Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.9 on date 04-09-2020 and time 23:42:50 (Italy) in region 4 km SW Forlì (FC)

A magnitude ML 0.9 earthquake occured in region: 4 km SW Forlì (FC), on

  • 04-09-2020 21:42:50 (UTC)
  • 04-09-2020 23:42:50 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.1920, 12.0210 at 26 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
Forlì FC 4 117913 117913
Castrocaro Terme e Terra del Sole FC 6 6426 124339
Meldola FC 8 9970 134309
Forlimpopoli FC 9 13290 147599
Bertinoro FC 10 11059 158658
Predappio FC 10 6346 165004
Dovadola FC 13 1653 166657
Faenza RA 15 58541 225198
Modigliana FC 19 4560 229758
Cesena FC 19 96758 326516

Municipalities with at least 50000 inhabitants

An earthquake occurred to
4 Km SW of Forlì (117913 inhabitants)
15 Km SE of Faenza (58541 inhabitants)
19 Km W of Cesena (96758 inhabitants)
29 Km SW of Ravenna (159116 inhabitants)
30 Km SE of Imola (69797 inhabitants)
46 Km W of Rimini (147750 inhabitants)
64 Km SE of Bologna (386663 inhabitants)
77 Km NE of Firenze (382808 inhabitants)
78 Km W of Pesaro (94582 inhabitants)
79 Km SE of Ferrara (133155 inhabitants)
81 Km N of Arezzo (99543 inhabitants)
81 Km E of Prato (191150 inhabitants)
83 Km NE of Scandicci (50609 inhabitants)
89 Km W of Fano (60888 inhabitants)
93 Km E of Pistoia (90315 inhabitants)
100 Km S of Rovigo (51867 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 0.9 2020-09-04
21:42:50		 44.1917 12.0207 26 2021-02-26
14:56:07		 Bollettino Sismico Italiano INGV 84964111
Reviewed
Rev100 		ML 0.8 2020-09-04
21:42:50		 44.1407 12.091 2 2020-09-04
21:56:49		 Sala Sismica INGV-Roma 82629501
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2020-09-04 21:42:50 ± 0.49
Latitude 44.1917 ± 0.0135
Longitude 12.0207 ± 0.0201
Depth (km) 26 ± 3 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 84964111

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1658
Semi-minor axis of confidence ellipse (meter) 1173
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 260
Circular confidence region, given by single value of horizontal uncertainty (meter) 1660.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 139
Number of associated phases, regardless of their use for origin computation 26
Number of defining phases 11
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.39
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.57467
Number of stations at which the event was observed 18
Number of stations from which data was used for origin computation 6
Magnitudes information

ML:0.9

Field Value
Value 0.9
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 84964111
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2020-11-23 11:15:46

ML:0.8

Field Value
Value 0.8
Uncertainty 0.2
Num. used stations 8
Type of magnitude ML
Reference to an origin 82629501
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2020-09-04 21:56:49
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CMPR.HHZ. 2020-09-04T21:44:44.10 3.0 undecidable manual Sn -4.54 0
CR.STON.BHZ. 2020-09-04T21:44:38.78 3.0 undecidable manual Sn -0.59 0
IV.PANTE.HHZ. 2020-09-04T21:44:33.92 3.0 undecidable manual Pn -2.81 0
IV.PTRJ.HHZ. 2020-09-04T21:44:23.58 3.0 undecidable manual Sg 4.23 0
IV.PAOL.HHZ. 2020-09-04T21:44:19.40 3.0 undecidable manual Sn -7.53 0
IV.CGL.BHZ. 2020-09-04T21:44:17.02 3.0 negative manual Pg 8.15 0
IV.VAGA.HHZ. 2020-09-04T21:44:03.90 3.0 undecidable manual Sn -9.99 0
IV.CMPR.HHZ. 2020-09-04T21:43:59.89 3.0 undecidable manual Pg 3.74 0
IV.VIVA.HHZ. 2020-09-04T21:43:52.15 3.0 undecidable manual Sn -8.4 0
IV.PTRJ.HNZ. 2020-09-04T21:43:35.37 3.0 undecidable manual Pn -4.32 0
IV.VIVA.HHZ. 2020-09-04T21:43:31.04 3.0 undecidable manual Pg 1.91 0
IV.VARE.HHZ. 2020-09-04T21:43:31.05 3.0 negative manual Pn -5.76 0
IV.SRES.HHZ. 2020-09-04T21:43:21.07 3.0 undecidable manual Pg -1.21 0
IV.FREG.EHZ. 2020-09-04T21:43:18.63 3.0 positive manual Pg -0.72 0
IV.MBAL.EHZ. 2020-09-04T21:43:14.14 3.0 positive manual Pn -5.91 0
IV.PARC.HHZ. 2020-09-04T21:43:10.64 0.6 undecidable manual S 164 62.6928 106 0.41 45
IV.ASQU.HHZ. 2020-09-04T21:43:06.93 0.6 undecidable manual S 203 47.5191 112 0.53 45
IV.PARC.HHZ. 2020-09-04T21:43:02.04 0.1 undecidable manual P 164 62.6928 106 0.14 95
IV.SFI.EHZ. 2020-09-04T21:43:02.78 0.3 undecidable manual S 204 34.743 120 -0.52 69
IV.CRE.HHZ. 2020-09-04T21:43:02.02 0.3 undecidable manual P 185 63.7917 106 -0.03 73
IV.BRIS.HHZ. 2020-09-04T21:43:00.51 0.3 undecidable manual S 280 20.5683 137 0.19 76
IV.BRSN.EHZ. 2020-09-04T21:42:59.45 0.6 undecidable manual S 25 11.2776 153 0.56 48
IV.ASQU.HHZ. 2020-09-04T21:42:59.53 0.3 undecidable manual P 203 47.5191 112 -0.15 74
IV.SFI.EHZ. 2020-09-04T21:42:57.18 0.3 undecidable manual P 204 34.743 120 -0.71 65
IV.BRIS.HHZ. 2020-09-04T21:42:56.51 0.3 undecidable manual P 280 20.5683 137 0.34 73
IV.BRSN.EHZ. 2020-09-04T21:42:54.98 0.1 undecidable manual P 25 11.2776 153 -0.37 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.BRSN.EHN. ML:1.6 0.0002205 0.28 AML other m 2020-09-04T21:42:59.47
IV.BRSN.EHE. ML:1.6 0.00020050000000000002 0.46 AML other m 2020-09-04T21:42:59.70
IV.SFI.EHE. ML:0.8 0.000019028499999999996 0.42 AML other m 2020-09-04T21:43:04.32
IV.SFI.EHN. ML:0.8 0.00002098 0.94 AML other m 2020-09-04T21:43:05.51
IV.BRIS.HHN. ML:0.9 0.000037500000000000003 0.42 AML other m 2020-09-04T21:43:06.49
IV.BRIS.HHE. ML:0.9 0.00003845 1.02 AML other m 2020-09-04T21:43:07.67
IV.ASQU.HHN. ML:0.8 0.000012884555 0.2048 AML other m 2020-09-04T21:43:07.62
IV.ASQU.HHE. ML:0.8 0.000016697825 0.1792 AML other m 2020-09-04T21:43:07.76
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