Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 22-09-2023 and time 00:08:25 (UTC) in region 4 km E Marradi (FI)

A magnitude ML 1.0 earthquake occured in region: 4 km E Marradi (FI), on

  • 22-09-2023 00:08:25 (UTC)
  • 22-09-2023 02:08:25 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0770, 11.6680 at 9 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 4 3139 3139
Tredozio FC 6 1212 4351
Palazzuolo sul Senio FI 10 1154 5505
Portico e San Benedetto FC 11 756 6261
Modigliana FC 13 4560 10821
Rocca San Casciano FC 14 1910 12731
Premilcuore FC 14 799 13530
Casola Valsenio RA 17 2617 16147
San Godenzo FI 17 1167 17314
Brisighella RA 18 7639 24953
Dovadola FC 18 1653 26606
Castel del Rio BO 20 1246 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
29 Km SW of Faenza (58541 inhabitants)
31 Km S of Imola (69797 inhabitants)
34 Km W of Forlì (117913 inhabitants)
46 Km W of Cesena (96758 inhabitants)
47 Km NE of Firenze (382808 inhabitants)
51 Km E of Prato (191150 inhabitants)
53 Km NE of Scandicci (50609 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
57 Km SW of Ravenna (159116 inhabitants)
62 Km E of Pistoia (90315 inhabitants)
70 Km N of Arezzo (99543 inhabitants)
72 Km W of Rimini (147750 inhabitants)
85 Km S of Ferrara (133155 inhabitants)
87 Km SE of Modena (184973 inhabitants)
89 Km NE of Siena (53903 inhabitants)
97 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 1.0 2023-09-22
00:08:25		 44.0773 11.668 9 2023-09-22
00:21:14		 Sala Sismica INGV-Roma 121332771
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-22 00:08:25 ± 0.18
Latitude 44.0773 ± 0.0072
Longitude 11.6680 ± 0.0075
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121332771

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 858
Semi-minor axis of confidence ellipse (meter) 335
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 32
Circular confidence region, given by single value of horizontal uncertainty (meter) 860.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 146
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) 0.19
Epicentral distance of station closest to the epicenter (degree) 0.02788
Epicentral distance of station farthest from the epicenter (degree) 0.26530
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:1.0

Field Value
Value 1.0
Uncertainty 0.2
Num. used stations 8
Type of magnitude ML
Reference to an origin 121332771
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-22 00:21:14
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.RUFI.EHZ. 2023-09-22T00:08:36.34 0.6 undecidable manual S 206 29.4483 50 -0.31 94
IV.SFI.EHZ. 2023-09-22T00:08:35.12 0.6 undecidable manual S 143 23.8539 111 0.25 96
IV.VISG.HHZ. 2023-09-22T00:08:34.64 0.6 undecidable manual S 304 22.3554 113 0.26 96
IV.SEI.HHZ. 2023-09-22T00:08:34.92 0.6 undecidable manual S 264 24.753 111 -0.25 96
IV.VMGN.HHZ. 2023-09-22T00:08:32.94 0.6 undecidable manual S 218 17.3715 118 0.12 100
IV.RUFI.EHZ. 2023-09-22T00:08:32.05 1.0 positive manual P 206 29.4483 50 -0.08 49
IV.SFI.EHZ. 2023-09-22T00:08:31.29 0.6 negative manual P 143 23.8539 111 0.18 98
IV.SEI.HHZ. 2023-09-22T00:08:31.33 1.0 positive manual P 264 24.753 111 0.05 50
IV.VISG.HHZ. 2023-09-22T00:08:31.01 1.0 undecidable manual P 304 22.3554 113 0.19 49
IV.VMGN.HHZ. 2023-09-22T00:08:30.22 1.0 negative manual P 218 17.3715 118 0.3 48
IV.LMD.HHZ. 2023-09-22T00:08:28.88 0.6 undecidable manual S 90 3.0969 162 -0.52 94
IV.LMD.HHZ. 2023-09-22T00:08:27.95 1.0 undecidable manual P 90 3.0969 162 0 52
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VMGN.HHN. ML:0.8 0.000059749999999999995 0.3 AML other m 2023-09-22T00:08:33.40
IV.VMGN.HHE. ML:0.8 0.000054900000000000006 0.72 AML other m 2023-09-22T00:08:34.45
IV.VISG.HHE. ML:0.7 0.000033299999999999996 0.16 AML other m 2023-09-22T00:08:35.04
IV.SEI.HHE. ML:1.1 0.00007965 0.46 AML other m 2023-09-22T00:08:35.27
IV.VISG.HHN. ML:0.8 0.0000434 0.88 AML other m 2023-09-22T00:08:35.98
IV.SFI.EHN. ML:1.2 0.00008865 0.46 AML other m 2023-09-22T00:08:35.56
IV.SFI.EHE. ML:1.2 0.00008765 1.18 AML other m 2023-09-22T00:08:35.20
IV.SEI.HHN. ML:1.3 0.0001275 0.32 AML other m 2023-09-22T00:08:37.49
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