Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.6 on date 31-08-2021 and time 19:29:20 (UTC) in region 1 km NW Premilcuore (FC)

A magnitude ML 1.6 earthquake occured in region: 1 km NW Premilcuore (FC), on

  • 31-08-2021 19:29:20 (UTC)
  • 31-08-2021 21:29:20 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.9830, 11.7720 at 7 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
Premilcuore FC 1 799 799
Portico e San Benedetto FC 5 756 1555
Rocca San Casciano FC 11 1910 3465
Tredozio FC 11 1212 4677
Galeata FC 11 2516 7193
Santa Sofia FC 12 4136 11329
San Godenzo FI 14 1167 12496
Civitella di Romagna FC 14 3786 16282
Marradi FI 16 3139 19421
Dovadola FC 18 1653 21074
Modigliana FC 20 4560 25634

Municipalities with at least 50000 inhabitants

An earthquake occurred to
34 Km SW of Forlì (117913 inhabitants)
35 Km S of Faenza (58541 inhabitants)
41 Km W of Cesena (96758 inhabitants)
42 Km S of Imola (69797 inhabitants)
48 Km E of Firenze (382808 inhabitants)
53 Km E of Scandicci (50609 inhabitants)
55 Km E of Prato (191150 inhabitants)
58 Km N of Arezzo (99543 inhabitants)
59 Km SW of Ravenna (159116 inhabitants)
64 Km W of Rimini (147750 inhabitants)
67 Km SE of Bologna (386663 inhabitants)
69 Km E of Pistoia (90315 inhabitants)
82 Km NE of Siena (53903 inhabitants)
92 Km W of Pesaro (94582 inhabitants)
96 Km S of Ferrara (133155 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 1.6 2021-08-31
19:29:20		 43.9827 11.772 7 2021-12-29
11:12:52		 Bollettino Sismico Italiano INGV 97691591
Reviewed
Rev100 		ML 1.6 2021-08-31
19:29:20		 43.9827 11.7742 7 2021-08-31
20:00:46		 Sala Sismica INGV-Roma 94887151
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-31 19:29:20 ± 0.05
Latitude 43.9827 ± 0.0027
Longitude 11.7720 ± 0.0050
Depth (km) 7 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 97691591

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 369
Semi-minor axis of confidence ellipse (meter) 201
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 43
Circular confidence region, given by single value of horizontal uncertainty (meter) 370.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 96
Number of associated phases, regardless of their use for origin computation 38
Number of defining phases 38
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.09443
Epicentral distance of station farthest from the epicenter (degree) 0.93529
Number of stations at which the event was observed 26
Number of stations from which data was used for origin computation 26
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 26
Type of magnitude ML
Reference to an origin 94887151
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-31 20:00:46

