Earthquake with magnitude of ML 0.8 on date 27-12-2021 and time 17:23:12 (Italy) in region 2 km W Rialto (SV)

A magnitude ML 0.8 earthquake occured in region: 2 km W Rialto (SV), on

  • 27-12-2021 16:23:12 (UTC)
  • 27-12-2021 17:23:12 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 44.2230, 8.2490 at 10 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

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
Rialto SV 2 564 564
Magliolo SV 3 974 1538
Calice Ligure SV 4 1730 3268
Tovo San Giacomo SV 5 2582 5850
Giustenice SV 6 977 6827
Orco Feglino SV 6 890 7717
Bormida SV 6 387 8104
Osiglia SV 8 444 8548
Borgio Verezzi SV 8 2205 10753
Pietra Ligure SV 9 8992 19745
Mallare SV 9 1146 20891
Vezzi Portio SV 9 809 21700
Finale Ligure SV 10 11711 33411
Boissano SV 10 2492 35903
Bardineto SV 10 756 36659
Loano SV 10 11407 48066
Calizzano SV 11 1475 49541
Toirano SV 11 2644 52185
Pallare SV 12 923 53108
Borghetto Santo Spirito SV 12 4948 58056
Balestrino SV 12 595 58651
Murialdo SV 13 841 59492
Noli SV 14 2736 62228
Spotorno SV 14 3803 66031
Ceriale SV 14 5561 71592
Castelvecchio di Rocca Barbena SV 15 145 71737
Altare SV 15 2108 73845
Erli SV 15 245 74090
Plodio SV 15 650 74740
Quiliano SV 15 7232 81972
Carcare SV 16 5587 87559
Vado Ligure SV 16 8336 95895
Bergeggi SV 16 1129 97024
Roccavignale SV 16 752 97776
Millesimo SV 16 3383 101159
Zuccarello SV 16 309 101468
Cosseria SV 16 1105 102573
Massimino SV 17 113 102686
Cisano sul Neva SV 17 2085 104771
Castelnuovo di Ceva CN 17 110 104881
Garessio CN 18 3244 108125
Perlo CN 18 116 108241
Priola CN 18 701 108942
Castelbianco SV 18 330 109272
Bagnasco CN 19 1035 110307
Cengio SV 19 3563 113870
Montezemolo CN 19 259 114129
Albenga SV 19 24213 138342
Arnasco SV 20 645 138987
Cairo Montenotte SV 20 13269 152256
Nucetto CN 20 430 152686

Municipalities with at least 50000 inhabitants

An earthquake occurred to
21 Km W of Savona (61345 inhabitants)
58 Km NE of Sanremo (54807 inhabitants)
58 Km W of Genova (586655 inhabitants)
59 Km E of Cuneo (56081 inhabitants)
75 Km S of Asti (76202 inhabitants)
82 Km SW of Alessandria (93943 inhabitants)
97 Km SE of Moncalieri (57294 inhabitants)
Recent and historical seismicity

These maps show the seismic activity in different time intervals, before the seismic event to which they refer. Data reported in the first two maps come from the analysis carried out in real time by the personnel of the INGV Operating Rooms, immediately after each earthquake. The third map shows data from 1985 to the date of the earthquake: the locations are reviewed by the seismological analysts of the INGV Italian Seismic Bulletin (Bollettino Sismico Italiano dell’INGV). The localization parameters (hypocentral coordinates and magnitude) are the best possible estimate with the data available to the INGV, but are constantly updated according to further data that become available. The location and magnitude parameters, subsequently reviewed by seismological analysts, may vary.

Earthquakes of the 3 days preceding this event

Earthquakes of the 3 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 0.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 72 hours preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes of the 90 days preceding this event

Earthquakes of the 90 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 2.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 90 days preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes from 1985 to the date of the event

Earthquakes from 1985 to the date of the event

This map shows the earthquake epicenters with magnitude ≥ 3.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, from 1985 to the date of this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes since 1000 AD until 2019

Earthquakes since 1000 AD until 2019

This map shows the epicenters of the historical earthquakes catalogue CPT15 (Catalogo Parametrico dei Terremoti Italiani, 2015 version 3.0, https://doi.org/10.13127/cpti/cpti15.3) since 1000 AD until 2019. The size of the square indicates the different classes of magnitude. For earthquakes with magnitude ≥ 6.0, it is also shown the year of occurrence and the magnitude value. The black and white star is the epicenter of the current earthquake.
Seismic hazard

Seismic hazard maps provide probabilistic estimates of the earthquake ground shaking exceeding a given threshold in a given geographic region within a given time window. Thus, it is not a deterministic prediction - a target that may be never reached given the complexity of the earthquake physical phenomenon - nor of the maximum expected earthquake since this has extremely low probabilities to occur.

