Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.3 on date 20-09-2023 and time 09:52:48 (UTC) in region 4 km NE Marradi (FI)

A magnitude ML 0.3 earthquake occured in region: 4 km NE Marradi (FI), on

  • 20-09-2023 09:52:48 (UTC)
  • 20-09-2023 11:52:48 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0950, 11.6510 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 4 3139 3139
Tredozio FC 8 1212 4351
Palazzuolo sul Senio FI 9 1154 5505
Portico e San Benedetto FC 13 756 6261
Modigliana FC 13 4560 10821
Casola Valsenio RA 15 2617 13438
Rocca San Casciano FC 16 1910 15348
Premilcuore FC 17 799 16147
Brisighella RA 17 7639 23786
Castel del Rio BO 18 1246 25032
San Godenzo FI 19 1167 26199
Dovadola FC 19 1653 27852
Fontanelice BO 20 1943 29795

Municipalities with at least 50000 inhabitants

An earthquake occurred to
28 Km SW of Faenza (58541 inhabitants)
29 Km S of Imola (69797 inhabitants)
34 Km W of Forlì (117913 inhabitants)
48 Km W of Cesena (96758 inhabitants)
48 Km NE of Firenze (382808 inhabitants)
50 Km E of Prato (191150 inhabitants)
51 Km SE of Bologna (386663 inhabitants)
53 Km NE of Scandicci (50609 inhabitants)
57 Km SW of Ravenna (159116 inhabitants)
61 Km E of Pistoia (90315 inhabitants)
72 Km N of Arezzo (99543 inhabitants)
73 Km W of Rimini (147750 inhabitants)
83 Km S of Ferrara (133155 inhabitants)
84 Km SE of Modena (184973 inhabitants)
90 Km N of Siena (53903 inhabitants)
96 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 0.3 2023-09-20
09:52:48		 44.0953 11.6512 6 2023-09-20
10:06:59		 Sala Sismica INGV-Roma 121270971
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-20 09:52:48 ± 0.17
Latitude 44.0953 ± 0.0045
Longitude 11.6512 ± 0.0063
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 121270971

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 516
Semi-minor axis of confidence ellipse (meter) 292
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 203
Circular confidence region, given by single value of horizontal uncertainty (meter) 520.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 173
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) 0.16
Epicentral distance of station closest to the epicenter (degree) 0.04407
Epicentral distance of station farthest from the epicenter (degree) 0.21404
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:0.3

Field Value
Value 0.3
Uncertainty 0.4
Num. used stations 6
Type of magnitude ML
Reference to an origin 121270971
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-20 10:06:59
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SEI.HHZ. 2023-09-20T09:52:56.61 0.6 undecidable manual S 259 23.754 103 -0.03 49
IV.RINC.EHZ. 2023-09-20T09:52:56.50 0.6 undecidable manual S 189 23.4543 103 -0.03 49
IV.VISG.HHZ. 2023-09-20T09:52:55.69 0.6 undecidable manual S 301 20.1687 105 0.27 47
IV.VMGN.HHZ. 2023-09-20T09:52:55.25 0.6 undecidable manual S 211 18.2706 107 0.46 45
IV.VMGN.HHZ. 2023-09-20T09:52:52.00 0.6 undecidable manual P 211 18.2706 107 0.01 50
IV.VISG.HHZ. 2023-09-20T09:52:52.39 1.0 positive manual P 301 20.1687 105 0.04 25
IV.SEI.HHZ. 2023-09-20T09:52:52.81 0.3 negative manual P 259 23.754 103 -0.25 70
IV.RINC.EHZ. 2023-09-20T09:52:52.95 0.1 undecidable manual P 189 23.4543 103 -0.04 98
IV.LMD.HHZ. 2023-09-20T09:52:50.82 0.6 undecidable manual S 114 4.8951 139 0.08 50
IT.MRR.HGZ. 2023-09-20T09:52:50.61 0.6 undecidable manual S 228 5.1948 137 -0.19 49
IT.MRR.HGZ. 2023-09-20T09:52:49.60 0.1 undecidable manual P 228 5.1948 137 -0.09 100
IV.LMD.HHZ. 2023-09-20T09:52:49.68 0.3 positive manual P 114 4.8951 139 0.03 76
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:0.0 0.00006301309 0.1984 AML other m 2023-09-20T09:52:52.04
IV.LMD.HHN. ML:0.0 0.00009117001 0.1408 AML other m 2023-09-20T09:52:52.02
IV.VMGN.HHE. ML:0.0 0.000011785158 0.224 AML other m 2023-09-20T09:52:55.43
IV.VMGN.HHN. ML:0.2 0.000014109221 0.3008 AML other m 2023-09-20T09:52:57.52
IV.VISG.HHE. ML:-0.2 0.0000073740765 0.32 AML other m 2023-09-20T09:52:59.19
IV.VISG.HHN. ML:0.3 0.00001405529 0.0832 AML other m 2023-09-20T09:52:56.13
IV.SEI.HHE. ML:0.7 0.000030810385000000005 0.416 AML other m 2023-09-20T09:52:59.60
IV.SEI.HHN. ML:1.0 0.000070564735 0.1984 AML other m 2023-09-20T09:52:56.00
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