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations 18
Type of magnitude ML
Reference to an origin 97691591
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-11-22 16:13:22
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CRMI.HHZ. 2021-08-31T19:29:42.30 0.6 undecidable manual S 252 66.6777 50 0.45 42
IV.PII.HHZ. 2021-08-31T19:29:39.10 0.6 negative manual P 254 103.8183 50 0.47 39
IV.MPPT.EHZ. 2021-08-31T19:29:38.70 0.6 undecidable manual S 267 54.501 50 0.11 46
IV.PARC.HHZ. 2021-08-31T19:29:38.20 0.3 undecidable manual S 135 52.6029 50 0.11 69
IV.MOCL.EHZ. 2021-08-31T19:29:36.70 0.3 undecidable manual S 273 47.2194 50 0.04 71
IV.CRE.HHZ. 2021-08-31T19:29:35.10 0.6 undecidable manual S 160 42.8238 50 -0.38 44
IV.ATBU.EHZ. 2021-08-31T19:29:35.56 1.0 undecidable manual P 132 83.8494 50 0.01 22
IV.ATPC.HHE. 2021-08-31T19:29:34.58 1.0 undecidable manual P 135 78.1662 50 -0.1 22
IV.ATPI.EHE. 2021-08-31T19:29:34.20 1.0 undecidable manual P 139 77.6667 50 -0.4 21
IV.CAFI.HNN. 2021-08-31T19:29:34.29 0.6 undecidable manual P 168 74.1702 50 0.24 43
IV.CSNT.HHZ. 2021-08-31T19:29:33.22 1.0 undecidable manual P 215 68.4759 50 0.04 23
IV.CRMI.HHZ. 2021-08-31T19:29:33.01 0.3 negative manual P 252 66.6777 50 0.11 68
IV.PE3.EHE. 2021-08-31T19:29:33.19 1.0 undecidable manual P 118 66.0894 50 0.38 21
IV.ATMC.EHE. 2021-08-31T19:29:33.10 1.0 undecidable manual P 150 68.376 50 -0.06 23
IV.VISG.HHZ. 2021-08-31T19:29:33.00 0.3 undecidable manual S 311 35.3424 101 -0.17 71
IV.OSSC.HHE. 2021-08-31T19:29:32.69 0.6 undecidable manual P 220 66.0894 50 -0.13 45
IV.SEI.HHZ. 2021-08-31T19:29:32.80 0.3 undecidable manual S 284 33.9438 102 0.1 72
IV.FNVD.HHZ. 2021-08-31T19:29:31.05 1.0 undecidable manual P 292 55.6998 50 -0.16 23
IV.RUFI.EHZ. 2021-08-31T19:29:30.30 0.6 undecidable manual S 233 26.4513 105 0.14 48
IV.MPPT.EHZ. 2021-08-31T19:29:30.88 0.3 undecidable manual P 267 54.501 50 -0.14 69
IV.CPGN.EHZ. 2021-08-31T19:29:30.34 1.0 undecidable manual P 114 48.2184 50 0.28 22
IV.MTRZ.HNN. 2021-08-31T19:29:30.48 1.0 undecidable manual P 323 45.9207 50 0.78 19
IV.RSM2.HHE. 2021-08-31T19:29:30.73 1.0 undecidable manual P 95 54.0015 50 -0.22 23
IV.BRIS.HHZ. 2021-08-31T19:29:30.90 0.6 undecidable manual S 359 26.8509 105 0.6 43
IV.PARC.HHZ. 2021-08-31T19:29:30.43 1.0 undecidable manual P 135 52.6029 50 -0.3 22
IV.IMOL.EHZ. 2021-08-31T19:29:29.46 0.6 undecidable manual P 357 41.9247 50 0.38 45
IV.MOCL.EHZ. 2021-08-31T19:29:29.68 0.6 positive manual P 273 47.2194 50 -0.23 46
IV.CRE.HHZ. 2021-08-31T19:29:28.60 0.1 undecidable manual P 160 42.8238 50 -0.62 83
IV.ASQU.HHZ. 2021-08-31T19:29:28.50 0.6 undecidable manual S 176 20.6682 109 0.25 48
IV.SEI.HHZ. 2021-08-31T19:29:27.32 0.1 undecidable manual P 284 33.9438 102 -0.3 92
IV.VISG.HHZ. 2021-08-31T19:29:27.57 0.6 undecidable manual P 311 35.3424 101 -0.32 46
IV.BRIS.HHZ. 2021-08-31T19:29:26.34 0.3 negative manual P 359 26.8509 105 0.11 73
