGV-Roma 94483191
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-22 02:41:23 ± 0.1
Latitude 44.0228 ± 0.0054
Longitude 7.6377 ± 0.0063
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 94483191

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 537
Semi-minor axis of confidence ellipse (meter) 402
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 86
Circular confidence region, given by single value of horizontal uncertainty (meter) 540
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 76
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 16
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.31
Epicentral distance of station closest to the epicenter (degree) 0.07105
Epicentral distance of station farthest from the epicenter (degree) 0.32106
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitude information

ML:0.6

Field Value
Value 0.6
Uncertainty 0.3
Num. used stations 18
Type of magnitude ML
Reference to an origin 94483191
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-22 03:31:59
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
GU.RORO.HHZ. 2021-08-22T02:41:35.86 0.3 undecidable manual S 74 0.3211 50 -0.46 66
GU.STV.HHZ. 2021-08-22T02:41:35.68 0.3 undecidable manual S 315 0.3148 50 -0.47 65
GU.BURY.HHZ. 2021-08-22T02:41:34.02 0.3 undecidable manual S 194 0.2473 109 0.04 73
GU.ENR.HHZ. 2021-08-22T02:41:34.21 0.3 undecidable manual S 323 0.2599 108 -0.22 70
GU.GBOS.HHZ. 2021-08-22T02:41:34.30 0.3 undecidable manual S 33 0.2626 108 -0.23 70
GU.IMI.HHZ. 2021-08-22T02:41:32.42 0.3 undecidable manual S 121 0.2149 111 -0.4 68
GU.STV.HHZ. 2021-08-22T02:41:31.38 0.3 undecidable manual P 315 0.3148 50 0.39 67
GU.RORO.HHZ. 2021-08-22T02:41:31.36 0.3 undecidable manual P 74 0.3211 50 0.28 68
GU.GBOS.HHZ. 2021-08-22T02:41:30.44 0.3 undecidable manual P 33 0.2626 108 0.39 67
GU.ENR.HHZ. 2021-08-22T02:41:30.46 0.3 undecidable manual P 323 0.2599 108 0.46 66
GU.IMI.HHZ. 2021-08-22T02:41:29.20 0.3 undecidable manual P 121 0.2149 111 0.13 72
GU.BURY.HHZ. 2021-08-22T02:41:29.96 0.3 undecidable manual P 194 0.2473 109 0.23 70
GU.MGRO.HHZ. 2021-08-22T02:41:29.67 0.3 undecidable manual S 81 0.1241 124 -0.01 75
GU.MGRO.HHZ. 2021-08-22T02:41:27.56 0.3 undecidable manual P 81 0.1241 124 0.31 70
FR.SAOF.HHZ.00 2021-08-22T02:41:27.62 0.3 undecidable manual S 239 0.071 139 -0.52 68
FR.SAOF.HHZ.00 2021-08-22T02:41:26.41 0.1 undecidable manual P 239 0.071 139 0.04 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
FR.SAOF.HHE.00 ML:0.7 6.9845915E-5 0.1808 AML other m 2021-08-22T02:41:27.69
FR.SAOF.HHN.00 ML:0.7 7.5451675E-5 0.2 AML other m 2021-08-22T02:41:28.69
GU.MGRO.HHN. ML:0.2 1.7210275E-5 0.16 AML other m 2021-08-22T02:41:29.98
GU.MGRO.HHE. ML:0.3 1.9306595E-5 0.2992 AML other m 2021-08-22T02:41:31.33
GU.ENR.HHE. ML:0.6 1.754E-5 0.16 AML other m 2021-08-22T02:41:34.49
GU.ENR.HHN. ML:0.6 2.0237101E-5 0.16 AML other m 2021-08-22T02:41:34.49
GU.MGRO.HNE. ML:0.9 8.243134E-5 1.4496 AML other m 2021-08-22T02:41:29.67
GU.MGRO.HNN. ML:0.8 6.6327355E-5 1.72 AML other m 2021-08-22T02:41:29.55
GU.IMI.HHE. ML:0.6 2.2841455E-5 0.2 AML other m 2021-08-22T02:41:33.62
GU.IMI.HHN. ML:0.6 2.36528105E-5 0.1792 AML other m 2021-08-22T02:41:33.22
GU.BURY.HHE. ML:0.6 1.851838E-5 0.7392 AML other m 2021-08-22T02:41:34.72
GU.BURY.HHN. ML:0.4 1.2675865E-5 0.2112 AML other m 2021-08-22T02:41:34.21
GU.BURY.HNE. ML:1.1 6.4252125E-5 1.2288 AML other m 2021-08-22T02:41:35.31
GU.BURY.HNN. ML:0.9 3.831678E-5 1.2512 AML other m 2021-08-22T02:41:34.77
GU.GBOS.HHE. ML:0 6.7471435E-6 0.1008 AML other m 2021-08-22T02:41:34.58
GU.GBOS.HHN. ML:0 6.4913285E-6 0.0992 AML other m 2021-08-22T02:41:34.68
GU.STV.HHE. ML:0.4 1.182459E-5 0.2 AML other m 2021-08-22T02:41:36.51
GU.STV.HHN. ML:0.4 1.18666015E-5 0.28 AML other m 2021-08-22T02:41:36.62
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