Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 18-09-2023 and time 05:42:22 (UTC) in region 6 km SE Marradi (FI)

A magnitude ML 1.1 earthquake occured in region: 6 km SE Marradi (FI), on

  • 18-09-2023 05:42:22 (UTC)
  • 18-09-2023 07:42:22 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0420, 11.6690 at 11 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 6 3139 3139
Tredozio FC 7 1212 4351
Portico e San Benedetto FC 9 756 5107
Premilcuore FC 11 799 5906
Palazzuolo sul Senio FI 13 1154 7060
San Godenzo FI 13 1167 8227
Rocca San Casciano FC 14 1910 10137
Modigliana FC 16 4560 14697
Dovadola FC 20 1653 16350

Municipalities with at least 50000 inhabitants

An earthquake occurred to
32 Km SW of Faenza (58541 inhabitants)
35 Km S of Imola (69797 inhabitants)
36 Km SW of Forlì (117913 inhabitants)
45 Km NE of Firenze (382808 inhabitants)
47 Km W of Cesena (96758 inhabitants)
49 Km E of Prato (191150 inhabitants)
50 Km NE of Scandicci (50609 inhabitants)
57 Km SE of Bologna (386663 inhabitants)
60 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
66 Km N of Arezzo (99543 inhabitants)
72 Km W of Rimini (147750 inhabitants)
85 Km NE of Siena (53903 inhabitants)
89 Km S of Ferrara (133155 inhabitants)
90 Km SE of Modena (184973 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 1.1 2023-09-18
05:42:22		 44.0417 11.6693 11 2023-09-18
05:47:34		 Sala Sismica INGV-Roma 121162351
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-18 05:42:22 ± 0.13
Latitude 44.0417 ± 0.0045
Longitude 11.6693 ± 0.0063
Depth (km) 11 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121162351

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 643
Semi-minor axis of confidence ellipse (meter) 335
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 221
Circular confidence region, given by single value of horizontal uncertainty (meter) 640.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 186
Number of associated phases, regardless of their use for origin computation 12
Number of defining phases 12
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.16
Epicentral distance of station closest to the epicenter (degree) 0.13130
Epicentral distance of station farthest from the epicenter (degree) 0.23382
Number of stations at which the event was observed 6
Number of stations from which data was used for origin computation 6
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 6
Type of magnitude ML
Reference to an origin 121162351
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-18 05:47:34
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SEI.HHZ. 2023-09-18T05:42:31.16 0.1 undecidable manual S 273 24.8529 50 -0.06 98
IV.VISG.HHZ. 2023-09-18T05:42:31.46 0.1 undecidable manual S 311 24.8529 50 0.23 94
IV.RUFI.EHZ. 2023-09-18T05:42:31.57 0.1 undecidable manual S 210 25.9518 50 0.05 98
IV.SFI.EHZ. 2023-09-18T05:42:30.21 0.1 undecidable manual S 137 20.7681 50 0.07 98
IV.RINC.EHZ. 2023-09-18T05:42:29.27 0.1 undecidable manual S 196 17.9709 121 -0.01 100
IV.VMGN.HHZ. 2023-09-18T05:42:28.28 0.1 undecidable manual S 228 14.5743 126 -0.03 100
IV.SEI.HHZ. 2023-09-18T05:42:27.09 0.6 undecidable manual P 273 24.8529 50 -0.25 47
IV.VISG.HHZ. 2023-09-18T05:42:27.09 0.6 undecidable manual P 311 24.8529 50 -0.25 47
IV.RUFI.EHZ. 2023-09-18T05:42:27.40 0.6 negative manual P 210 25.9518 50 -0.12 48
IV.RINC.EHZ. 2023-09-18T05:42:26.57 0.6 undecidable manual P 196 17.9709 121 0.35 46
IV.SFI.EHZ. 2023-09-18T05:42:26.46 0.6 undecidable manual P 137 20.7681 50 -0.25 47
IV.VMGN.HHZ. 2023-09-18T05:42:25.65 0.6 positive manual P 228 14.5743 126 -0.01 50
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHN. ML:1.2 0.000163 0.16 AML other m 2023-09-18T05:42:28.64
IV.VMGN.HHE. ML:1.1 0.000122 0.36 AML other m 2023-09-18T05:42:28.52
IV.SFI.EHE. ML:0.9 0.0000558 1.76 AML other m 2023-09-18T05:42:29.96
IV.SFI.EHN. ML:0.8 0.00003985 0.96 AML other m 2023-09-18T05:42:30.19
IV.SEI.HHE. ML:1.1 0.00006839999999999998 0.68 AML other m 2023-09-18T05:42:31.38
IV.SEI.HHN. ML:1.4 0.0001325 0.16 AML other m 2023-09-18T05:42:31.46
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