Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 22-09-2023 and time 08:29:48 (UTC) in region 4 km E Marradi (FI)

A magnitude ML 1.1 earthquake occured in region: 4 km E Marradi (FI), on

  • 22-09-2023 08:29:48 (UTC)
  • 22-09-2023 10:29:48 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0890, 11.6580 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 7 1212 4351
Palazzuolo sul Senio FI 9 1154 5505
Portico e San Benedetto FC 12 756 6261
Modigliana FC 13 4560 10821
Rocca San Casciano FC 15 1910 12731
Casola Valsenio RA 15 2617 15348
Premilcuore FC 16 799 16147
Brisighella RA 17 7639 23786
San Godenzo FI 18 1167 24953
Castel del Rio BO 19 1246 26199
Dovadola FC 19 1653 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
28 Km SW of Faenza (58541 inhabitants)
30 Km S of Imola (69797 inhabitants)
34 Km W of Forlì (117913 inhabitants)
47 Km W of Cesena (96758 inhabitants)
48 Km NE of Firenze (382808 inhabitants)
50 Km E of Prato (191150 inhabitants)
52 Km SE of Bologna (386663 inhabitants)
53 Km NE of Scandicci (50609 inhabitants)
57 Km SW of Ravenna (159116 inhabitants)
62 Km E of Pistoia (90315 inhabitants)
71 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
83 Km S of Ferrara (133155 inhabitants)
85 Km SE of Modena (184973 inhabitants)
90 Km NE of Siena (53903 inhabitants)
96 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 1.1 2023-09-22
08:29:48		 44.0888 11.6578 9 2023-09-22
08:38:11		 Sala Sismica INGV-Roma 121347991
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-22 08:29:48 ± 0.15
Latitude 44.0888 ± 0.0072
Longitude 11.6578 ± 0.0063
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 121347991

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 770
Semi-minor axis of confidence ellipse (meter) 246
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 18
Circular confidence region, given by single value of horizontal uncertainty (meter) 770.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 207
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 11
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.17
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.27249
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 6
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 121347991
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-22 08:38:11
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SBPO.HNZ. 2023-09-22T08:30:11.06 3.0 undecidable manual P 1.75 0
IV.RIBO.EHZ.01 2023-09-22T08:30:10.68 3.0 undecidable manual P -0.3 0
IV.SEI.HHZ. 2023-09-22T08:29:57.48 0.6 undecidable manual S 261 24.1536 111 0.17 48
IV.SFI.EHZ. 2023-09-22T08:29:57.88 0.6 undecidable manual S 143 25.3524 110 0.17 48
IV.RINC.EHZ. 2023-09-22T08:29:56.85 0.6 undecidable manual S 190 22.8549 112 -0.03 50
IV.VMGN.HHZ. 2023-09-22T08:29:55.04 0.6 undecidable manual S 214 17.9709 117 -0.29 48
IV.RUFI.EHZ. 2023-09-22T08:29:54.45 0.1 positive manual P 203 30.2475 50 -0.21 95
IV.RINC.EHZ. 2023-09-22T08:29:53.37 0.3 positive manual P 190 22.8549 112 0.1 74
IV.SEI.HHZ. 2023-09-22T08:29:53.54 0.1 undecidable manual P 261 24.1536 111 0.02 100
IV.SFI.EHZ. 2023-09-22T08:29:53.86 0.1 positive manual P 143 25.3524 110 0.11 98
IV.VMGN.HHZ. 2023-09-22T08:29:52.54 0.3 positive manual P 214 17.9709 117 0.16 74
IV.LMD.HHZ. 2023-09-22T08:29:51.50 0.6 undecidable manual S 108 4.0959 156 -0.34 49
IV.LMD.HHZ. 2023-09-22T08:29:50.44 1.0 undecidable manual P 108 4.0959 156 0.08 26
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:1.2 0.00032250000000000003 0.1 AML other m 2023-09-22T08:29:51.64
IV.LMD.HHN. ML:1.1 0.00023349999999999998 0.08 AML other m 2023-09-22T08:29:51.65
IV.VMGN.HHN. ML:0.6 0.00003555 0.3 AML other m 2023-09-22T08:29:56.84
IV.SEI.HHN. ML:1.5 0.000184 0.26 AML other m 2023-09-22T08:29:57.81
IV.VMGN.HHE. ML:0.7 0.00004495 0.56 AML other m 2023-09-22T08:29:57.55
IV.SEI.HHE. ML:1.2 0.0000887 0.62 AML other m 2023-09-22T08:29:57.88
IV.SFI.EHN. ML:1.2 0.00009049999999999999 0.14 AML other m 2023-09-22T08:29:58.50
IV.SFI.EHE. ML:1.1 0.00007685 1.08 AML other m 2023-09-22T08:29:58.70
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