Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 2.1 on date 21-03-2021 and time 10:42:24 (Italy) in region 1 km E Sant'Alfio (CT)

A magnitude ML 2.1 earthquake occured in region: 1 km E Sant'Alfio (CT), on

  • 21-03-2021 09:42:24 (UTC)
  • 21-03-2021 10:42:24 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 37.7440, 15.1540 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
Sant'Alfio CT 1 1582 1582
Giarre CT 3 27659 29241
Milo CT 4 1087 30328
Mascali CT 4 14282 44610
Riposto CT 5 14838 59448
Santa Venerina CT 6 8592 68040
Zafferana Etnea CT 7 9517 77557
Fiumefreddo di Sicilia CT 7 9623 87180
Piedimonte Etneo CT 8 3963 91143
Linguaglossa CT 11 5403 96546
Calatabiano CT 11 5308 101854
Gaggi ME 14 3184 105038
Acireale CT 15 52622 157660
Giardini-Naxos ME 15 9415 167075
Aci Sant'Antonio CT 15 17984 185059
Trecastagni CT 16 10910 195969
Viagrande CT 16 8563 204532
Aci Catena CT 16 29851 234383
Castiglione di Sicilia CT 16 3215 237598
Pedara CT 16 14102 251700
Aci Bonaccorsi CT 17 3524 255224
Taormina ME 17 10960 266184
Castelmola ME 17 1088 267272
Motta Camastra ME 17 845 268117
Francavilla di Sicilia ME 18 3945 272062
Graniti ME 18 1492 273554
Nicolosi CT 18 7463 281017
Valverde CT 18 7840 288857
San Giovanni la Punta CT 19 23060 311917
Moio Alcantara ME 20 717 312634
Tremestieri Etneo CT 20 20589 333223

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km N of Acireale (52622 inhabitants)
27 Km N of Catania (314555 inhabitants)
59 Km SW of Reggio di Calabria (183035 inhabitants)
61 Km SW of Messina (238439 inhabitants)
77 Km N of Siracusa (122291 inhabitants)
98 Km NE of Ragusa (73313 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 2.1 2021-03-21
09:42:24		 37.7442 15.154 10 2021-07-12
16:55:05		 Bollettino Sismico Italiano INGV 88766321
Reviewed
Rev200 		ML 1.6 2021-03-21
09:42:24		 37.761 15.125 10 2021-06-23
10:26:04		 Sala Operativa INGV-OE (Catania) 88342591
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-03-21 09:42:24 ± 0.12
Latitude 37.7442 ± 0.0063
Longitude 15.1540 ± 0.0080
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 88766321

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 724
Semi-minor axis of confidence ellipse (meter) 686
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 279
Circular confidence region, given by single value of horizontal uncertainty (meter) 720.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 115
Number of associated phases, regardless of their use for origin computation 25
Number of defining phases 24
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) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.43167
Number of stations at which the event was observed 16
Number of stations from which data was used for origin computation 15
Magnitudes information

ML:2.1

Field Value
Value 2.1
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 88766321
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-06-23 10:25:49