In 2004, it was published the seismic hazard map of Italy (http://zonesismiche.mi.ingv.it) that provides a picture of the most hazardous geographic regions. The seismic hazard map of Italy (GdL MPS, 2004; rif. Ordinanza PCM del 28 aprile 2006, n. 3519, All. 1b) provides the 10% probability of exceedance in 50 years of the horizontal acceleration at rock sites (i.e., Vs30>800 m/s; cat. A, 3.2.1 of the D.M. 14.09.2005).

The colours indicate the various values of the ground acceleration that have 10% to be exceeded within 50 years. In general, the colours associated to low values of acceleration refer to areas that are less hazardous and stronger earthquakes repeat less frequently although they may still occur.

Seismic hazard map

Seismic hazard map

This map shows the seismic hazard map of Italy for the region where the earthquake occurred.
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 earthquake resentment in the area, expressed in terms of intensity on the MCS scale (Mercalli-Cancani-Sieberg). Intensities are determined using data from questionnaires collected on the website http://www.hsit.it. The intensities shown are determined considering all the reports received from each municipality, and are all the more reliable the greater the number of questionnaires. The collected data are subjected to an automatic statistical filter, but are not checked individually. In particular, intensities greater than or equal to the VI degree of the MCS or EMS scale require on-site verification by specialized personnel. The black star is the epicenter of the earthquake that occurred. This map is updated every time citizens fill out new questionnaires. The number of questionnaires processed to obtain this map, the date and time of the last update are shown at the top right.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Bulletin
Rev1000
ML 0.8 2021-12-27
16:23:12
44.223 8.2487 10 2022-03-30
13:04:32
Bollettino Sismico Italiano INGV 99985361
Reviewed
Rev100
ML 2.4 2021-12-27
16:23:12
44.2052 8.2797 9 2021-12-27
16:36:24
Sala Sismica INGV-Roma 99061691
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-12-27 16:23:12 ± 0.16
Latitude 44.2230 ± 0.0144
Longitude 8.2487 ± 0.0213
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 99985361

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 2250
Semi-minor axis of confidence ellipse (meter) 660
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 132
Circular confidence region, given by single value of horizontal uncertainty (meter) 2250.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 173
Number of associated phases, regardless of their use for origin computation 35
Number of defining phases 18
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.36
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.93170
Number of stations at which the event was observed 24
Number of stations from which data was used for origin computation 11
Magnitudes information

ML:2.4

Field Value
Value 2.4
Uncertainty 0.2
Num. used stations 4
Type of magnitude ML
Reference to an origin 99061691
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-12-27 16:36:24

