Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.8 on date 23-07-2021 and time 18:24:31 (Italy) in region 2 km W Bronte (CT)

A magnitude ML 1.8 earthquake occured in region: 2 km W Bronte (CT), on

  • 23-07-2021 16:24:31 (UTC)
  • 23-07-2021 18:24:31 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 37.7830, 14.8070 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.

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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
Bronte CT 2 19172 19172
Maletto CT 7 3920 23092
Maniace CT 9 3765 26857
Cesarò ME 11 2439 29296
San Teodoro ME 12 1403 30699
Adrano CT 14 36122 66821
Randazzo CT 16 10900 77721
Biancavilla CT 17 24007 101728
Troina EN 18 9373 111101
Centuripe EN 19 5470 116571
Santa Maria di Licodia CT 20 7641 124212

Municipalities with at least 50000 inhabitants

An earthquake occurred to
37 Km NW of Acireale (52622 inhabitants)
40 Km NW of Catania (314555 inhabitants)
73 Km E of Caltanissetta (63360 inhabitants)
80 Km SW of Messina (238439 inhabitants)
82 Km W of Reggio di Calabria (183035 inhabitants)
91 Km NW of Siracusa (122291 inhabitants)
94 Km NE of Gela (75827 inhabitants)
96 Km N of Ragusa (73313 inhabitants)
96 Km N of Vittoria (63339 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 1.8 2021-07-23
16:24:31		 37.7833 14.8072 10 2021-12-29
11:12:51		 Bollettino Sismico Italiano INGV 97364531
Reviewed
Rev200 		ML 1.5 2021-07-23
16:24:30		 37.766 14.779 10 2021-11-09
15:17:05		 Sala Operativa INGV_OE (Catania) 93112961
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-07-23 16:24:31 ± 0.14
Latitude 37.7833 ± 0.0108
Longitude 14.8072 ± 0.0091
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 97364531

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1132
Semi-minor axis of confidence ellipse (meter) 761
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 164
Circular confidence region, given by single value of horizontal uncertainty (meter) 1130.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 101
Number of associated phases, regardless of their use for origin computation 23
Number of defining phases 23
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.38
Epicentral distance of station closest to the epicenter (degree) 0.03687
Epicentral distance of station farthest from the epicenter (degree) 0.34174
Number of stations at which the event was observed 14
Number of stations from which data was used for origin computation 14
Magnitudes information

ML:1.8

Field Value
Value 1.8
Uncertainty 0.2
Num. used stations 14
Type of magnitude ML
Reference to an origin 97364531
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-11-09 15:16:52

