Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 09-04-2021 and time 00:22:25 (Italy) in region 4 km NW Casalfiumanese (BO)

A magnitude ML 1.1 earthquake occured in region: 4 km NW Casalfiumanese (BO), on

  • 08-04-2021 22:22:25 (UTC)
  • 09-04-2021 00:22:25 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.3220, 11.5740 at 23 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
Casalfiumanese BO 4 3438 3438
Borgo Tossignano BO 5 3288 6726
Dozza BO 6 6652 13378
Fontanelice BO 7 1943 15321
Castel San Pietro Terme BO 9 20811 36132
Casola Valsenio RA 12 2617 38749
Imola BO 12 69797 108546
Riolo Terme RA 13 5720 114266
Castel del Rio BO 13 1246 115512
Monterenzio BO 13 6035 121547
Castel Guelfo di Bologna BO 15 4455 126002
Ozzano dell'Emilia BO 16 13596 139598
Castel Bolognese RA 18 9554 149152
Medicina BO 18 16739 165891
Brisighella RA 19 7639 173530
Pianoro BO 20 17460 190990

Municipalities with at least 50000 inhabitants

An earthquake occurred to
12 Km W of Imola (69797 inhabitants)
25 Km W of Faenza (58541 inhabitants)
27 Km SE of Bologna (386663 inhabitants)
39 Km W of Forlì (117913 inhabitants)
51 Km W of Ravenna (159116 inhabitants)
57 Km W of Cesena (96758 inhabitants)
57 Km S of Ferrara (133155 inhabitants)
62 Km NE of Prato (191150 inhabitants)
63 Km SE of Modena (184973 inhabitants)
66 Km NE of Firenze (382808 inhabitants)
68 Km NE of Pistoia (90315 inhabitants)
70 Km NE of Scandicci (50609 inhabitants)
75 Km SE of Carpi (70699 inhabitants)
84 Km W of Rimini (147750 inhabitants)
85 Km S of Rovigo (51867 inhabitants)
86 Km E of Reggio nell'Emilia (171345 inhabitants)
98 Km N of Arezzo (99543 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 2021-04-08
22:22:25		 44.3217 11.5743 23 2021-04-08
22:35:24		 Sala Sismica INGV-Roma 88923041
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-04-08 22:22:25 ± 0.38
Latitude 44.3217 ± 0.0126
Longitude 11.5743 ± 0.0163
Depth (km) 23 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 88923041

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1479
Semi-minor axis of confidence ellipse (meter) 297
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 150
Circular confidence region, given by single value of horizontal uncertainty (meter) 1480.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 167
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.37
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.46045
Number of stations at which the event was observed 9
Number of stations from which data was used for origin computation 8
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 6
Type of magnitude ML
Reference to an origin 88923041
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-04-08 22:35:24
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.RINC.HHN. 2021-04-08T22:22:42.04 0.6 undecidable manual S 177 48.3183 108 0.71 43
IV.SFI.EHE. 2021-04-08T22:22:42.31 0.6 undecidable manual S 155 51.1155 107 0.28 48
IV.RONT.HHE. 2021-04-08T22:22:39.41 0.3 undecidable manual S 197 38.1285 114 0.63 69
IV.NDIM.HNZ. 2021-04-08T22:22:38.43 3.0 positive manual Pn 0 0
IV.LMD.HHZ. 2021-04-08T22:22:36.18 0.3 undecidable manual S 159 29.0487 122 -0.46 73
IV.SFI.EHE. 2021-04-08T22:22:35.02 0.3 undecidable manual P 155 51.1155 107 0 77
IV.VISG.HHZ. 2021-04-08T22:22:34.34 0.3 undecidable manual S 217 18.4704 136 -0.07 79
IV.IMOL.EHZ. 2021-04-08T22:22:34.40 0.3 undecidable manual S 72 13.9749 145 0.74 67
IV.RINC.HHN. 2021-04-08T22:22:34.59 0.3 undecidable manual P 177 48.3183 108 -0.03 76
IV.BRIS.HHZ. 2021-04-08T22:22:34.14 0.3 undecidable manual S 125 18.6702 136 -0.32 76
IV.RONT.HHE. 2021-04-08T22:22:33.42 0.6 undecidable manual P 197 38.1285 114 0.28 50
IV.LMD.HHZ. 2021-04-08T22:22:31.30 0.3 undecidable manual P 159 29.0487 122 -0.61 69
IV.IMOL.EHZ. 2021-04-08T22:22:30.22 0.3 undecidable manual P 72 13.9749 145 0.03 82
IV.BRIS.HHZ. 2021-04-08T22:22:30.29 0.3 undecidable manual P 125 18.6702 136 -0.36 75
IV.MTRZ.HNZ. 2021-04-08T22:22:30.29 0.3 undecidable manual P 265 11.877 149 0.27 79
IV.VISG.HHZ. 2021-04-08T22:22:30.29 0.1 undecidable manual P 217 18.4704 136 -0.34 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.IMOL.HNE. ML:1.4 0.00015691317499999999 0.1408 AML other m 2021-04-08T22:22:34.87
IV.IMOL.HNN. ML:1.3 0.000122704905 0.1792 AML other m 2021-04-08T22:22:36.12
IV.BRIS.HHE. ML:0.9 0.00004528463 0.128 AML other m 2021-04-08T22:22:34.28
IV.BRIS.HHN. ML:0.9 0.000044655429999999995 0.1152 AML other m 2021-04-08T22:22:34.38
IV.VISG.HHE. ML:1.0 0.000048963919999999995 0.1024 AML other m 2021-04-08T22:22:35.24
IV.VISG.HHN. ML:1.0 0.000051914605 0.1408 AML other m 2021-04-08T22:22:35.16
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