Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.7 on date 31-12-2021 and time 10:29:24 (Italy) in region 8 km NW Chiaramonte Gulfi (RG)

A magnitude ML 1.7 earthquake occured in region: 8 km NW Chiaramonte Gulfi (RG), on

  • 31-12-2021 09:29:24 (UTC)
  • 31-12-2021 10:29:24 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 37.0910, 14.6530 at 19 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.

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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
Chiaramonte Gulfi RG 8 8238 8238
Mazzarrone CT 8 4078 12316
Licodia Eubea CT 9 3081 15397
Monterosso Almo RG 10 3032 18429
Vizzini CT 12 6241 24670
Giarratana RG 13 3048 27718
Grammichele CT 14 13418 41136
Acate RG 16 10954 52090
Comiso RG 17 30156 82246
Buccheri SR 18 1999 84245
Vittoria RG 19 63339 147584
Ragusa RG 20 73313 220897
Mineo CT 20 5159 226056

Municipalities with at least 50000 inhabitants

An earthquake occurred to
19 Km NE of Vittoria (63339 inhabitants)
20 Km NW of Ragusa (73313 inhabitants)
28 Km NW of Modica (54633 inhabitants)
36 Km E of Gela (75827 inhabitants)
57 Km W of Siracusa (122291 inhabitants)
60 Km SW of Catania (314555 inhabitants)
69 Km SE of Caltanissetta (63360 inhabitants)
74 Km SW of Acireale (52622 inhabitants)
98 Km E of Agrigento (59770 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 1.7 2021-12-31
09:29:24		 37.0912 14.6527 19 2022-03-30
13:04:31		 Bollettino Sismico Italiano INGV 99884711
Reviewed
Rev100 		ML 1.7 2021-12-31
09:29:24		 37.093 14.6458 20 2021-12-31
09:39:06		 Sala Sismica INGV-Roma 99188741
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-12-31 09:29:24 ± 0.19
Latitude 37.0912 ± 0.0072
Longitude 14.6527 ± 0.0090
Depth (km) 19 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 99884711

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 931
Semi-minor axis of confidence ellipse (meter) 228
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 130
Circular confidence region, given by single value of horizontal uncertainty (meter) 930.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 73
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 17
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.29
Epicentral distance of station closest to the epicenter (degree) 0.10072
Epicentral distance of station farthest from the epicenter (degree) 0.62323
Number of stations at which the event was observed 10
Number of stations from which data was used for origin computation 10
Magnitudes information

ML:1.7

Field Value
Value 1.7
Uncertainty 0.1
Num. used stations 16
Type of magnitude ML
Reference to an origin 99188741
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-12-31 09:39:06

ML:1.7

Field Value
Value 1.7
Uncertainty 0.1
Num. used stations 14
Type of magnitude ML
Reference to an origin 99884711
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2022-01-17 16:30:47
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.GALF.HHZ. 2021-12-31T09:29:37.37 1.0 undecidable manual P 354 69.1752 98 0.34 22
IV.SSY.HHZ. 2021-12-31T09:29:37.77 1.0 undecidable manual S 79 37.9287 107 -0.02 24
IV.RAFF.HHZ. 2021-12-31T09:29:36.44 0.3 undecidable manual S 300 29.5482 113 0.77 59
IV.CROCE.HHZ. 2021-12-31T09:29:36.14 0.3 undecidable manual S 200 30.5472 113 0.22 72
IV.HLNI.HHZ. 2021-12-31T09:29:36.77 0.3 undecidable manual S 34 34.5432 109 -0.14 73
IV.HAGA.HHE. 2021-12-31T09:29:34.29 0.6 undecidable manual P 64 49.3173 102 0.27 46
IV.HMDC.HHZ. 2021-12-31T09:29:33.47 0.3 undecidable manual S 142 18.6702 128 0.3 73
IV.ISPIC.EHZ. 2021-12-31T09:29:32.84 0.3 undecidable manual P 147 41.0256 106 0.06 73
IV.SSY.HHZ. 2021-12-31T09:29:32.68 0.6 negative manual P 79 37.9287 107 0.35 46
IV.HVZN.HHZ. 2021-12-31T09:29:32.06 0.3 undecidable manual S 30 11.1777 145 0.28 73
IV.HVIT.HHZ. 2021-12-31T09:29:32.29 0.3 undecidable manual S 227 15.9729 133 -0.33 72
IV.CROCE.HHZ. 2021-12-31T09:29:31.13 0.3 undecidable manual P 200 30.5472 113 -0.12 73
IV.HLNI.HHZ. 2021-12-31T09:29:31.40 0.1 undecidable manual P 34 34.5432 109 -0.42 91
IV.RAFF.HHZ. 2021-12-31T09:29:30.90 0.1 undecidable manual P 300 29.5482 113 -0.2 97
IV.HMDC.HHZ. 2021-12-31T09:29:29.83 0.1 undecidable manual P 142 18.6702 128 0.17 99
IV.HVZN.HHZ. 2021-12-31T09:29:28.68 0.1 positive manual P 30 11.1777 145 -0.18 100
IV.HVIT.HHZ. 2021-12-31T09:29:28.92 0.1 positive manual P 227 15.9729 133 -0.42 94
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.HVZN.HHE. ML:1.7 0.00035450000000000005 0.14 AML other m 2021-12-31T09:29:32.18
IV.HVZN.HHN. ML:1.7 0.0003895 0.68 AML other m 2021-12-31T09:29:32.16
IV.HVIT.HHN. ML:1.8 0.000381 0.24 AML other m 2021-12-31T09:29:32.80
IV.HVIT.HHE. ML:1.7 0.0003305 0.5 AML other m 2021-12-31T09:29:33.36
IV.HMDC.HNE. ML:1.6 0.000248671185 1.808 AML other m 2021-12-31T09:29:33.05
IV.HMDC.HHN. ML:1.8 0.000338 1.64 AML other m 2021-12-31T09:29:34.13
IV.HMDC.HNN. ML:1.6 0.00024216444999999997 1.648 AML other m 2021-12-31T09:29:34.96
IV.HMDC.HHE. ML:1.8 0.00040149999999999995 1.56 AML other m 2021-12-31T09:29:34.04
IV.RAFF.HHE. ML:1.7 0.000199 0.42 AML other m 2021-12-31T09:29:35.61
IV.CROCE.HHE. ML:1.5 0.000122401055 0.2624 AML other m 2021-12-31T09:29:36.37
IV.CROCE.HNN. ML:1.7 0.00021880865 0.4672 AML other m 2021-12-31T09:29:36.44
IV.CROCE.HHN. ML:1.7 0.0001955 0.58 AML other m 2021-12-31T09:29:36.45
IV.CROCE.HNE. ML:1.6 0.000150413085 0.1024 AML other m 2021-12-31T09:29:36.42
IV.RAFF.HHN. ML:1.7 0.00020649999999999998 0.38 AML other m 2021-12-31T09:29:36.59
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