Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 20-09-2023 and time 07:29:41 (UTC) in region 4 km E Marradi (FI)

A magnitude ML 1.1 earthquake occured in region: 4 km E Marradi (FI), on

  • 20-09-2023 07:29:41 (UTC)
  • 20-09-2023 09:29:41 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0780, 11.6580 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 4 3139 3139
Tredozio FC 7 1212 4351
Palazzuolo sul Senio FI 10 1154 5505
Portico e San Benedetto FC 11 756 6261
Modigliana FC 14 4560 10821
Premilcuore FC 15 799 11620
Rocca San Casciano FC 15 1910 13530
Casola Valsenio RA 17 2617 16147
San Godenzo FI 17 1167 17314
Brisighella RA 18 7639 24953
Dovadola FC 19 1653 26606
Castel del Rio BO 19 1246 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
29 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)
47 Km W of Cesena (96758 inhabitants)
50 Km E of Prato (191150 inhabitants)
52 Km NE of Scandicci (50609 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
57 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
70 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
84 Km S of Ferrara (133155 inhabitants)
86 Km SE of Modena (184973 inhabitants)
88 Km NE of Siena (53903 inhabitants)
96 Km E of Lucca (89046 inhabitants)
100 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 1.1 2023-09-20
07:29:41		 44.0785 11.6582 6 2023-09-20
07:40:57		 Sala Sismica INGV-Roma 121264271
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-20 07:29:41 ± 0.08
Latitude 44.0785 ± 0.0036
Longitude 11.6582 ± 0.0050
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 121264271

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 356
Semi-minor axis of confidence ellipse (meter) 135
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) 360.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 75
Number of associated phases, regardless of their use for origin computation 24
Number of defining phases 24
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) 0.03507
Epicentral distance of station farthest from the epicenter (degree) 0.50542
Number of stations at which the event was observed 13
Number of stations from which data was used for origin computation 13
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 16
Type of magnitude ML
Reference to an origin 121264271
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-20 07:40:57
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CRE.HHZ. 2023-09-20T07:30:00.22 0.6 undecidable manual S 155 56.0994 50 -0.01 46
IV.MOCL.EHZ. 2023-09-20T07:29:55.16 0.6 undecidable manual S 258 38.9277 99 -0.28 45
IV.RUFI.EHZ. 2023-09-20T07:29:52.09 0.6 undecidable manual S 204 29.2485 102 -0.04 48
IV.CRE.HHZ. 2023-09-20T07:29:51.93 0.6 undecidable manual P 155 56.0994 50 -0.49 42
IV.SEI.HHZ. 2023-09-20T07:29:50.46 0.6 undecidable manual S 264 24.0537 105 0.08 48
IV.SFI.EHZ. 2023-09-20T07:29:50.70 0.6 undecidable manual S 142 24.4533 105 0.17 47
IV.RINC.EHZ. 2023-09-20T07:29:50.12 0.6 undecidable manual S 191 21.6672 107 0.51 44
IV.VISG.HHZ. 2023-09-20T07:29:49.76 0.6 undecidable manual S 305 21.6672 107 0.18 47
IV.MOCL.EHZ. 2023-09-20T07:29:49.19 1.0 undecidable manual P 258 38.9277 99 -0.47 22
IV.VMGN.HHZ. 2023-09-20T07:29:48.52 0.6 undecidable manual S 216 16.9719 111 0.46 45
IV.MTRZ.HNE. 2023-09-20T07:29:48.64 0.1 undecidable manual P 325 31.9458 101 0.36 89
IT.MOG.HNE. 2023-09-20T07:29:47.17 0.6 undecidable manual S 40 13.3755 116 0.27 47
IV.RUFI.EHZ. 2023-09-20T07:29:47.53 0.1 undecidable manual P 204 29.2485 102 -0.22 93
IV.SFI.EHZ. 2023-09-20T07:29:47.03 0.6 negative manual P 142 24.4533 105 0.21 47
IV.BOSL.HHN. 2023-09-20T07:29:47.49 0.1 undecidable manual P 234 27.9498 103 -0.01 97
IV.RINC.EHZ. 2023-09-20T07:29:46.40 0.6 negative manual P 191 21.6672 107 0.11 48
IV.SEI.HHZ. 2023-09-20T07:29:46.57 0.1 negative manual P 264 24.0537 105 -0.17 94
IV.VISG.HHZ. 2023-09-20T07:29:46.12 0.3 negative manual P 305 21.6672 107 -0.15 71
IV.VMGN.HHZ. 2023-09-20T07:29:45.63 0.6 positive manual P 216 16.9719 111 0.23 47
IT.MRR.HGZ. 2023-09-20T07:29:44.39 0.6 undecidable manual S 250 4.6953 144 -0.12 49
IT.MOG.HNE. 2023-09-20T07:29:44.80 0.1 undecidable manual P 40 13.3755 116 0.08 98
IV.LMD.HHZ. 2023-09-20T07:29:43.98 0.6 undecidable manual S 92 3.8961 149 -0.39 47
IT.MRR.HGZ. 2023-09-20T07:29:43.30 0.1 undecidable manual P 250 4.6953 144 -0.04 100
IV.LMD.HHZ. 2023-09-20T07:29:43.05 0.1 undecidable manual P 92 3.8961 149 -0.21 97
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHE. ML:0.7 0.000048952415 0.1408 AML other m 2023-09-20T07:29:49.16
IV.VISG.HHE. ML:0.8 0.00004265 0.16 AML other m 2023-09-20T07:29:49.86
IV.VISG.HHN. ML:0.9 0.00006234333999999999 0.1024 AML other m 2023-09-20T07:29:50.13
IV.SEI.HHE. ML:1.7 0.0003305 0.22 AML other m 2023-09-20T07:29:50.86
IV.SEI.HHN. ML:2.0 0.000684 0.22 AML other m 2023-09-20T07:29:50.99
IV.VMGN.HHN. ML:0.9 0.00006755 0.28 AML other m 2023-09-20T07:29:51.05
IV.RINC.EHE. ML:1.0 0.0000785733 0.1152 AML other m 2023-09-20T07:29:50.14
IV.RINC.EHN. ML:1.0 0.000067521505 0.4032 AML other m 2023-09-20T07:29:54.80
IV.MOCL.EHN. ML:1.5 0.00011499999999999999 0.14 AML other m 2023-09-20T07:29:55.59
IV.MOCL.EHE. ML:1.2 0.00006464151 0.1216 AML other m 2023-09-20T07:29:56.19
IV.SFI.EHE. ML:1.0 0.000058580325 0.0832 AML other m 2023-09-20T07:29:51.46
IV.SFI.EHN. ML:1.0 0.00006935955499999999 0.0768 AML other m 2023-09-20T07:29:51.41
IV.SFI.HNE. ML:1.1 0.0000869359 0.6912 AML other m 2023-09-20T07:29:47.64
IV.SFI.HNN. ML:1.2 0.0000947578 0.5312 AML other m 2023-09-20T07:29:55.59
IV.CRE.HHE. ML:1.0 0.000025587235 0.1792 AML other m 2023-09-20T07:30:00.79
IV.CRE.HHN. ML:1.6 0.00007768677 0.1792 AML other m 2023-09-20T07:30:00.64
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