Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.8 on date 28-10-2023 and time 08:37:24 (UTC) in region 2 km SE Marradi (FI)

A magnitude ML 0.8 earthquake occured in region: 2 km SE Marradi (FI), on

  • 28-10-2023 08:37:24 (UTC)
  • 28-10-2023 10:37:24 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0640, 11.6240 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 2 3139 3139
Palazzuolo sul Senio FI 8 1154 4293
Tredozio FC 10 1212 5505
Portico e San Benedetto FC 13 756 6261
San Godenzo FI 15 1167 7428
Premilcuore FC 16 799 8227
Modigliana FC 17 4560 12787
Rocca San Casciano FC 18 1910 14697
Casola Valsenio RA 18 2617 17314
Vicchio FI 19 8044 25358
Castel del Rio BO 19 1246 26604

Municipalities with at least 50000 inhabitants

An earthquake occurred to
32 Km SW of Faenza (58541 inhabitants)
33 Km S of Imola (69797 inhabitants)
38 Km W of Forlì (117913 inhabitants)
44 Km NE of Firenze (382808 inhabitants)
47 Km E of Prato (191150 inhabitants)
49 Km NE of Scandicci (50609 inhabitants)
50 Km W of Cesena (96758 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
58 Km E of Pistoia (90315 inhabitants)
61 Km SW of Ravenna (159116 inhabitants)
70 Km NW of Arezzo (99543 inhabitants)
75 Km W of Rimini (147750 inhabitants)
85 Km SE of Modena (184973 inhabitants)
86 Km S of Ferrara (133155 inhabitants)
86 Km N of Siena (53903 inhabitants)
93 Km E of Lucca (89046 inhabitants)
99 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 0.8 2023-10-28
08:37:24		 44.0638 11.6242 6 2023-10-28
08:48:49		 Sala Sismica INGV-Roma 122503621
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-10-28 08:37:24 ± 0.31
Latitude 44.0638 ± 0.0072
Longitude 11.6242 ± 0.0100
Depth (km) 6 ± 3 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 122503621

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 929
Semi-minor axis of confidence ellipse (meter) 262
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 320
Circular confidence region, given by single value of horizontal uncertainty (meter) 930.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 137
Number of associated phases, regardless of their use for origin computation 15
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.33
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.24012
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 7
Magnitude information

ML:0.8

Field Value
Value 0.8
Uncertainty 0.4
Num. used stations 4
Type of magnitude ML
Reference to an origin 122503621
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-10-28 08:48:49
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.BOSL.HHZ. 2023-10-28T08:37:33.51 0.6 undecidable manual S 234 24.753 104 0.24 47
IV.RUFI.EHZ. 2023-10-28T08:37:33.39 0.6 undecidable manual S 200 26.6511 103 -0.51 44
IV.RINC.EHE. 2023-10-28T08:37:31.63 0.6 undecidable manual S 184 19.6692 108 0.05 49
IV.SEI.HHZ. 2023-10-28T08:37:31.87 0.1 undecidable manual S 267 21.1677 107 -0.2 95
IT.MOG.HNZ. 2023-10-28T08:37:30.81 0.6 undecidable manual S 44 16.3725 111 0.32 47
IV.BOSL.HHZ. 2023-10-28T08:37:30.35 0.1 undecidable manual P 234 24.753 104 0.83 78
IV.VMGN.HHZ. 2023-10-28T08:37:30.26 0.6 undecidable manual S 211 14.1747 114 0.49 45
IV.RUFI.EHZ. 2023-10-28T08:37:29.52 0.1 undecidable manual P 200 26.6511 103 -0.36 91
IV.PTRJ.HHZ. 2023-10-28T08:37:29.32 3.0 undecidable manual Pn -2.5 0
IV.SEI.HHZ. 2023-10-28T08:37:28.53 0.1 undecidable manual P 267 21.1677 107 -0.3 94
IV.RINC.EHE. 2023-10-28T08:37:28.54 0.1 undecidable manual P 184 19.6692 108 0 100
IV.VMGN.HHZ. 2023-10-28T08:37:27.53 0.1 undecidable manual P 211 14.1747 114 0.03 100
IV.LMD.HHZ. 2023-10-28T08:37:27.43 1.0 undecidable manual S 77 6.7932 133 -0.19 25
IT.MOG.HNZ. 2023-10-28T08:37:27.95 0.1 undecidable manual P 44 16.3725 111 0.04 100
IV.LMD.HHZ. 2023-10-28T08:37:26.10 0.1 undecidable manual P 77 6.7932 133 -0.15 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:1.1 0.00018429305 0.1216 AML other m 2023-10-28T08:37:27.56
IV.LMD.HHN. ML:1.0 0.0001855 0.08 AML other m 2023-10-28T08:37:28.03
IV.VMGN.HHE. ML:0.4 0.000032120927 0.2368 AML other m 2023-10-28T08:37:30.51
IV.VMGN.HHN. ML:0.6 0.00004221378 0.1984 AML other m 2023-10-28T08:37:30.62
IV.SEI.HHE. ML:1.0 0.000079559985 0.3008 AML other m 2023-10-28T08:37:32.22
IV.SEI.HHN. ML:1.3 0.00014465785 0.2048 AML other m 2023-10-28T08:37:32.34
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