Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 09-04-2021 and time 17:50:57 (UTC) in region 4 km N Firenzuola (FI)

A magnitude ML 1.0 earthquake occured in region: 4 km N Firenzuola (FI), on

  • 09-04-2021 17:50:57 (UTC)
  • 09-04-2021 19:50:57 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.1550, 11.3780 at 6 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.

Hai sentito il terremoto? Clicca qui

Did you feel it? Fill in the questionnaire.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Firenzuola FI 4 4726 4726
Monghidoro BO 9 3749 8475
Castel del Rio BO 12 1246 9721
San Benedetto Val di Sambro BO 13 4315 14036
Loiano BO 14 4294 18330
Palazzuolo sul Senio FI 14 1154 19484
Monzuno BO 16 6328 25812
Castiglione dei Pepoli BO 18 5648 31460
Fontanelice BO 19 1943 33403
Monterenzio BO 19 6035 39438

Municipalities with at least 50000 inhabitants

An earthquake occurred to
35 Km SW of Imola (69797 inhabitants)
38 Km NE of Prato (191150 inhabitants)
38 Km S of Bologna (386663 inhabitants)
43 Km W of Faenza (58541 inhabitants)
44 Km N of Firenze (382808 inhabitants)
44 Km NE of Pistoia (90315 inhabitants)
47 Km NE of Scandicci (50609 inhabitants)
54 Km W of Forlì (117913 inhabitants)
65 Km SE of Modena (184973 inhabitants)
69 Km W of Cesena (96758 inhabitants)
72 Km W of Ravenna (159116 inhabitants)
78 Km E of Lucca (89046 inhabitants)
78 Km S of Ferrara (133155 inhabitants)
80 Km SE of Carpi (70699 inhabitants)
85 Km SE of Reggio nell'Emilia (171345 inhabitants)
87 Km NW of Arezzo (99543 inhabitants)
92 Km NE of Pisa (89158 inhabitants)
93 Km N of Siena (53903 inhabitants)
95 Km W of Rimini (147750 inhabitants)
96 Km E of Viareggio (62467 inhabitants)
100 Km E of Massa (69479 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 1.0 2021-04-09
17:50:57		 44.1547 11.3782 6 2021-07-12
16:55:13		 Bollettino Sismico Italiano INGV 90720121
Reviewed
Rev100 		ML 1.4 2021-04-09
17:50:57		 44.1543 11.3795 7 2021-04-09
17:59:04		 Sala Sismica INGV-Roma 88946531
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-04-09 17:50:57 ± 0.21
Latitude 44.1547 ± 0.0054
Longitude 11.3782 ± 0.0088
Depth (km) 6 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 90720121

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 687
Semi-minor axis of confidence ellipse (meter) 203
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 310
Circular confidence region, given by single value of horizontal uncertainty (meter) 690.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 90
Number of associated phases, regardless of their use for origin computation 30
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.3
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.34804
Number of stations at which the event was observed 23
Number of stations from which data was used for origin computation 8
Magnitudes information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.4
Num. used stations 6
Type of magnitude ML
Reference to an origin 90720121
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-06-05 00:39:12

