Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 18-09-2023 and time 06:53:56 (UTC) in region 1 km SW Marradi (FI)

A magnitude ML 1.0 earthquake occured in region: 1 km SW Marradi (FI), on

  • 18-09-2023 06:53:56 (UTC)
  • 18-09-2023 08:53:56 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0690, 11.6040 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 1 3139 3139
Palazzuolo sul Senio FI 7 1154 4293
Tredozio FC 11 1212 5505
Portico e San Benedetto FC 15 756 6261
San Godenzo FI 16 1167 7428
Premilcuore FC 17 799 8227
Casola Valsenio RA 17 2617 10844
Castel del Rio BO 18 1246 12090
Modigliana FC 18 4560 16650
Vicchio FI 19 8044 24694
Firenzuola FI 19 4726 29420
Rocca San Casciano FC 19 1910 31330

Municipalities with at least 50000 inhabitants

An earthquake occurred to
33 Km SW of Faenza (58541 inhabitants)
33 Km S of Imola (69797 inhabitants)
39 Km W of Forlì (117913 inhabitants)
43 Km NE of Firenze (382808 inhabitants)
46 Km E of Prato (191150 inhabitants)
48 Km NE of Scandicci (50609 inhabitants)
52 Km W of Cesena (96758 inhabitants)
52 Km SE of Bologna (386663 inhabitants)
57 Km E of Pistoia (90315 inhabitants)
61 Km SW of Ravenna (159116 inhabitants)
71 Km NW of Arezzo (99543 inhabitants)
77 Km W of Rimini (147750 inhabitants)
84 Km SE of Modena (184973 inhabitants)
85 Km S of Ferrara (133155 inhabitants)
86 Km N of Siena (53903 inhabitants)
92 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 1.0 2023-09-18
06:53:56		 44.0693 11.6045 11 2023-09-18
07:01:12		 Sala Sismica INGV-Roma 121167291
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-18 06:53:56 ± 0.1
Latitude 44.0693 ± 0.0054
Longitude 11.6045 ± 0.0100
Depth (km) 11 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121167291

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 840
Semi-minor axis of confidence ellipse (meter) 534
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 258
Circular confidence region, given by single value of horizontal uncertainty (meter) 840.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 179
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 13
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.22
Epicentral distance of station closest to the epicenter (degree) 0.12591
Epicentral distance of station farthest from the epicenter (degree) 0.51531
Number of stations at which the event was observed 7
Number of stations from which data was used for origin computation 7
Magnitude information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.3
Num. used stations 9
Type of magnitude ML
Reference to an origin 121167291
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-18 07:01:12
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CRE.HHZ. 2023-09-18T06:54:15.51 0.6 undecidable manual S 151 57.1983 50 0.9 36
IV.CRE.HHZ. 2023-09-18T06:54:07.19 0.6 undecidable manual P 151 57.1983 50 0.12 46
IV.SFI.EHZ. 2023-09-18T06:54:06.36 0.3 undecidable manual S 133 26.6511 50 -0.09 73
IV.RUFI.EHZ. 2023-09-18T06:54:06.35 0.3 undecidable manual S 196 26.751 50 -0.14 72
IV.VISG.HHZ. 2023-09-18T06:54:04.35 0.1 undecidable manual S 314 18.9699 119 0.03 100
IV.SEI.HHZ. 2023-09-18T06:54:04.79 0.6 undecidable manual S 265 19.6692 118 0.25 47
IV.VMGN.HHZ. 2023-09-18T06:54:02.79 0.3 undecidable manual S 204 13.9749 127 -0.08 75
IV.RUFI.EHZ. 2023-09-18T06:54:02.32 0.1 undecidable manual P 196 26.751 50 -0.07 97
IV.SFI.EHZ. 2023-09-18T06:54:02.18 0.1 undecidable manual P 133 26.6511 50 -0.18 95
IV.SEI.HHZ. 2023-09-18T06:54:01.01 0.6 undecidable manual P 265 19.6692 118 -0.25 48
IV.RINC.EHZ. 2023-09-18T06:54:01.31 0.1 undecidable manual P 179 20.2686 118 -0.06 99
IV.VISG.HHZ. 2023-09-18T06:54:01.14 0.1 undecidable manual P 314 18.9699 119 0.01 100
IV.VMGN.HHZ. 2023-09-18T06:54:00.40 0.1 undecidable manual P 204 13.9749 127 0.11 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHN. ML:0.8 0.000052699999999999993 1.34 AML other m 2023-09-18T06:54:02.19
IV.VMGN.HHE. ML:0.9 0.00007340000000000001 1.54 AML other m 2023-09-18T06:54:03.84
IV.VISG.HHN. ML:1.1 0.00009779999999999999 0.94 AML other m 2023-09-18T06:54:04.64
IV.VISG.HHE. ML:1.0 0.0000813 0.18 AML other m 2023-09-18T06:54:04.68
IV.SEI.HHN. ML:1.4 0.00019800000000000002 0.32 AML other m 2023-09-18T06:54:04.99
IV.SEI.HHE. ML:1.1 0.00009604999999999999 0.24 AML other m 2023-09-18T06:54:05.19
IV.SFI.EHN. ML:0.9 0.0000395 0.6 AML other m 2023-09-18T06:54:06.86
IV.SFI.EHE. ML:0.9 0.000039 1.84 AML other m 2023-09-18T06:54:07.04
IV.CRTC.HHE. ML:2.1 0.00010350000000000001 0.84 AML other m 2023-09-18T06:54:22.79
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