Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.4 on date 20-09-2023 and time 07:26:25 (UTC) in region 4 km E Marradi (FI)

A magnitude ML 1.4 earthquake occured in region: 4 km E Marradi (FI), on

  • 20-09-2023 07:26:25 (UTC)
  • 20-09-2023 09:26:25 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0810, 11.6670 at 8 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 6 1212 4351
Palazzuolo sul Senio FI 10 1154 5505
Portico e San Benedetto FC 11 756 6261
Modigliana FC 13 4560 10821
Rocca San Casciano FC 14 1910 12731
Premilcuore FC 15 799 13530
Casola Valsenio RA 16 2617 16147
San Godenzo FI 18 1167 17314
Brisighella RA 18 7639 24953
Dovadola FC 18 1653 26606
Castel del Rio BO 20 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)
34 Km W of Forlì (117913 inhabitants)
46 Km W of Cesena (96758 inhabitants)
48 Km NE of Firenze (382808 inhabitants)
51 Km E of Prato (191150 inhabitants)
53 Km NE of Scandicci (50609 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
57 Km SW of Ravenna (159116 inhabitants)
62 Km E of Pistoia (90315 inhabitants)
70 Km N of Arezzo (99543 inhabitants)
72 Km W of Rimini (147750 inhabitants)
84 Km S of Ferrara (133155 inhabitants)
86 Km SE of Modena (184973 inhabitants)
89 Km NE of Siena (53903 inhabitants)
97 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 1.4 2023-09-20
07:26:25		 44.081 11.6668 8 2023-09-20
07:35:22		 Sala Sismica INGV-Roma 121264031
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-20 07:26:25 ± 0.1
Latitude 44.0810 ± 0.0045
Longitude 11.6668 ± 0.0063
Depth (km) 8 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121264031

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 467
Semi-minor axis of confidence ellipse (meter) 379
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 120
Circular confidence region, given by single value of horizontal uncertainty (meter) 470.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 96
Number of associated phases, regardless of their use for origin computation 19
Number of defining phases 19
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.24
Epicentral distance of station closest to the epicenter (degree) 0.02968
Epicentral distance of station farthest from the epicenter (degree) 0.50542
Number of stations at which the event was observed 10
Number of stations from which data was used for origin computation 10
Magnitude information

ML:1.4

Field Value
Value 1.4
Uncertainty 0.3
Num. used stations 12
Type of magnitude ML
Reference to an origin 121264031
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-20 07:35:22
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CRE.HHZ. 2023-09-20T07:26:43.86 0.6 undecidable manual S 156 56.0994 50 0.23 45
IV.MOCL.EHZ. 2023-09-20T07:26:39.04 0.6 undecidable manual S 258 39.627 50 -0.21 46
IV.CRE.HHZ. 2023-09-20T07:26:35.84 0.3 negative manual P 156 56.0994 50 -0.11 69
IV.RINC.EHZ. 2023-09-20T07:26:34.01 0.6 undecidable manual S 193 22.0668 109 0.42 46
IV.SEI.HHZ. 2023-09-20T07:26:34.52 0.6 undecidable manual S 263 24.753 107 0.06 49
IV.VISG.HHZ. 2023-09-20T07:26:33.68 0.6 undecidable manual S 303 22.0668 109 0.11 49
IV.MOCL.EHZ. 2023-09-20T07:26:33.03 1.0 positive manual P 258 39.627 50 -0.39 22
IV.VMGN.HHZ. 2023-09-20T07:26:32.56 0.3 undecidable manual S 217 17.6712 114 0.41 69
IT.MOG.HNZ. 2023-09-20T07:26:31.06 0.6 undecidable manual S 39 12.6762 121 0.44 46
IV.RINC.EHZ. 2023-09-20T07:26:30.34 0.6 positive manual P 193 22.0668 109 0.19 48
IV.SFI.HNZ. 2023-09-20T07:26:30.09 0.1 undecidable manual P 144 24.2535 108 -0.47 90
IV.SEI.HHZ. 2023-09-20T07:26:30.53 0.1 negative manual P 263 24.753 107 -0.13 97
IV.VISG.HHZ. 2023-09-20T07:26:30.09 0.3 negative manual P 303 22.0668 109 -0.05 74
IV.VMGN.HHZ. 2023-09-20T07:26:29.62 0.6 undecidable manual P 217 17.6712 114 0.3 47
IT.MRR.HGZ. 2023-09-20T07:26:28.35 0.6 undecidable manual S 250 5.3946 145 -0.39 47
IT.MOG.HNZ. 2023-09-20T07:26:28.73 0.1 undecidable manual P 39 12.6762 121 0.29 95
IV.LMD.HHZ. 2023-09-20T07:26:27.02 1.0 undecidable manual P 97 3.2967 157 -0.12 25
IT.MRR.HGZ. 2023-09-20T07:26:27.23 0.1 undecidable manual P 250 5.3946 145 -0.12 100
IV.LMD.HHZ. 2023-09-20T07:26:27.98 0.6 undecidable manual S 97 3.2967 157 -0.39 47
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:0.0 0.0014608695 0.1184 AML other m 2023-09-20T07:26:28.23
IV.VMGN.HHE. ML:1.1 0.000103515235 0.2624 AML other m 2023-09-20T07:26:33.07
IV.VISG.HHN. ML:1.0 0.00007505007 0.1216 AML other m 2023-09-20T07:26:33.89
IV.VISG.HHE. ML:0.9 0.000055874975 0.1792 AML other m 2023-09-20T07:26:34.02
IV.RINC.EHN. ML:1.3 0.00014249825 0.48 AML other m 2023-09-20T07:26:34.64
IV.SEI.HHE. ML:1.8 0.0003569991 0.2016 AML other m 2023-09-20T07:26:34.72
IV.SEI.HHN. ML:2.1 0.0008803994500000001 0.2208 AML other m 2023-09-20T07:26:34.93
IV.VMGN.HHN. ML:1.2 0.00014227165 0.2784 AML other m 2023-09-20T07:26:35.01
IV.RINC.EHE. ML:1.3 0.00013679405 0.2208 AML other m 2023-09-20T07:26:34.08
IV.MOCL.EHN. ML:1.7 0.0001605 0.6 AML other m 2023-09-20T07:26:39.47
IV.MOCL.EHE. ML:1.4 0.00009470000000000001 0.3 AML other m 2023-09-20T07:26:40.34
IV.CRE.HHE. ML:1.6 0.00009054999999999999 0.24 AML other m 2023-09-20T07:26:44.76
IV.CRE.HHN. ML:1.8 0.000143 0.26 AML other m 2023-09-20T07:26:44.76
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