ML:1.4

Field Value
Value 1.4
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 88946531
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-04-09 17:59:04
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.PTRJ.HNZ. 2021-04-09T17:52:53.38 3.0 undecidable manual Sg 9.15 0
IV.ESML.HHZ. 2021-04-09T17:52:46.26 3.0 positive manual P 3.69 0
IV.LPEL.HHZ. 2021-04-09T17:52:33.46 3.0 undecidable manual Sg 5.89 0
IV.MCI.EHZ. 2021-04-09T17:52:30.28 3.0 undecidable manual Sn -3.53 0
IV.LRP.EHZ. 2021-04-09T17:52:23.25 3.0 undecidable manual Sn -5.08 0
IV.PZUN.HHZ. 2021-04-09T17:52:13.61 3.0 negative manual P 2.18 0
SI.BOSI.HHZ. 2021-04-09T17:52:08.44 3.0 undecidable manual Sg 2.27 0
IT.RMVT.HGZ. 2021-04-09T17:51:44.29 3.0 negative manual P 6.73 0
OX.SABO.HNZ. 2021-04-09T17:51:39.64 3.0 positive manual P 0.9 0
IV.APEC.HHZ. 2021-04-09T17:51:37.13 3.0 undecidable manual S -2.11 0
IV.EUCT.HNZ. 2021-04-09T17:51:29.03 3.0 undecidable manual P -2.55 0
IV.MMO1.EHZ. 2021-04-09T17:51:29.39 3.0 undecidable manual P -1.91 0
IV.SARZ.HHZ. 2021-04-09T17:51:24.93 3.0 undecidable manual P -6.49 0
IV.CPGN.EHZ. 2021-04-09T17:51:17.50 3.0 undecidable manual P 4.55 0
IV.BRIS.HHZ. 2021-04-09T17:51:09.29 0.6 undecidable manual S 76 31.8459 101 0.11 48
IV.NDIM.HHZ. 2021-04-09T17:51:07.51 3.0 positive manual P -6.21 0
IV.ZCCA.HNN. 2021-04-09T17:51:06.25 0.3 undecidable manual P 304 38.628 99 0.5 66
IV.MOCL.EHZ. 2021-04-09T17:51:06.00 0.6 undecidable manual S 224 22.8549 106 -0.15 49
IV.RONT.HHZ. 2021-04-09T17:51:05.08 0.6 undecidable manual S 166 18.3705 109 0.41 46
IV.MTRZ.HHN. 2021-04-09T17:51:05.31 0.6 undecidable manual S 12 17.9709 110 0.8 40
IV.FNVD.HHZ. 2021-04-09T17:51:05.52 0.6 undecidable manual S 274 20.3685 107 0.21 48
IV.BRIS.HHZ. 2021-04-09T17:51:04.21 0.3 undecidable manual P 76 31.8459 101 -0.2 71
IV.SEI.HHE. 2021-04-09T17:51:02.91 0.6 undecidable manual S 188 11.2776 120 0.51 46
IV.MOCL.EHZ. 2021-04-09T17:51:02.32 0.1 undecidable manual P 224 22.8549 106 -0.34 93
IV.FNVD.HHZ. 2021-04-09T17:51:01.86 0.1 undecidable manual P 274 20.3685 107 -0.32 94
IV.RONT.HHZ. 2021-04-09T17:51:01.98 0.3 undecidable manual P 166 18.3705 109 0.17 73
IV.MTRZ.HHN. 2021-04-09T17:51:01.67 0.1 undecidable manual P 12 17.9709 110 -0.05 100
IV.SEI.HHE. 2021-04-09T17:51:00.41 0.3 undecidable manual P 188 11.2776 120 -0.09 75
IV.VISG.HHZ. 2021-04-09T17:51:00.65 0.6 undecidable manual S 50 5.8941 138 -0.27 49
IV.VISG.HHZ. 2021-04-09T17:50:59.34 0.1 undecidable manual P 50 5.8941 138 -0.3 97
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.RONT.HHE. ML:1.2 0.00014050000000000003 0.38 AML other m 2021-04-09T17:51:05.23
IV.RONT.HHN. ML:1.3 0.0001690496 0.1792 AML other m 2021-04-09T17:51:05.46
IV.MOCL.EHN. ML:0.3 0.000013731095000000001 0.1024 AML other m 2021-04-09T17:51:06.50
IV.MOCL.EHE. ML:0.5 0.000021959628 1.6288 AML other m 2021-04-09T17:51:09.98
IV.BRIS.HHN. ML:1.1 0.00005427833 0.2432 AML other m 2021-04-09T17:51:09.47
IV.BRIS.HHE. ML:1.0 0.00004313261 0.6528 AML other m 2021-04-09T17:51:12.79
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