Earthquake (quarry blast) with magnitude of ML 0.7 on date 21-04-2023 and time 11:50:47 (Italy) in region 2 km W Erli (SV)

A magnitude ML 0.7 (quarry blast) earthquake occured in region: 2 km W Erli (SV), on

  • 21-04-2023 09:50:47 (UTC)
  • 21-04-2023 11:50:47 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.1390, 8.0810 at 0 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

Event type: quarry blast.

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
Erli SV 2 245 245
Castelbianco SV 3 330 575
Castelvecchio di Rocca Barbena SV 3 145 720
Zuccarello SV 4 309 1029
Nasino SV 5 207 1236
Alto CN 7 128 1364
Arnasco SV 7 645 2009
Vendone SV 7 388 2397
Bardineto SV 7 756 3153
Cisano sul Neva SV 8 2085 5238
Garessio CN 8 3244 8482
Balestrino SV 8 595 9077
Onzo SV 8 219 9296
Aquila d'Arroscia IM 9 166 9462
Ortovero SV 9 1586 11048
Ranzo IM 10 557 11605
Toirano SV 10 2644 14249
Caprauna CN 10 104 14353
Calizzano SV 11 1475 15828
Boissano SV 11 2492 18320
Villanova d'Albenga SV 11 2657 20977
Garlenda SV 12 1254 22231
Borghetto d'Arroscia IM 12 456 22687
Casanova Lerrone SV 12 749 23436
Priola CN 13 701 24137
Ceriale SV 13 5561 29698
Borghetto Santo Spirito SV 13 4948 34646
Ormea CN 14 1617 36263
Giustenice SV 14 977 37240
Vessalico IM 14 282 37522
Loano SV 14 11407 48929
Armo IM 14 111 49040
Albenga SV 15 24213 73253
Magliolo SV 15 974 74227
Testico SV 15 196 74423
Stellanello SV 15 808 75231
Tovo San Giacomo SV 16 2582 77813
Pietra Ligure SV 16 8992 86805
Alassio SV 16 10934 97739
Pieve di Teco IM 17 1338 99077
Cesio IM 17 283 99360
Massimino SV 18 113 99473
Rialto SV 18 564 100037
Borgio Verezzi SV 18 2205 102242
Pornassio IM 18 685 102927
Bagnasco CN 19 1035 103962
Osiglia SV 19 444 104406
Calice Ligure SV 19 1730 106136
Caravonica IM 19 282 106418
Villa Faraldi IM 19 444 106862
Viola CN 19 391 107253
Laigueglia SV 19 1810 109063
Chiusanico IM 20 607 109670
Bormida SV 20 387 110057

Municipalities with at least 50000 inhabitants

An earthquake occurred to
37 Km SW of Savona (61345 inhabitants)
42 Km NE of Sanremo (54807 inhabitants)
51 Km SE of Cuneo (56081 inhabitants)
74 Km W of Genova (586655 inhabitants)
85 Km S of Asti (76202 inhabitants)
96 Km SW of Alessandria (93943 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
Bulletin
Rev1000
ML 0.7 2023-04-21
09:50:47
44.1392 8.0807 1 2024-03-01
17:18:20
Bollettino Sismico Italiano INGV 125072611
Reviewed
Rev100
ML 0.8 2023-04-21
09:50:46
44.1057 8.1072 7 2023-04-21
09:59:49
Sala Sismica INGV-Roma 116567931
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-04-21 09:50:47 ± 0.24
Latitude 44.1392 ± 0.0180
Longitude 8.0807 ± 0.0238
Depth (km) 1 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type quarry blast
Origin ID 125072611

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 2450
Semi-minor axis of confidence ellipse (meter) 1320
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 317
Circular confidence region, given by single value of horizontal uncertainty (meter) 2450.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 142
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) 0.51
Epicentral distance of station closest to the epicenter (degree) 0.02878
Epicentral distance of station farthest from the epicenter (degree) 0.52161
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitudes information

ML:0.7

Field Value
Value 0.7
Uncertainty 0.1
Num. used stations 4
Type of magnitude ML
Reference to an origin 125072611
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2024-02-06 14:12:52

ML:0.8

Field Value
Value 0.8
Uncertainty 0.1
Num. used stations 4
Type of magnitude ML
Reference to an origin 116567931
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-04-21 09:59:49
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.PCP.HHZ. 2023-04-21T09:50:57.91 0.6 undecidable manual P 39 57.8976 90 -0.95 37
GU.ENR.HHZ. 2023-04-21T09:50:57.15 0.6 undecidable manual P 281 53.6019 91 -0.86 39
IV.QLNO.HHZ. 2023-04-21T09:50:53.19 0.3 undecidable manual P 46 29.4483 91 0.03 78
GU.MGRO.HHZ. 2023-04-21T09:50:52.09 0.3 undecidable manual P 244 24.1536 91 -0.03 78
GU.IMI.HHZ. 2023-04-21T09:50:52.57 0.3 undecidable manual P 211 29.4483 91 -0.6 68
GU.GBOS.HHZ. 2023-04-21T09:50:52.41 0.3 undecidable manual P 301 22.2555 91 0.68 66
GU.CANO.HHZ. 2023-04-21T09:50:50.48 0.3 undecidable manual P 59 14.5743 92 0.29 76
GU.RORO.HHZ. 2023-04-21T09:50:48.32 0.1 undecidable manual P 201 3.1968 99 0.41 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
GU.CANO.HHN. ML:0.7 0.0000613 1.7 AML other m 2023-04-21T09:50:52.85
GU.CANO.HHE. ML:0.9 0.00009647418 0.416 AML other m 2023-04-21T09:50:53.01
GU.MGRO.HHN. ML:0.6 0.000029121025000000003 0.2752 AML other m 2023-04-21T09:50:57.40
GU.MGRO.HHE. ML:0.7 0.00003715 0.86 AML other m 2023-04-21T09:50:59.81
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