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations
Type of magnitude ML
Reference to an origin 88342591
Agency INGV
Autore Sala Operativa INGV-OE (Catania)
Time of creation (UTC) 2021-03-21 09:46:01
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SELL.HHZ. 2021-03-21T09:42:51.67 3.0 positive manual Pg -0.07 0
IV.MPNC.HHZ. 2021-03-21T09:42:33.40 0.3 undecidable manual P 21 47.9187 50 0.44 64
IV.AIO.HHZ. 2021-03-21T09:42:33.93 0.6 undecidable manual S 15 26.1516 50 0.25 46
IV.NOV.HHZ. 2021-03-21T09:42:30.28 0.3 undecidable manual P 357 31.5462 50 -0.15 70
IV.EPZF.HHZ. 2021-03-21T09:42:30.11 0.3 undecidable manual P 289 27.5502 50 0.3 68
IV.EPIT.HHZ. 2021-03-21T09:42:29.98 0.3 undecidable manual S 311 11.3775 132 0.7 62
IV.EMCN.HHZ. 2021-03-21T09:42:29.73 0.3 undecidable manual S 296 11.7771 130 0.33 70
IV.AIO.HHZ. 2021-03-21T09:42:29.37 0.1 undecidable manual P 15 26.1516 50 -0.23 93
IV.ESPC.HHZ. 2021-03-21T09:42:29.58 0.6 undecidable manual S 243 12.4764 129 -0.01 50
IV.EFIU.HHZ. 2021-03-21T09:42:28.64 0.3 undecidable manual S 44 7.0929 145 0.36 70
IV.ECBD.HHZ. 2021-03-21T09:42:28.29 0.3 undecidable manual S 304 7.1928 145 -0.01 75
IV.EVRN.HHZ. 2021-03-21T09:42:28.66 0.3 undecidable manual S 195 6.2937 148 0.52 67
IV.ECTS.HHZ. 2021-03-21T09:42:27.30 0.3 undecidable manual P 349 15.5733 123 -0.44 68
IV.EPIT.HHZ. 2021-03-21T09:42:27.09 0.1 undecidable manual P 311 11.3775 132 0.03 99
IV.EMFS.HHZ. 2021-03-21T09:42:27.37 0.1 undecidable manual P 259 13.9749 126 -0.1 97
IV.ESAL.HHZ. 2021-03-21T09:42:27.44 0.3 undecidable manual S 306 2.0979 168 -0.14 74
IV.EPOZ.HHZ. 2021-03-21T09:42:27.11 0.1 undecidable manual P 159 8.5803 140 0.44 91
IV.EMFO.HHZ. 2021-03-21T09:42:27.91 0.3 undecidable manual S 261 5.6943 151 -0.12 74
IV.EMCN.HHZ. 2021-03-21T09:42:27.21 0.1 undecidable manual P 296 11.7771 130 0.09 98
IV.EVRN.HHZ. 2021-03-21T09:42:26.37 0.1 undecidable manual P 195 6.2937 148 -0.03 100
IV.ESPC.HHZ. 2021-03-21T09:42:26.95 0.1 undecidable manual P 243 12.4764 129 -0.29 94
IV.EMFO.HHZ. 2021-03-21T09:42:26.04 0.1 undecidable manual P 261 5.6943 151 -0.3 95
IV.EFIU.HHZ. 2021-03-21T09:42:26.24 0.1 undecidable manual P 44 7.0929 145 -0.25 96
IV.ECBD.HHZ. 2021-03-21T09:42:26.24 0.1 undecidable manual P 304 7.1928 145 -0.26 95
IV.ESAL.HHZ. 2021-03-21T09:42:25.63 0.1 undecidable manual P 306 2.0979 168 -0.45 92
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ESAL.HHN. ML:2.4 0.0049866015 0.2048 AML other m 2021-03-21T09:42:27.83
IV.ESAL.HHE. ML:2.4 0.0052183005 0.1984 AML other m 2021-03-21T09:42:27.96
IV.EVRN.HHE. ML:2.3 0.0028 0.22 AML other m 2021-03-21T09:42:28.90
IV.EVRN.HNE. ML:2.2 0.002755 0.26 AML other m 2021-03-21T09:42:28.91
IV.EFIU.HHN. ML:1.7 0.0007776425999999999 0.4032 AML other m 2021-03-21T09:42:29.18
IV.EFIU.HHE. ML:1.6 0.00069397365 0.3392 AML other m 2021-03-21T09:42:29.78
IV.EVRN.HNN. ML:2.4 0.003716621 0.4352 AML other m 2021-03-21T09:42:32.34
IV.EVRN.HHN. ML:2.3 0.0029485045 0.4224 AML other m 2021-03-21T09:42:32.33
IV.EPOZ.HHN. ML:1.7 0.0006969849500000001 0.3008 AML other m 2021-03-21T09:42:34.30
IV.EPOZ.HHE. ML:1.8 0.0008440451 0.224 AML other m 2021-03-21T09:42:32.42
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