ML:0.8

Field Value
Value 0.8
Uncertainty 0.3
Num. used stations 7
Type of magnitude ML
Reference to an origin 99985361
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2022-02-01 11:10:50
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.RMP.HHZ. 2021-12-27T16:27:15.40 3.0 undecidable manual S 9.999 0
IV.PP3.EHZ. 2021-12-27T16:27:00.70 3.0 undecidable manual S 9.999 0
IX.STN3.HNZ.01 2021-12-27T16:25:06.04 3.0 undecidable manual P 1.602 0
IV.FREG.EHZ. 2021-12-27T16:25:06.86 3.0 undecidable manual Sg 15.15 0
CR.STON.BHZ. 2021-12-27T16:25:03.38 3.0 undecidable manual P 8.08 0
IV.VITU.HHZ. 2021-12-27T16:24:52.34 3.0 undecidable manual P 1.626 0
IV.GATE.HHZ. 2021-12-27T16:24:52.30 3.0 positive manual P 1.628 0
OT.OT17.EHZ. 2021-12-27T16:24:42.68 3.0 negative manual P 3.74 0
IV.BRSN.EHZ. 2021-12-27T16:24:39.60 3.0 undecidable manual S 1.006 0
IV.PTRJ.HHZ. 2021-12-27T16:24:36.52 3.0 undecidable manual P 2.72 0
IV.RMP.HHZ. 2021-12-27T16:24:27.75 3.0 positive manual P 1.286 0
IV.ZEN8.EHZ. 2021-12-27T16:24:23.20 3.0 undecidable manual S 5.14 0
IV.PP3.EHZ. 2021-12-27T16:24:15.48 3.0 negative manual P 1.85 0
IV.CAPR.HNZ. 2021-12-27T16:24:14.04 3.0 undecidable manual Sg 1.11 0
IV.ARVD.HHZ. 2021-12-27T16:24:10.42 3.0 positive manual P 3.69 0
IV.BRSN.EHZ. 2021-12-27T16:23:59.92 3.0 negative manual P 3.04 0
IV.ZEN8.EHZ. 2021-12-27T16:23:56.77 3.0 negative manual P 6.52 0
GU.BHB.HNZ. 2021-12-27T16:23:30.47 0.3 undecidable manual P 311 0.9317 50 0.6 56
GU.PZZ.HHE. 2021-12-27T16:23:29.27 0.3 undecidable manual P 290 0.8580 50 0.66 56
GU.STV.HHZ. 2021-12-27T16:23:26.30 1.0 undecidable manual P 272 0.6610 50 1.06 16
GU.PCP.HHZ. 2021-12-27T16:23:26.10 1.0 undecidable manual S 34 0.3822 50 -0.35 23
GU.IMI.HHZ. 2021-12-27T16:23:26.90 1.0 undecidable manual S 219 0.4029 50 -0.17 23
GU.ENR.HHZ. 2021-12-27T16:23:25.06 1.0 undecidable manual P 271 0.5945 50 0.95 17
GU.MGRO.HHZ. 2021-12-27T16:23:25.10 1.0 undecidable manual S 240 0.3633 50 -0.8 20
GU.GBOS.HHZ. 2021-12-27T16:23:22.66 0.6 undecidable manual S 274 0.2932 50 -1.15 34
GU.MGRO.HHZ. 2021-12-27T16:23:20.14 0.1 undecidable manual P 240 0.3633 50 -0.02 97
GU.PCP.HHZ. 2021-12-27T16:23:20.26 0.1 undecidable manual P 34 0.3822 50 -0.21 93
GU.IMI.HHZ. 2021-12-27T16:23:20.99 0.1 undecidable manual P 219 0.4029 50 0.15 94
GU.RORO.HHZ. 2021-12-27T16:23:19.00 0.6 undecidable manual S 230 0.1709 117 -0.67 43
GU.GBOS.HHZ. 2021-12-27T16:23:18.78 0.1 undecidable manual P 274 0.2932 50 -0.17 96
IV.QLNO.HHZ. 2021-12-27T16:23:17.63 0.3 undecidable manual S 35 0.1232 125 -0.45 70
GU.RORO.HHZ. 2021-12-27T16:23:16.64 0.1 undecidable manual P 230 0.1709 117 0.08 100
IV.QLNO.HHZ. 2021-12-27T16:23:15.76 0.1 undecidable manual P 35 0.1232 125 0.12 100
GU.CANO.HHZ. 2021-12-27T16:23:15.60 0.3 undecidable manual S 208 0.0171 168 -0.07 77
GU.CANO.HHZ. 2021-12-27T16:23:14.57 0.1 undecidable manual P 208 0.0171 168 0.32 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
GU.CANO.HHE. ML:0.0 0.00044771355 0.1536 AML other m 2021-12-27T16:23:15.62
GU.CANO.HHN. ML:0.0 0.0003340278 0.0768 AML other m 2021-12-27T16:23:15.64
IV.ZEN8.EHE. ML:0.0 0.000022700000000000003 0.62 AML other m 2021-12-27T16:24:27.63
IV.ZEN8.EHN. ML:0.0 0.000044 0.94 AML other m 2021-12-27T16:24:28.64
IV.QLNO.HHE. ML:0.8 0.00006132782000000001 0.2176 AML other m 2021-12-27T16:23:17.76
IV.QLNO.HHN. ML:1.1 0.0001379935 0.1152 AML other m 2021-12-27T16:23:17.79
GU.RORO.HHN. ML:1.2 0.00013562345000000002 0.128 AML other m 2021-12-27T16:23:19.15
GU.GBOS.HHE. ML:0.7 0.000019782959999999997 0.1536 AML other m 2021-12-27T16:23:22.85
GU.GBOS.HHN. ML:0.5 0.000015049570000000002 0.128 AML other m 2021-12-27T16:23:22.92
GU.ENR.HHN. ML:0.9 0.0000151051505 0.128 AML other m 2021-12-27T16:23:33.64
GU.ENR.HHE. ML:0.7 0.000010235701 0.1408 AML other m 2021-12-27T16:23:33.66
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Fault Plane solutions

Fault Plane solutions

The map reports the fault plane solutions for earthquakes in the region from 1977 to the date of this event. Red moment tensors are determined using the Regional Centroid Moment Tensor technique (RCMT, http://www.bo.ingv.it/RCMT) applied for earthquakes with magnitude larger than 4.5 in the Euro-Mediterranenan area. Occasionally, when a station azimuthal coverage exists RCMTs can be obtained also for earthquakes with magnitude down to 4.0. The gray moment tensors are obtained with the Time Domain Moment Tensor method (TDMT, http://terremoti.ingv.it/tdmt). This technique is applied to earthquakes with magnitude ML greater than 3.2, when it is possible. The size of symbols scales with the calculated moment magnitude Mw.
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download
Waveforms Seismic signals in miniseed + resp format Download