Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.4 on date 20-09-2023 and time 18:21:24 (UTC) in region 3 km E Marradi (FI)

A magnitude ML 1.4 earthquake occured in region: 3 km E Marradi (FI), on

  • 20-09-2023 18:21:24 (UTC)
  • 20-09-2023 20:21:24 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0800, 11.6490 at 6 km depth.

The earthquake was located by: Sala Sismica INGV-Roma.

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
Marradi FI 3 3139 3139
Tredozio FC 8 1212 4351
Palazzuolo sul Senio FI 9 1154 5505
Portico e San Benedetto FC 12 756 6261
Modigliana FC 14 4560 10821
Premilcuore FC 15 799 11620
Rocca San Casciano FC 16 1910 13530
Casola Valsenio RA 16 2617 16147
San Godenzo FI 17 1167 17314
Brisighella RA 19 7639 24953
Castel del Rio BO 19 1246 26199
Dovadola FC 20 1653 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
30 Km SW of Faenza (58541 inhabitants)
31 Km S of Imola (69797 inhabitants)
35 Km W of Forlì (117913 inhabitants)
47 Km NE of Firenze (382808 inhabitants)
48 Km W of Cesena (96758 inhabitants)
49 Km E of Prato (191150 inhabitants)
52 Km NE of Scandicci (50609 inhabitants)
52 Km SE of Bologna (386663 inhabitants)
58 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
71 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
84 Km S of Ferrara (133155 inhabitants)
85 Km SE of Modena (184973 inhabitants)
88 Km NE of Siena (53903 inhabitants)
95 Km E of Lucca (89046 inhabitants)
99 Km SE of Carpi (70699 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
Reviewed
Rev100 		ML 1.4 2023-09-20
18:21:24		 44.0798 11.6492 6 2023-09-20
18:30:15		 Sala Sismica INGV-Roma 121285801
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-20 18:21:24 ± 0.08
Latitude 44.0798 ± 0.0027
Longitude 11.6492 ± 0.0038
Depth (km) 6 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121285801

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 320
Semi-minor axis of confidence ellipse (meter) 88
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 134
Circular confidence region, given by single value of horizontal uncertainty (meter) 320.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 50
Number of associated phases, regardless of their use for origin computation 26
Number of defining phases 25
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.50992
Number of stations at which the event was observed 15
Number of stations from which data was used for origin computation 14
Magnitude information

ML:1.4

Field Value
Value 1.4
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 121285801
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-20 18:30:15
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.FOSV.EHZ. 2023-09-20T18:22:01.32 3.0 undecidable manual S -0.01 0
IV.CRE.HHZ. 2023-09-20T18:21:42.75 0.6 undecidable manual S 155 56.5989 50 -0.14 45
IV.MOCL.EHZ. 2023-09-20T18:21:37.39 0.6 undecidable manual S 258 38.2284 99 -0.28 45
IV.CRE.HHZ. 2023-09-20T18:21:34.45 1.0 undecidable manual P 155 56.5989 50 -0.55 20
IV.RUFI.EHZ. 2023-09-20T18:21:34.57 0.3 undecidable manual S 203 29.0487 102 0.04 72
IV.SFI.EHZ. 2023-09-20T18:21:33.30 0.6 undecidable manual S 141 25.0527 104 0.13 47
IV.RINC.EHZ. 2023-09-20T18:21:32.43 0.6 undecidable manual S 189 21.7671 106 0.38 45
IV.SEI.HHZ. 2023-09-20T18:21:32.62 0.6 undecidable manual S 263 23.3544 105 0.02 49
IV.VISG.HHZ. 2023-09-20T18:21:31.93 0.3 undecidable manual S 305 20.9679 106 0.13 71
IV.IMOL.HNZ. 2023-09-20T18:21:31.37 1.0 undecidable manual P 13 31.9458 101 0.63 21
IV.MOCL.EHZ. 2023-09-20T18:21:31.53 0.6 undecidable manual P 258 38.2284 99 -0.46 43
IV.MTRZ.HNZ. 2023-09-20T18:21:30.91 0.1 undecidable manual P 325 31.4463 101 0.27 91
IV.VMGN.HHZ. 2023-09-20T18:21:30.96 0.6 undecidable manual S 214 16.7721 110 0.56 43
IV.SFI.EHZ. 2023-09-20T18:21:29.28 0.6 positive manual P 141 25.0527 104 -0.11 48
IT.MOG.HNZ. 2023-09-20T18:21:29.49 0.3 undecidable manual S 43 13.7751 114 0.05 74
IV.BOSL.HHZ. 2023-09-20T18:21:29.89 0.6 positive manual P 233 27.4503 103 0.03 48
IV.RUFI.EHZ. 2023-09-20T18:21:29.93 0.1 undecidable manual P 203 29.0487 102 -0.25 92
IV.RINC.EHZ. 2023-09-20T18:21:28.86 0.3 positive manual P 189 21.7671 106 0.11 72
IV.SEI.HHZ. 2023-09-20T18:21:28.91 0.1 undecidable manual P 263 23.3544 105 -0.15 95
IV.VISG.HHZ. 2023-09-20T18:21:28.46 0.1 undecidable manual P 305 20.9679 106 -0.14 95
IV.VMGN.HHZ. 2023-09-20T18:21:28.07 0.1 positive manual P 214 16.7721 110 0.28 93
IT.MOG.HNZ. 2023-09-20T18:21:27.34 0.1 undecidable manual P 43 13.7751 114 0.11 97
IT.MRR.HGZ. 2023-09-20T18:21:26.59 0.3 undecidable manual S 244 4.0959 146 -0.17 73
IV.LMD.HHZ. 2023-09-20T18:21:26.71 0.3 undecidable manual S 93 4.5954 143 -0.17 73
IT.MRR.HGZ. 2023-09-20T18:21:25.66 0.1 undecidable manual P 244 4.0959 146 -0.04 100
IV.LMD.HHZ. 2023-09-20T18:21:25.60 0.1 undecidable manual P 93 4.5954 143 -0.16 97
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHE. ML:1.1 0.00012615 0.48 AML other m 2023-09-20T18:21:31.53
IV.SFI.EHE. ML:1.4 0.00016199999999999998 0.48 AML other m 2023-09-20T18:21:33.48
IV.VMGN.HHN. ML:1.2 0.00014850000000000003 0.44 AML other m 2023-09-20T18:21:33.50
IV.RINC.EHE. ML:1.5 0.0002465 1.24 AML other m 2023-09-20T18:21:33.26
IV.SFI.EHN. ML:1.7 0.0002925 0.1 AML other m 2023-09-20T18:21:34.05
IV.BOSL.HHN. ML:1.0 0.000059550000000000004 1.72 AML other m 2023-09-20T18:21:34.90
IV.BOSL.HHE. ML:1.0 0.0000544 1.3 AML other m 2023-09-20T18:21:34.27
IV.RINC.EHN. ML:1.4 0.000189 0.34 AML other m 2023-09-20T18:21:36.33
IV.CRE.HHN. ML:1.9 0.00019250000000000002 0.2 AML other m 2023-09-20T18:21:43.18
IV.CRE.HHE. ML:1.6 0.00007875 0.24 AML other m 2023-09-20T18:21:43.42
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