Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.5 on date 18-09-2023 and time 19:54:16 (UTC) in region 4 km E Marradi (FI)

A magnitude ML 0.5 earthquake occured in region: 4 km E Marradi (FI), on

  • 18-09-2023 19:54:16 (UTC)
  • 18-09-2023 21:54:16 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0700, 11.6590 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
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 17 2617 17314
Brisighella RA 19 7639 24953
Dovadola FC 19 1653 26606

Municipalities with at least 50000 inhabitants

An earthquake occurred to
30 Km SW of Faenza (58541 inhabitants)
32 Km S of Imola (69797 inhabitants)
35 Km W of Forlì (117913 inhabitants)
46 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)
54 Km SE of Bologna (386663 inhabitants)
58 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)
85 Km S of Ferrara (133155 inhabitants)
87 Km SE of Modena (184973 inhabitants)
88 Km NE of Siena (53903 inhabitants)
96 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 0.5 2023-09-18
19:54:16		 44.0698 11.6593 6 2023-09-18
19:59:57		 Sala Sismica INGV-Roma 121205441
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-18 19:54:16 ± 0.09
Latitude 44.0698 ± 0.0027
Longitude 11.6593 ± 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 121205441

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 310
Semi-minor axis of confidence ellipse (meter) 90
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 319
Circular confidence region, given by single value of horizontal uncertainty (meter) 310.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 90
Number of associated phases, regardless of their use for origin computation 22
Number of defining phases 21
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) 0.39750
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 11
Magnitude information

ML:0.5

Field Value
Value 0.5
Uncertainty 0.3
Num. used stations 12
Type of magnitude ML
Reference to an origin 121205441
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-18 19:59:57
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.BRSN.EHE. 2023-09-18T19:54:31.25 3.0 undecidable manual S -0.01 0
IV.FNVD.HHN. 2023-09-18T19:54:26.12 1.0 undecidable manual P 284 44.1225 50 0.47 21
IV.RUFI.EHZ. 2023-09-18T19:54:26.68 0.3 undecidable manual S 205 28.3494 101 -0.12 71
IV.BOSL.HHZ. 2023-09-18T19:54:26.52 0.1 undecidable manual S 236 27.4503 102 0.03 96
IV.SEI.HHZ. 2023-09-18T19:54:25.29 0.3 undecidable manual S 266 24.0537 103 -0.05 72
IV.SFI.EHZ. 2023-09-18T19:54:25.20 0.3 undecidable manual S 141 23.6541 104 0 73
IV.RINC.EHZ. 2023-09-18T19:54:24.55 0.3 undecidable manual S 192 20.7681 106 0.31 69
IV.VISG.HHZ. 2023-09-18T19:54:24.80 0.3 undecidable manual S 307 22.2555 105 0.06 72
IV.VMGN.HHZ. 2023-09-18T19:54:23.07 0.3 undecidable manual S 218 16.2726 109 0.31 69
IV.BOSL.HHZ. 2023-09-18T19:54:22.37 0.1 undecidable manual P 236 27.4503 102 -0.01 96
IT.MOG.HNZ. 2023-09-18T19:54:22.38 0.3 undecidable manual S 37 14.0748 112 0.35 69
IV.RUFI.EHZ. 2023-09-18T19:54:22.16 0.6 positive manual P 205 28.3494 101 -0.4 44
IV.RINC.EHZ. 2023-09-18T19:54:21.02 1.0 negative manual P 192 20.7681 106 -0.05 24
IV.SFI.EHZ. 2023-09-18T19:54:21.39 0.6 positive manual P 141 23.6541 104 -0.24 46
IV.VISG.HHZ. 2023-09-18T19:54:21.13 0.3 undecidable manual P 307 22.2555 105 -0.23 70
IV.SEI.HHZ. 2023-09-18T19:54:21.40 0.6 positive manual P 266 24.0537 103 -0.31 46
IV.VMGN.HHZ. 2023-09-18T19:54:20.31 0.6 positive manual P 218 16.2726 109 0.09 48
IV.LMD.HHZ. 2023-09-18T19:54:19.05 0.3 undecidable manual S 77 3.8961 146 -0.13 73
IT.MRR.HGZ. 2023-09-18T19:54:19.33 0.3 undecidable manual S 262 4.4955 142 0.03 75
IT.MOG.HNZ. 2023-09-18T19:54:19.85 0.1 undecidable manual P 37 14.0748 112 0.05 98
IT.MRR.HGZ. 2023-09-18T19:54:18.24 0.1 undecidable manual P 262 4.4955 142 0.02 100
IV.LMD.HHZ. 2023-09-18T19:54:17.92 0.6 undecidable manual P 77 3.8961 146 -0.23 48
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:0.0 0.00019735289999999999 0.1408 AML other m 2023-09-18T19:54:19.05
IV.LMD.HHN. ML:0.0 0.0005257604499999999 0.1408 AML other m 2023-09-18T19:54:19.11
IV.VMGN.HHE. ML:0.2 0.000016491785000000003 0.1792 AML other m 2023-09-18T19:54:23.40
IV.VMGN.HHN. ML:0.2 0.00001701068 0.2048 AML other m 2023-09-18T19:54:23.44
IV.RINC.EHE. ML:0.4 0.00001894483 0.1408 AML other m 2023-09-18T19:54:24.64
IV.RINC.EHN. ML:0.4 0.0000201861535 1.088 AML other m 2023-09-18T19:54:32.52
IV.SFI.HNE. ML:1.3 0.00012361621 0.8192 AML other m 2023-09-18T19:54:31.90
IV.SFI.HNN. ML:1.2 0.00011000896000000001 0.704 AML other m 2023-09-18T19:54:25.21
IV.SFI.EHE. ML:0.4 0.00001579577 0.2048 AML other m 2023-09-18T19:54:25.29
IV.SFI.EHN. ML:0.4 0.000017095832999999997 0.2048 AML other m 2023-09-18T19:54:25.93
IV.SEI.HHE. ML:0.9 0.000052229945 0.512 AML other m 2023-09-18T19:54:22.73
IV.SEI.HHN. ML:1.0 0.000059368395000000005 0.2432 AML other m 2023-09-18T19:54:25.73
IV.RUFI.EHE. ML:0.4 0.000012936025 0.4352 AML other m 2023-09-18T19:54:26.00
IV.RUFI.EHN. ML:0.3 0.000011908889999999998 1.344 AML other m 2023-09-18T19:54:35.08
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