Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.6 on date 21-09-2023 and time 18:03:45 (UTC) in region 3 km E Marradi (FI)

A magnitude ML 0.6 earthquake occured in region: 3 km E Marradi (FI), on

  • 21-09-2023 18:03:45 (UTC)
  • 21-09-2023 20:03:45 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0760, 11.6520 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 3 3139 3139
Tredozio FC 7 1212 4351
Palazzuolo sul Senio FI 9 1154 5505
Portico e San Benedetto FC 12 756 6261
Modigliana FC 15 4560 10821
Premilcuore FC 15 799 11620
Rocca San Casciano FC 15 1910 13530
Casola Valsenio RA 17 2617 16147
San Godenzo FI 17 1167 17314
Brisighella RA 19 7639 24953
Castel del Rio BO 19 1246 26199
Dovadola FC 20 1653 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
30 Km SW of Faenza (58541 inhabitants)
31 Km S of Imola (69797 inhabitants)
35 Km W of Forlì (117913 inhabitants)
46 Km NE of Firenze (382808 inhabitants)
48 Km W of Cesena (96758 inhabitants)
49 Km E of Prato (191150 inhabitants)
52 Km NE of Scandicci (50609 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
58 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
70 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
85 Km S of Ferrara (133155 inhabitants)
86 Km SE of Modena (184973 inhabitants)
88 Km NE of Siena (53903 inhabitants)
96 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 0.6 2023-09-21
18:03:45		 44.0757 11.6523 6 2023-09-21
18:26:23		 Sala Sismica INGV-Roma 121320711
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-21 18:03:45 ± 0.09
Latitude 44.0757 ± 0.0036
Longitude 11.6523 ± 0.0025
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 121320711

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 285
Semi-minor axis of confidence ellipse (meter) 224
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 189
Circular confidence region, given by single value of horizontal uncertainty (meter) 290.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 141
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.11
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.24641
Number of stations at which the event was observed 9
Number of stations from which data was used for origin computation 8
Magnitude information

ML:0.6

Field Value
Value 0.6
Uncertainty 0.3
Num. used stations 4
Type of magnitude ML
Reference to an origin 121320711
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-21 18:26:23
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.ZCCA.HNZ. 2023-09-21T18:04:06.09 3.0 undecidable manual S 0.01 0
IV.BOSL.HHZ. 2023-09-21T18:03:55.21 0.3 undecidable manual S 234 27.3504 101 -0.05 71
IV.SFI.EHZ. 2023-09-21T18:03:54.40 0.3 undecidable manual S 141 24.5532 103 0.11 71
IV.VISG.HHZ. 2023-09-21T18:03:53.51 0.6 undecidable manual S 306 21.4674 104 0.26 46
IV.SEI.HHZ. 2023-09-21T18:03:53.99 0.6 undecidable manual S 264 23.5542 103 0.03 48
IV.VMGN.HHZ. 2023-09-21T18:03:51.85 0.6 undecidable manual S 215 16.4724 109 0.25 47
IV.SEI.HHZ. 2023-09-21T18:03:50.20 0.6 negative manual P 264 23.5542 103 -0.21 46
IV.BOSL.HHZ. 2023-09-21T18:03:50.95 0.6 undecidable manual P 234 27.3504 101 -0.22 46
IV.SFI.EHZ. 2023-09-21T18:03:50.45 0.6 positive manual P 141 24.5532 103 -0.16 47
IV.VMGN.HHZ. 2023-09-21T18:03:49.11 0.1 undecidable manual P 215 16.4724 109 0.06 97
IV.VISG.HHZ. 2023-09-21T18:03:49.99 1.0 undecidable manual P 306 21.4674 104 -0.01 24
IV.RINC.EHZ. 2023-09-21T18:03:49.97 0.6 undecidable manual P 190 21.2676 105 -0.01 48
IV.LMD.HHZ. 2023-09-21T18:03:48.01 0.3 undecidable manual S 87 4.3956 142 -0.01 75
IT.MRR.HGZ. 2023-09-21T18:03:47.87 0.3 undecidable manual S 252 4.0959 143 -0.09 74
IV.LMD.HHZ. 2023-09-21T18:03:47.00 1.0 undecidable manual P 87 4.3956 142 0.02 25
IT.MRR.HGZ. 2023-09-21T18:03:46.95 0.1 undecidable manual P 252 4.0959 143 0 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:0.0 0.0000619445 0.1024 AML other m 2023-09-21T18:03:48.15
IV.LMD.HHN. ML:0.0 0.00011707565 0.1024 AML other m 2023-09-21T18:03:48.13
IV.VISG.HHE. ML:0.3 0.000014254275 0.1664 AML other m 2023-09-21T18:03:53.62
IV.VISG.HHN. ML:0.4 0.000019182216 0.1408 AML other m 2023-09-21T18:03:53.89
IV.SEI.HHE. ML:0.8 0.000042640745 0.5504 AML other m 2023-09-21T18:03:54.18
IV.SEI.HHN. ML:0.8 0.000045623225 0.2688 AML other m 2023-09-21T18:03:54.48
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