Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.9 on date 21-04-2021 and time 19:39:44 (UTC) in region 3 km W Palazzuolo sul Senio (FI)

A magnitude ML 0.9 earthquake occured in region: 3 km W Palazzuolo sul Senio (FI), on

  • 21-04-2021 19:39:44 (UTC)
  • 21-04-2021 21:39:44 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.1100, 11.5120 at 9 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
Palazzuolo sul Senio FI 3 1154 1154
Marradi FI 9 3139 4293
Firenzuola FI 11 4726 9019
Castel del Rio BO 12 1246 10265
Casola Valsenio RA 16 2617 12882
Fontanelice BO 17 1943 14825
Tredozio FC 19 1212 16037
Borgo Tossignano BO 20 3288 19325
Vicchio FI 20 8044 27369
Monghidoro BO 20 3749 31118
Borgo San Lorenzo FI 20 18211 49329

Municipalities with at least 50000 inhabitants

An earthquake occurred to
32 Km SW of Imola (69797 inhabitants)
36 Km SW of Faenza (58541 inhabitants)
42 Km NE of Prato (191150 inhabitants)
43 Km NE of Firenze (382808 inhabitants)
44 Km W of Forlì (117913 inhabitants)
45 Km SE of Bologna (386663 inhabitants)
47 Km NE of Scandicci (50609 inhabitants)
51 Km E of Pistoia (90315 inhabitants)
58 Km W of Cesena (96758 inhabitants)
65 Km SW of Ravenna (159116 inhabitants)
76 Km SE of Modena (184973 inhabitants)
77 Km NW of Arezzo (99543 inhabitants)
81 Km S of Ferrara (133155 inhabitants)
84 Km W of Rimini (147750 inhabitants)
86 Km E of Lucca (89046 inhabitants)
89 Km N of Siena (53903 inhabitants)
90 Km SE of Carpi (70699 inhabitants)
96 Km SE of Reggio nell'Emilia (171345 inhabitants)
99 Km E of Pisa (89158 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 2021-04-21
19:39:44		 44.11 11.5125 9 2021-07-12
16:55:11		 Bollettino Sismico Italiano INGV 90232531
Reviewed
Rev100 		ML 0.9 2021-04-21
19:39:45		 44.1097 11.5107 9 2021-04-21
19:50:53		 Sala Sismica INGV-Roma 89337241
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-04-21 19:39:44 ± 0.1
Latitude 44.1100 ± 0.0045
Longitude 11.5125 ± 0.0063
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 90232531

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 510
Semi-minor axis of confidence ellipse (meter) 447
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 220
Circular confidence region, given by single value of horizontal uncertainty (meter) 510.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 82
Number of associated phases, regardless of their use for origin computation 27
Number of defining phases 17
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.26
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.37142
Number of stations at which the event was observed 18
Number of stations from which data was used for origin computation 9
Magnitudes information

ML:0.9

Field Value
Value 0.9
Uncertainty 0.4
Num. used stations 12
Type of magnitude ML
Reference to an origin 90232531
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-05-18 14:47:13

