Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.8 on date 23-04-2023 and time 16:19:10 (UTC) in region 4 km E Rocca San Casciano (FC)

A magnitude ML 1.8 earthquake occured in region: 4 km E Rocca San Casciano (FC), on

  • 23-04-2023 16:19:10 (UTC)
  • 23-04-2023 18:19:10 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.0560, 11.8880 at 27 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

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
Rocca San Casciano FC 4 1910 1910
Galeata FC 7 2516 4426
Civitella di Romagna FC 7 3786 8212
Dovadola FC 7 1653 9865
Predappio FC 9 6346 16211
Portico e San Benedetto FC 9 756 16967
Tredozio FC 12 1212 18179
Santa Sofia FC 12 4136 22315
Premilcuore FC 13 799 23114
Modigliana FC 14 4560 27674
Castrocaro Terme e Terra del Sole FC 14 6426 34100
Meldola FC 16 9970 44070

Municipalities with at least 50000 inhabitants

An earthquake occurred to
22 Km SW of Forlì (117913 inhabitants)
26 Km S of Faenza (58541 inhabitants)
30 Km W of Cesena (96758 inhabitants)
36 Km SE of Imola (69797 inhabitants)
47 Km SW of Ravenna (159116 inhabitants)
54 Km W of Rimini (147750 inhabitants)
60 Km NE of Firenze (382808 inhabitants)
65 Km SE of Bologna (386663 inhabitants)
65 Km N of Arezzo (99543 inhabitants)
66 Km NE of Scandicci (50609 inhabitants)
66 Km E of Prato (191150 inhabitants)
79 Km E of Pistoia (90315 inhabitants)
84 Km W of Pesaro (94582 inhabitants)
89 Km S of Ferrara (133155 inhabitants)
93 Km NE of Siena (53903 inhabitants)
94 Km W of Fano (60888 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
Bulletin
Rev1000 		ML 1.8 2023-04-23
16:19:10		 44.0557 11.8882 27 2024-03-01
17:18:10		 Bollettino Sismico Italiano INGV 117940511
Reviewed
Rev100 		ML 1.9 2023-04-23
16:19:09		 44.0688 11.901 31 2023-04-23
16:26:13		 Sala Sismica INGV-Roma 116656541
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-04-23 16:19:10 ± 0.25
Latitude 44.0557 ± 0.0099
Longitude 11.8882 ± 0.0175
Depth (km) 27 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 117940511

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1362
Semi-minor axis of confidence ellipse (meter) 907
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 45
Circular confidence region, given by single value of horizontal uncertainty (meter) 1360.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 216
Number of associated phases, regardless of their use for origin computation 14
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.28
Epicentral distance of station closest to the epicenter (degree) 0.13130
Epicentral distance of station farthest from the epicenter (degree) 0.47934
Number of stations at which the event was observed 7
Number of stations from which data was used for origin computation 7
Magnitudes information

ML:1.8

Field Value
Value 1.8
Uncertainty 0.2
Num. used stations 4
Type of magnitude ML
Reference to an origin 117940511
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2024-02-09 15:44:08

ML:1.9

Field Value
Value 1.9
Uncertainty 0.2
Num. used stations 4
Type of magnitude ML
Reference to an origin 116656541
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-04-23 16:26:13
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.PARC.HHZ. 2023-04-23T16:19:28.23 0.6 undecidable manual S 148 53.2023 111 0.73 41
IV.CRE.HHZ. 2023-04-23T16:19:26.64 0.3 undecidable manual S 174 48.7179 113 0.24 71
IV.SEI.HHZ. 2023-04-23T16:19:25.15 0.3 undecidable manual S 270 42.2244 117 0.32 70
IV.VISG.HHN. 2023-04-23T16:19:24.76 0.6 undecidable manual S 292 39.0276 119 0.69 42
IV.RUFI.EHZ. 2023-04-23T16:19:23.79 0.6 undecidable manual S 232 38.7279 119 -0.2 49
IV.PARC.HHZ. 2023-04-23T16:19:20.19 0.3 undecidable manual P 148 53.2023 111 0.06 74
IV.CRE.HHZ. 2023-04-23T16:19:19.31 0.3 undecidable manual P 174 48.7179 113 -0.19 72
IV.SFI.HNZ. 2023-04-23T16:19:19.47 0.6 undecidable manual S 191 17.0718 144 -0.12 52
IV.LMD.HHZ. 2023-04-23T16:19:19.27 0.6 undecidable manual S 280 14.5743 148 0.04 52
IV.VISG.HHN. 2023-04-23T16:19:18.13 0.3 undecidable manual P 292 39.0276 119 -0.02 75
IV.SEI.HHZ. 2023-04-23T16:19:18.69 0.1 undecidable manual P 270 42.2244 117 0.1 99
IV.RUFI.EHZ. 2023-04-23T16:19:17.78 0.1 undecidable manual P 232 38.7279 119 -0.32 95
IV.LMD.HHZ. 2023-04-23T16:19:15.09 0.1 undecidable manual P 280 14.5743 148 -0.26 100
IV.SFI.HNZ. 2023-04-23T16:19:15.28 0.1 undecidable manual P 191 17.0718 144 -0.28 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHN. ML:2.0 0.0005365 0.28 AML other m 2023-04-23T16:19:19.58
IV.LMD.HHE. ML:1.8 0.000315 0.4 AML other m 2023-04-23T16:19:19.57
IV.SEI.HHE. ML:1.6 0.00010455000000000001 0.28 AML other m 2023-04-23T16:19:25.64
IV.SEI.HHN. ML:2.0 0.000247 0.34 AML other m 2023-04-23T16:19:25.63
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