Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.9 on date 18-09-2023 and time 06:41:04 (UTC) in region 2 km E Marradi (FI)

A magnitude ML 0.9 earthquake occured in region: 2 km E Marradi (FI), on

  • 18-09-2023 06:41:04 (UTC)
  • 18-09-2023 08:41:04 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0820, 11.6370 at 10 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 2 3139 3139
Palazzuolo sul Senio FI 8 1154 4293
Tredozio FC 9 1212 5505
Portico e San Benedetto FC 13 756 6261
Modigliana FC 15 4560 10821
Casola Valsenio RA 16 2617 13438
Premilcuore FC 16 799 14237
Rocca San Casciano FC 17 1910 16147
San Godenzo FI 17 1167 17314
Castel del Rio BO 18 1246 18560
Brisighella RA 19 7639 26199

Municipalities with at least 50000 inhabitants

An earthquake occurred to
30 Km SW of Faenza (58541 inhabitants)
31 Km S of Imola (69797 inhabitants)
36 Km W of Forlì (117913 inhabitants)
46 Km NE of Firenze (382808 inhabitants)
49 Km E of Prato (191150 inhabitants)
49 Km W of Cesena (96758 inhabitants)
51 Km NE of Scandicci (50609 inhabitants)
52 Km SE of Bologna (386663 inhabitants)
58 Km SW of Ravenna (159116 inhabitants)
60 Km E of Pistoia (90315 inhabitants)
71 Km N of Arezzo (99543 inhabitants)
74 Km W of Rimini (147750 inhabitants)
84 Km S of Ferrara (133155 inhabitants)
85 Km SE of Modena (184973 inhabitants)
88 Km N of Siena (53903 inhabitants)
95 Km E of Lucca (89046 inhabitants)
98 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 0.9 2023-09-18
06:41:04		 44.0815 11.6373 10 2023-09-18
06:52:02		 Sala Sismica INGV-Roma 121166701
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-18 06:41:04 ± 0.09
Latitude 44.0815 ± 0.0036
Longitude 11.6373 ± 0.0075
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121166701

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 582
Semi-minor axis of confidence ellipse (meter) 451
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 267
Circular confidence region, given by single value of horizontal uncertainty (meter) 580.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 193
Number of associated phases, regardless of their use for origin computation 11
Number of defining phases 11
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.14
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.25990
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:0.9

Field Value
Value 0.9
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 121166701
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-18 06:52:02
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.GSCL.HHZ. 2023-09-18T06:41:30.56 0.6 undecidable manual S 0 1
IV.RUFI.EHZ. 2023-09-18T06:41:14.78 0.3 undecidable manual S 201 28.8489 50 0.13 72
IV.SFI.EHZ. 2023-09-18T06:41:13.96 0.3 undecidable manual S 139 25.752 50 0.14 73
IV.VISG.HHZ. 2023-09-18T06:41:12.36 0.3 undecidable manual S 306 20.0688 117 0.19 73
IV.SEI.HHZ. 2023-09-18T06:41:12.79 0.3 undecidable manual S 262 22.4553 115 -0.12 73
IV.VMGN.HHZ. 2023-09-18T06:41:11.04 0.3 undecidable manual S 211 16.3725 122 -0.02 76
IV.RUFI.EHZ. 2023-09-18T06:41:10.19 0.1 undecidable manual P 201 28.8489 50 -0.1 97
IV.SEI.HHZ. 2023-09-18T06:41:09.20 0.1 undecidable manual P 262 22.4553 115 -0.08 99
IV.SFI.EHZ. 2023-09-18T06:41:09.58 0.3 undecidable manual P 139 25.752 50 -0.23 71
IV.VISG.HHZ. 2023-09-18T06:41:08.83 0.1 undecidable manual P 306 20.0688 117 -0.03 100
IV.VMGN.HHZ. 2023-09-18T06:41:08.34 0.1 undecidable manual P 211 16.3725 122 0.13 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHE. ML:0.8 0.0000514 0.42 AML other m 2023-09-18T06:41:11.57
IV.VISG.HHN. ML:0.9 0.00005555 0.48 AML other m 2023-09-18T06:41:12.47
IV.VISG.HHE. ML:0.6 0.000030449999999999998 0.6 AML other m 2023-09-18T06:41:12.49
IV.SEI.HHE. ML:1.3 0.00012734999999999998 1.78 AML other m 2023-09-18T06:41:13.92
IV.SEI.HHN. ML:1.5 0.0002055 0.22 AML other m 2023-09-18T06:41:13.33
IV.VMGN.HHN. ML:0.7 0.000042749999999999996 0.68 AML other m 2023-09-18T06:41:13.50
IV.SFI.EHN. ML:0.9 0.000043450000000000006 0.34 AML other m 2023-09-18T06:41:14.65
IV.SFI.EHE. ML:0.8 0.0000335 0.74 AML other m 2023-09-18T06:41:15.50
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