Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 1.4 on date 28-10-2023 and time 04:21:22 (UTC) in region 2 km E Marradi (FI)

A magnitude Md 1.4 earthquake occured in region: 2 km E Marradi (FI), on

  • 28-10-2023 04:21:22 (UTC)
  • 28-10-2023 06:21:22 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0730, 11.6360 at 10 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 9 1212 5505
Portico e San Benedetto FC 13 756 6261
Premilcuore FC 15 799 7060
Modigliana FC 16 4560 11620
San Godenzo FI 16 1167 12787
Rocca San Casciano FC 17 1910 14697
Casola Valsenio RA 17 2617 17314
Castel del Rio BO 19 1246 18560
Brisighella RA 20 7639 26199

Municipalities with at least 50000 inhabitants

An earthquake occurred to
31 Km SW of Faenza (58541 inhabitants)
32 Km S of Imola (69797 inhabitants)
36 Km W of Forlì (117913 inhabitants)
45 Km NE of Firenze (382808 inhabitants)
48 Km E of Prato (191150 inhabitants)
49 Km W of Cesena (96758 inhabitants)
50 Km NE of Scandicci (50609 inhabitants)
53 Km SE of Bologna (386663 inhabitants)
59 Km SW of Ravenna (159116 inhabitants)
60 Km E of Pistoia (90315 inhabitants)
70 Km N of Arezzo (99543 inhabitants)
74 Km W of Rimini (147750 inhabitants)
85 Km S of Ferrara (133155 inhabitants)
85 Km SE of Modena (184973 inhabitants)
87 Km N of Siena (53903 inhabitants)
94 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 		Md 1.4 2023-10-28
04:21:22		 44.0728 11.6365 10 2023-10-28
04:28:00		 Sala Sismica INGV-Roma 122492831
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-10-28 04:21:22 ± 0.09
Latitude 44.0728 ± 0.0036
Longitude 11.6365 ± 0.0050
Depth (km) 10 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 122492831

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 442
Semi-minor axis of confidence ellipse (meter) 350
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 55
Circular confidence region, given by single value of horizontal uncertainty (meter) 440.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 136
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 16
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) 0.05126
Epicentral distance of station farthest from the epicenter (degree) 0.33455
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitude information

Md:1.4

Field Value
Value 1.4
Uncertainty 0.2
Num. used stations 5
Type of magnitude Md
Reference to an origin 122492831
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-10-28 04:28:00
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MOCL.EHZ. 2023-10-28T04:21:35.13 0.1 undecidable manual S 258 37.1295 50 0.14 93
IV.BOSL.HHZ. 2023-10-28T04:21:32.23 0.1 undecidable manual S 233 26.1516 111 0.17 94
IV.RUFI.EHZ. 2023-10-28T04:21:32.32 0.1 undecidable manual S 201 27.9498 50 -0.23 94
IV.RINC.EHZ. 2023-10-28T04:21:30.64 0.1 undecidable manual S 187 20.7681 115 0.3 94
IV.VISG.HHZ. 2023-10-28T04:21:30.41 0.1 undecidable manual S 309 20.5683 116 0.13 97
IV.SEI.HHZ. 2023-10-28T04:21:30.62 0.1 undecidable manual S 265 22.2555 114 -0.18 95
IV.MOCL.EHZ. 2023-10-28T04:21:29.58 1.0 undecidable manual P 258 37.1295 50 -0.07 24
IV.RUFI.EHZ. 2023-10-28T04:21:28.06 0.1 negative manual P 201 27.9498 50 -0.18 95
IV.VMGN.HHZ. 2023-10-28T04:21:28.51 0.1 undecidable manual S 212 15.5733 122 -0.22 95
IV.SEI.HHZ. 2023-10-28T04:21:27.03 1.0 undecidable manual P 265 22.2555 114 -0.2 24
IV.RINC.EHZ. 2023-10-28T04:21:27.18 0.3 positive manual P 187 20.7681 115 0.21 71
IV.BOSL.HHZ. 2023-10-28T04:21:27.97 1.0 negative manual P 233 26.1516 111 0.01 24
IV.VISG.HHZ. 2023-10-28T04:21:26.89 0.3 positive manual P 309 20.5683 116 -0.04 74
IV.LMD.HHZ. 2023-10-28T04:21:26.16 0.1 undecidable manual S 85 5.6943 150 -0.13 99
IV.VMGN.HHZ. 2023-10-28T04:21:26.13 0.1 positive manual P 212 15.5733 122 0.09 98
IV.LMD.HHZ. 2023-10-28T04:21:24.70 0.1 undecidable manual P 85 5.6943 150 0.07 100
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