ML:0.9

Field Value
Value 0.9
Uncertainty 0.4
Num. used stations 12
Type of magnitude ML
Reference to an origin 89337241
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-04-21 19:50:53
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CET2.HHZ. 2021-04-21T19:41:18.32 3.0 undecidable manual Pg 13.76 0
IT.MCLF.HNZ. 2021-04-21T19:41:16.10 3.0 undecidable manual Sn 5.66 0
IV.LRP.EHZ. 2021-04-21T19:41:14.65 3.0 undecidable manual Sg 14.09 0
IV.VARE.HHZ. 2021-04-21T19:40:24.99 3.0 undecidable manual Pg 1.53 0
IV.MMO1.EHZ. 2021-04-21T19:40:18.77 3.0 negative manual Pg 7.16 0
IV.MILN.HNZ. 2021-04-21T19:40:17.91 3.0 undecidable manual Pg 1.3 0
IV.FOSV.EHZ. 2021-04-21T19:40:07.93 3.0 undecidable manual Pg 4.18 0
IV.ASQU.HHZ. 2021-04-21T19:39:58.79 0.3 undecidable manual S 147 41.2254 50 -0.06 72
IV.SFI.HNN. 2021-04-21T19:39:57.12 0.6 undecidable manual S 130 35.0427 50 -0.1 48
IV.RUFI.EHZ. 2021-04-21T19:39:55.34 3.0 undecidable manual Sg 0
IV.CSNT.HHZ. 2021-04-21T19:39:55.16 3.0 negative manual P -0.54 0
IV.BRIS.HHZ. 2021-04-21T19:39:54.31 0.3 undecidable manual S 58 23.8539 111 0.45 69
IV.RINC.HHN. 2021-04-21T19:39:54.70 0.6 undecidable manual S 163 25.9518 110 0.18 48
IV.SFI.HNN. 2021-04-21T19:39:52.08 0.1 undecidable manual P 130 35.0427 50 0.03 98
IV.ASQU.HHZ. 2021-04-21T19:39:52.93 1.0 undecidable manual P 147 41.2254 50 -0.06 24
IV.RUFI.EHZ. 2021-04-21T19:39:52.15 3.0 undecidable manual Pg 0
IV.LMD.HHZ. 2021-04-21T19:39:51.23 0.3 undecidable manual S 103 15.9729 120 -0.14 74
IV.RONT.HHZ. 2021-04-21T19:39:51.34 0.6 undecidable manual S 206 14.3745 123 0.43 47
IV.MTRZ.HHZ. 2021-04-21T19:39:50.66 0.1 undecidable manual P 343 23.5542 111 0.61 87
IV.SEI.HHZ. 2021-04-21T19:39:50.81 0.6 undecidable manual S 243 13.7751 124 0.09 50
IV.BRIS.HHZ. 2021-04-21T19:39:50.04 0.1 undecidable manual P 58 23.8539 111 -0.07 99
IV.RINC.HHN. 2021-04-21T19:39:50.37 0.1 undecidable manual P 163 25.9518 110 -0.13 98
IV.VISG.HHZ. 2021-04-21T19:39:49.29 0.6 undecidable manual S 325 10.7781 131 -0.61 45
IV.LMD.HHZ. 2021-04-21T19:39:48.46 0.1 undecidable manual P 103 15.9729 120 -0.21 98
IV.RONT.HHZ. 2021-04-21T19:39:48.57 0.1 positive manual P 206 14.3745 123 0.16 99
IV.SEI.HHZ. 2021-04-21T19:39:48.17 0.1 undecidable manual P 243 13.7751 124 -0.12 100
IV.VISG.HHZ. 2021-04-21T19:39:47.50 0.1 undecidable manual P 325 10.7781 131 -0.32 96
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VISG.HHE. ML:1.2 0.000191 0.44 AML other m 2021-04-21T19:39:49.36
IV.VISG.HHN. ML:1.2 0.000188 0.1 AML other m 2021-04-21T19:39:49.57
IV.SEI.HHE. ML:1.1 0.00014528435 1.8464 AML other m 2021-04-21T19:39:51.96
IV.SEI.HHN. ML:1.7 0.0005238585500000001 1.7952 AML other m 2021-04-21T19:39:51.97
IV.RONT.HHE. ML:1.3 0.0001915 0.44 AML other m 2021-04-21T19:39:52.44
IV.RONT.HHN. ML:1.4 0.000243 0.36 AML other m 2021-04-21T19:39:52.97
IV.LMD.HHE. ML:0.4 0.000025099999999999997 1.24 AML other m 2021-04-21T19:39:53.31
IV.LMD.HHN. ML:0.5 0.000029449999999999998 0.66 AML other m 2021-04-21T19:39:57.38
IV.ASQU.HHE. ML:0.5 0.0000078489085 1.0496 AML other m 2021-04-21T19:39:59.07
IV.ASQU.HHN. ML:0.5 0.000008161778 0.2176 AML other m 2021-04-21T19:39:59.58
IV.BRIS.HHN. ML:0.7 0.000030502625 0.3584 AML other m 2021-04-21T19:40:00.66
IV.BRIS.HHE. ML:0.8 0.00003272523 1.5904 AML other m 2021-04-21T19:40:01.93
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