IV.RUFI.EHZ. 2021-08-31T19:29:26.19 0.1 positive manual P 233 26.4513 105 0.04 98
IV.LMD.HHZ. 2021-08-31T19:29:25.20 0.3 undecidable manual S 334 11.6772 121 -0.21 73
IV.ASQU.HHZ. 2021-08-31T19:29:25.13 0.1 positive manual P 176 20.6682 109 0.08 98
IV.SFI.EHZ. 2021-08-31T19:29:25.20 0.6 undecidable manual S 145 10.4784 124 0.15 49
IV.LMD.HHZ. 2021-08-31T19:29:23.25 0.1 positive manual P 334 11.6772 121 -0.16 98
IV.SFI.EHZ. 2021-08-31T19:29:23.30 0.1 positive manual P 145 10.4784 124 0.09 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LMD.HHE. ML:0.0 0.0007825 0.32 AML other m 2021-08-31T19:29:25.44
IV.LMD.HHN. ML:0.0 0.0005780000000000001 0.52 AML other m 2021-08-31T19:29:25.85
IV.ASQU.HHE. ML:0.0 0.00048049999999999997 0.16 AML other m 2021-08-31T19:29:29.06
IV.ASQU.HHN. ML:0.0 0.00013466605 0.2304 AML other m 2021-08-31T19:29:29.33
IV.BRIS.HHE. ML:0.0 0.0007375000000000001 0.34 AML other m 2021-08-31T19:29:31.23
IV.BRIS.HHN. ML:0.0 0.00074 0.4 AML other m 2021-08-31T19:29:31.36
IV.CRE.HHN. ML:0.0 0.00027800000000000004 0.36 AML other m 2021-08-31T19:29:35.56
IV.CRE.HHE. ML:0.0 0.00008135000000000001 0.24 AML other m 2021-08-31T19:29:36.13
IV.MOCL.EHE. ML:0.0 0.0000778 0.62 AML other m 2021-08-31T19:29:37.01
IV.MOCL.EHN. ML:0.0 0.00009015000000000001 0.78 AML other m 2021-08-31T19:29:37.87
IV.MPPT.EHE. ML:0.0 0.000041564144999999994 0.256 AML other m 2021-08-31T19:29:39.05
IV.MPPT.EHN. ML:0.0 0.00009518784 0.8064 AML other m 2021-08-31T19:29:39.56
IV.CRMI.HHE. ML:0.0 0.000028471064999999997 1.6032 AML other m 2021-08-31T19:29:42.96
IV.CRMI.HHN. ML:0.0 0.00006456297499999999 1.2576 AML other m 2021-08-31T19:29:43.73
IV.SFI.EHN. ML:0.0 0.0012250000000000002 0.46 AML other m 2021-08-31T19:29:25.36
IV.SFI.HNE. ML:0.0 0.0012400000000000002 0.08 AML other m 2021-08-31T19:29:25.42
IV.SFI.EHE. ML:0.0 0.00124 0.08 AML other m 2021-08-31T19:29:25.42
IV.SFI.HNN. ML:0.0 0.00121 0.46 AML other m 2021-08-31T19:29:25.59
IV.RUFI.EHN. ML:0.0 0.0001336853 1.7056 AML other m 2021-08-31T19:29:31.00
IV.RUFI.EHE. ML:0.0 0.000097065625 1.1008 AML other m 2021-08-31T19:29:30.43
IV.BRIS.HNE. ML:1.2 0.00009305435500000001 3.712 AML other m 2021-08-31T19:29:30.11
IV.BRIS.HNN. ML:1.5 0.00016864714999999998 2.9952 AML other m 2021-08-31T19:29:31.18
IV.SEI.HHN. ML:0.0 0.000617 0.62 AML other m 2021-08-31T19:29:33.36
IV.SEI.HHE. ML:0.0 0.000469 0.24 AML other m 2021-08-31T19:29:33.35
IV.VISG.HHE. ML:0.0 0.00003554289500000001 2.0608 AML other m 2021-08-31T19:29:33.38
IV.VISG.HHN. ML:0.0 0.000055379645000000004 0.2176 AML other m 2021-08-31T19:29:34.14
IV.PARC.HHN. ML:0.0 0.00003584403499999999 0.64 AML other m 2021-08-31T19:29:39.45
IV.PARC.HHE. ML:0.0 0.000022245769999999998 2.5728 AML other m 2021-08-31T19:29:38.41
IV.CRMI.HNE. ML:1.7 0.00008699078999999999 2.4448 AML other m 2021-08-31T19:29:43.33
IV.CRMI.HNN. ML:1.7 0.00009079142849999999 1.9584 AML other m 2021-08-31T19:29:42.59
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