Istituto Nazionale di Geofisica e Vulcanologia

Earthquake (quarry blast) with magnitude of ML 1.0 on date 04-08-2021 and time 11:03:39 (Italy) in region 2 km N Vaglia (FI)

A magnitude ML 1.0 (quarry blast) earthquake occured in region: 2 km N Vaglia (FI), on

  • 04-08-2021 09:03:39 (UTC)
  • 04-08-2021 11:03:39 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.9280, 11.2790 at 0 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

Event type: quarry blast.

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
Vaglia FI 2 5073 5073
Scarperia e San Piero FI 5 12217 17290
Barberino di Mugello FI 9 10836 28126
Borgo San Lorenzo FI 9 18211 46337
Calenzano FI 11 17489 63826
Sesto Fiorentino FI 12 48958 112784
Vaiano PO 13 9895 122679
Fiesole FI 13 13969 136648
Vicchio FI 15 8044 144692
Prato PO 15 191150 335842
Campi Bisenzio FI 16 46166 382008
Vernio PO 17 6060 388068
Firenze FI 18 382808 770876
Cantagallo PO 18 3105 773981
Montemurlo PO 19 18456 792437
Bagno a Ripoli FI 20 25611 818048

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km E of Prato (191150 inhabitants)
18 Km N of Firenze (382808 inhabitants)
20 Km NE of Scandicci (50609 inhabitants)
29 Km E of Pistoia (90315 inhabitants)
59 Km SW of Imola (69797 inhabitants)
63 Km SW of Faenza (58541 inhabitants)
63 Km E of Lucca (89046 inhabitants)
63 Km S of Bologna (386663 inhabitants)
68 Km N of Siena (53903 inhabitants)
69 Km W of Forlì (117913 inhabitants)
71 Km NW of Arezzo (99543 inhabitants)
74 Km E of Pisa (89158 inhabitants)
81 Km W of Cesena (96758 inhabitants)
83 Km E of Viareggio (62467 inhabitants)
85 Km SE of Modena (184973 inhabitants)
88 Km E of Livorno (159219 inhabitants)
92 Km SW of Ravenna (159116 inhabitants)
92 Km E of Massa (69479 inhabitants)
96 Km E of Carrara (63133 inhabitants)
100 Km SE of Reggio nell'Emilia (171345 inhabitants)
100 Km SE of Carpi (70699 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 2021-08-04
09:03:39		 43.9278 11.2787 1 2021-12-29
11:12:41		 Bollettino Sismico Italiano INGV 97117231
Reviewed
Rev100 		ML 1.0 2021-08-04
09:03:38		 43.9142 11.2765 8 2021-08-04
09:10:21		 Sala Sismica INGV-Roma 93660151
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-04 09:03:39 ± 0.05
Latitude 43.9278 ± 0.0036
Longitude 11.2787 ± 0.0037
Depth (km) 1 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type quarry blast
Origin ID 97117231

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 390
Semi-minor axis of confidence ellipse (meter) 270
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 6
Circular confidence region, given by single value of horizontal uncertainty (meter) 390.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 121
Number of associated phases, regardless of their use for origin computation 22
Number of defining phases 7
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.11
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.28419
Number of stations at which the event was observed 22
Number of stations from which data was used for origin computation 7
Magnitudes information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.1
Num. used stations 4
Type of magnitude ML
Reference to an origin 97117231
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-10-31 20:36:31

ML:1.0

Field Value
Value 1.0
Uncertainty 0.1
Num. used stations 6
Type of magnitude ML
Reference to an origin 93660151
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-04 09:10:21
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IT.LRNO.HNZ. 2021-08-04T09:05:27.89 3.0 undecidable manual Sg 10.27 0
IV.SPS2.HHZ. 2021-08-04T09:05:25.48 3.0 positive manual Pg 15.2 0
MN.CLTB.HHZ. 2021-08-04T09:05:14.10 3.0 undecidable manual Pn -3.77 0
IV.MTGR.HHZ. 2021-08-04T09:05:12.90 3.0 undecidable manual Pn 0.21 0
CR.STON.BHZ. 2021-08-04T09:04:57.40 3.0 undecidable manual Pn 4.33 0
GU.RORO.HHZ. 2021-08-04T09:04:54.50 3.0 undecidable manual Sg 4.08 0
OX.SABO.HHZ. 2021-08-04T09:04:52.23 3.0 undecidable manual Sn -3.5 0
IV.VOBA.EHZ. 2021-08-04T09:04:32.58 3.0 undecidable manual Sn -2.53 0
CH.FUSIO.HHZ. 2021-08-04T09:04:31.01 3.0 negative manual Pn 1.67 0
IV.VVLD.HNZ. 2021-08-04T09:04:26.08 3.0 undecidable manual Pg 1.18 0
IV.LAV9.HNZ. 2021-08-04T09:04:22.94 3.0 undecidable manual Pg 0.56 0
IV.OFFI.HHZ. 2021-08-04T09:04:19.33 3.0 undecidable manual Pg 4.04 0
IV.CELB.HHZ. 2021-08-04T09:04:06.01 3.0 undecidable manual P -2 0
IV.NDIM.HHZ. 2021-08-04T09:03:57.47 3.0 negative manual P -1.25 0
GU.GSCL.HHZ. 2021-08-04T09:03:51.12 3.0 negative manual P -2.12 0
IV.VISG.HHZ. 2021-08-04T09:03:45.28 0.3 undecidable manual P 23 31.5462 91 -0.08 71
IV.CRMI.HHZ. 2021-08-04T09:03:44.60 0.3 undecidable manual P 239 28.0497 91 -0.07 72
IV.RUFI.EHZ. 2021-08-04T09:03:43.23 0.1 undecidable manual P 118 20.9679 91 -0.02 98
IV.MPPT.EHZ. 2021-08-04T09:03:42.28 0.1 undecidable manual P 282 15.3735 92 0.14 96
IV.SEI.HHZ. 2021-08-04T09:03:42.21 0.1 undecidable manual P 24 15.3735 92 0.08 98
IV.MOCL.EHZ. 2021-08-04T09:03:41.26 0.1 undecidable manual P 318 11.5773 92 -0.11 98
IV.BOSL.HHZ. 2021-08-04T09:03:40.61 0.1 undecidable manual P 87 7.6812 94 0.03 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.MOCL.EHN. ML:1.0 0.00014350000000000002 0.98 AML other m 2021-08-04T09:03:45.62
IV.MOCL.EHE. ML:1.0 0.00016450000000000001 1.04 AML other m 2021-08-04T09:03:46.20
IV.MPPT.EHE. ML:1.0 0.0001275 0.82 AML other m 2021-08-04T09:03:50.32
IV.MPPT.EHN. ML:0.8 0.00007065 0.92 AML other m 2021-08-04T09:03:51.80
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