Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.2 on date 21-09-2023 and time 21:42:17 (UTC) in region 3 km E Marradi (FI)

A magnitude ML 1.2 earthquake occured in region: 3 km E Marradi (FI), on

  • 21-09-2023 21:42:17 (UTC)
  • 21-09-2023 23:42:17 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0680, 11.6520 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 10 1154 5505
Portico e San Benedetto FC 11 756 6261
Premilcuore FC 14 799 7060
Modigliana FC 15 4560 11620
Rocca San Casciano FC 15 1910 13530
San Godenzo FI 16 1167 14697
Casola Valsenio RA 18 2617 17314
Brisighella RA 20 7639 24953
Dovadola FC 20 1653 26606
Castel del Rio BO 20 1246 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
31 Km SW of Faenza (58541 inhabitants)
32 Km S of Imola (69797 inhabitants)
36 Km W of Forlì (117913 inhabitants)
46 Km NE of Firenze (382808 inhabitants)
48 Km W of Cesena (96758 inhabitants)
49 Km E of Prato (191150 inhabitants)
51 Km NE of Scandicci (50609 inhabitants)
54 Km SE of Bologna (386663 inhabitants)
59 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
69 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
86 Km S of Ferrara (133155 inhabitants)
86 Km SE of Modena (184973 inhabitants)
87 Km NE of Siena (53903 inhabitants)
95 Km E of Lucca (89046 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 1.2 2023-09-21
21:42:17		 44.0685 11.6522 6 2023-09-21
21:47:19		 Sala Sismica INGV-Roma 121325201
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-21 21:42:17 ± 0.11
Latitude 44.0685 ± 0.0027
Longitude 11.6522 ± 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 121325201

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 350
Semi-minor axis of confidence ellipse (meter) 110
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 150
Circular confidence region, given by single value of horizontal uncertainty (meter) 350.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 91
Number of associated phases, regardless of their use for origin computation 25
Number of defining phases 22
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.17
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.34444
Number of stations at which the event was observed 14
Number of stations from which data was used for origin computation 11
Magnitude information

ML:1.2

Field Value
Value 1.2
Uncertainty 0.2
Num. used stations 12
Type of magnitude ML
Reference to an origin 121325201
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-21 21:47:19
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.ARCI.HHZ. 2023-09-21T21:42:57.41 3.0 undecidable manual S -0.27 0
IV.MOCL.EHZ. 2023-09-21T21:42:30.87 0.6 undecidable manual S 260 38.2284 99 -0.2 46
IV.ZCCA.HNZ. 2023-09-21T21:42:28.20 3.0 undecidable manual P -0.33 0
IV.RUFI.EHZ. 2023-09-21T21:42:27.43 0.6 undecidable manual S 204 27.9498 102 -0.13 48
IV.BOSL.HHZ. 2023-09-21T21:42:26.96 0.6 undecidable manual S 236 26.9508 103 -0.24 47
IV.SEI.HHZ. 2023-09-21T21:42:26.22 0.6 undecidable manual S 266 23.4543 104 0.19 47
IV.SFI.EHZ. 2023-09-21T21:42:26.18 0.6 undecidable manual S 139 23.8539 104 0 49
IV.RINC.EHZ. 2023-09-21T21:42:25.33 0.6 undecidable manual S 190 20.4684 106 0.28 47
IV.IMOL.EHZ. 2023-09-21T21:42:25.09 3.0 negative manual P 1.99 0
IV.VISG.HHZ. 2023-09-21T21:42:25.60 0.6 undecidable manual S 308 21.867 105 0.09 48
IV.MOCL.EHZ. 2023-09-21T21:42:24.95 0.6 undecidable manual P 260 38.2284 99 -0.43 44
IV.RUFI.EHZ. 2023-09-21T21:42:23.12 1.0 undecidable manual P 204 27.9498 102 -0.25 23
IV.BOSL.HHZ. 2023-09-21T21:42:23.16 0.6 positive manual P 236 26.9508 103 0 49
IT.MOG.HNE. 2023-09-21T21:42:23.41 0.6 undecidable manual S 39 14.5743 113 0.32 47
IV.VMGN.HHZ. 2023-09-21T21:42:23.97 0.6 undecidable manual S 217 15.873 111 0.46 45
IV.SEI.HHZ. 2023-09-21T21:42:22.37 0.1 positive manual P 266 23.4543 104 -0.11 96
IV.SFI.EHZ. 2023-09-21T21:42:22.37 0.6 positive manual P 139 23.8539 104 -0.2 47
IV.VISG.HHZ. 2023-09-21T21:42:22.14 1.0 positive manual P 308 21.867 105 -0.04 24
IV.VMGN.HHZ. 2023-09-21T21:42:21.29 0.3 positive manual P 217 15.873 111 0.27 71
IV.RINC.EHZ. 2023-09-21T21:42:21.98 0.6 undecidable manual P 190 20.4684 106 0.07 49
IT.MRR.HGZ. 2023-09-21T21:42:20.12 0.6 undecidable manual S 263 3.8961 147 -0.01 51
IT.MOG.HNE. 2023-09-21T21:42:20.92 0.1 undecidable manual P 39 14.5743 113 0.14 97
IT.MRR.HGZ. 2023-09-21T21:42:19.16 0.1 undecidable manual P 263 3.8961 147 0.09 100
IV.LMD.HHZ. 2023-09-21T21:42:19.90 0.6 undecidable manual S 77 4.4955 143 -0.34 47
IV.LMD.HHZ. 2023-09-21T21:42:18.99 0.1 undecidable manual P 77 4.4955 143 -0.14 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHN. ML:1.2 0.00016749999999999998 0.38 AML other m 2023-09-21T21:42:24.52
IV.VMGN.HHE. ML:1.2 0.000151 0.18 AML other m 2023-09-21T21:42:24.52
IV.SEI.HHE. ML:1.4 0.000165 0.6 AML other m 2023-09-21T21:42:26.06
IV.SFI.EHN. ML:1.2 0.00011005 0.36 AML other m 2023-09-21T21:42:26.61
IV.VISG.HHN. ML:1.1 0.0001013 1.36 AML other m 2023-09-21T21:42:26.05
IV.SFI.EHE. ML:1.3 0.0001235 1.18 AML other m 2023-09-21T21:42:26.85
IV.VISG.HHE. ML:1.0 0.00006544999999999999 1.58 AML other m 2023-09-21T21:42:26.11
IV.BOSL.HHN. ML:0.8 0.000036150000000000005 1.58 AML other m 2023-09-21T21:42:27.02
IV.BOSL.HHE. ML:0.6 0.0000264 0.78 AML other m 2023-09-21T21:42:28.97
IV.SEI.HHN. ML:1.6 0.0002395 0.5 AML other m 2023-09-21T21:42:29.98
IV.MOCL.EHN. ML:1.4 0.00009665 0.38 AML other m 2023-09-21T21:42:31.20
IV.MOCL.EHE. ML:1.3 0.0000687 1.4 AML other m 2023-09-21T21:42:31.08
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