ML:1.5

Field Value
Value 1.5
Uncertainty 0.2
Num. used stations
Type of magnitude ML
Reference to an origin 93112961
Agency INGV
Autore Sala Operativa INGV_OE (Catania)
Time of creation (UTC) 2021-07-23 16:36:21
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MCPD.HHE. 2021-07-23T16:24:44.74 0.6 undecidable manual S 350 37.9287 50 -0.09 47
IV.MUCR.HHZ. 2021-07-23T16:24:42.30 0.6 undecidable manual S 11 29.3484 50 -0.24 46
IV.GALF.HHZ. 2021-07-23T16:24:41.22 0.3 undecidable manual S 249 22.5552 113 0.71 61
IV.MCPD.HHE. 2021-07-23T16:24:40.23 0.3 undecidable manual P 350 37.9287 50 0.84 56
IV.ESLN.HHZ. 2021-07-23T16:24:39.82 0.6 undecidable manual S 124 17.7711 119 0.83 39
IV.ESVO.HHE. 2021-07-23T16:24:38.08 0.6 undecidable manual S 95 12.2766 129 0.66 42
IV.MUCR.HHZ. 2021-07-23T16:24:37.70 0.3 undecidable manual P 11 29.3484 50 -0.37 67
IV.ECZM.HHN. 2021-07-23T16:24:37.17 0.6 undecidable manual S 124 10.2786 134 0.28 47
IV.EMSG.HHZ. 2021-07-23T16:24:37.84 0.6 undecidable manual S 72 13.1757 127 0.18 48
IV.EPIT.HHZ. 2021-07-23T16:24:36.87 0.3 undecidable manual P 82 22.0668 114 0.07 73
IV.ESLN.HHZ. 2021-07-23T16:24:36.37 0.3 undecidable manual P 124 17.7711 119 0.35 69
IV.EMNR.HHZ. 2021-07-23T16:24:36.30 0.1 undecidable manual P 79 19.5693 117 -0.04 98
IV.EMPL.HHZ. 2021-07-23T16:24:36.62 0.3 undecidable manual P 129 18.3705 118 0.48 67
IV.EPZF.HHZ. 2021-07-23T16:24:36.84 0.6 undecidable manual S 44 6.2937 147 0.84 40
IV.GALF.HHZ. 2021-07-23T16:24:36.85 0.1 undecidable manual P 249 22.5552 113 -0.05 97
IV.ESCV.HHZ. 2021-07-23T16:24:35.12 0.3 undecidable manual S 170 4.0959 157 -0.53 68
IV.EMFS.HHE. 2021-07-23T16:24:35.97 0.3 undecidable manual P 113 18.1707 118 -0.13 72
IV.ECHR.HHE. 2021-07-23T16:24:35.09 0.3 undecidable manual P 139 14.1747 125 -0.33 70
IV.EPZF.HHZ. 2021-07-23T16:24:34.24 0.1 negative manual P 44 6.2937 147 -0.05 100
IV.ECZM.HHN. 2021-07-23T16:24:34.41 0.1 undecidable manual P 124 10.2786 134 -0.4 92
IV.EMSG.HHZ. 2021-07-23T16:24:34.96 0.1 undecidable manual P 72 13.1757 127 -0.29 94
IV.ESVO.HHE. 2021-07-23T16:24:34.81 0.1 undecidable manual P 95 12.2766 129 -0.3 94
IV.ESCV.HHZ. 2021-07-23T16:24:33.44 0.1 undecidable manual P 170 4.0959 157 -0.65 86
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ESCV.HHE. ML:2.3 0.0033799999999999998 0.2 AML other m 2021-07-23T16:24:35.23
IV.ESCV.HHN. ML:2.3 0.00373 0.14 AML other m 2021-07-23T16:24:35.83
IV.EPZF.HHE. ML:1.9 0.001375 0.34 AML other m 2021-07-23T16:24:37.04
IV.EPZF.HHN. ML:2.0 0.0017 0.56 AML other m 2021-07-23T16:24:37.36
IV.GALF.HHN. ML:1.9 0.000506 1.02 AML other m 2021-07-23T16:24:41.34
IV.EMSG.HHE. ML:1.8 0.000643 0.24 AML other m 2021-07-23T16:24:42.06
IV.EMSG.HHN. ML:1.7 0.0005585 0.98 AML other m 2021-07-23T16:24:42.60
IV.EMPL.HHE. ML:1.8 0.0005715 0.9 AML other m 2021-07-23T16:24:42.84
IV.EPIT.HHE. ML:1.6 0.00029549999999999997 0.22 AML other m 2021-07-23T16:24:43.43
IV.MUCR.HHE. ML:1.4 0.00013000000000000002 1.22 AML other m 2021-07-23T16:24:43.07
IV.GALF.HHE. ML:1.8 0.0004555 0.66 AML other m 2021-07-23T16:24:43.49
IV.MUCR.HHN. ML:1.3 0.00008925 1.6 AML other m 2021-07-23T16:24:43.05
IV.EPIT.HHN. ML:1.8 0.00039 1.66 AML other m 2021-07-23T16:24:44.10
IV.EMPL.HHN. ML:1.9 0.000741 0.22 AML other m 2021-07-23T16:24:48.91
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