Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 31-08-2021 and time 20:00:15 (UTC) in region 6 km E Monterenzio (BO)

A magnitude ML 1.0 earthquake occured in region: 6 km E Monterenzio (BO), on

  • 31-08-2021 20:00:15 (UTC)
  • 31-08-2021 22:00:15 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.3360, 11.4810 at 32 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
Monterenzio BO 6 6035 6035
Fontanelice BO 11 1943 7978
Borgo Tossignano BO 11 3288 11266
Castel San Pietro Terme BO 11 20811 32077
Casalfiumanese BO 12 3438 35515
Dozza BO 12 6652 42167
Ozzano dell'Emilia BO 12 13596 55763
Pianoro BO 12 17460 73223
Castel del Rio BO 14 1246 74469
Loiano BO 15 4294 78763
San Lazzaro di Savena BO 16 32065 110828
Casola Valsenio RA 17 2617 113445
Monzuno BO 18 6328 119773
Monghidoro BO 18 3749 123522
Imola BO 19 69797 193319
Castel Guelfo di Bologna BO 19 4455 197774
Castenaso BO 19 14925 212699
Sasso Marconi BO 20 14735 227434

Municipalities with at least 50000 inhabitants

An earthquake occurred to
19 Km W of Imola (69797 inhabitants)
21 Km SE of Bologna (386663 inhabitants)
33 Km W of Faenza (58541 inhabitants)
46 Km W of Forlì (117913 inhabitants)
56 Km SE of Modena (184973 inhabitants)
57 Km S of Ferrara (133155 inhabitants)
58 Km W of Ravenna (159116 inhabitants)
59 Km NE of Prato (191150 inhabitants)
63 Km NE of Pistoia (90315 inhabitants)
65 Km W of Cesena (96758 inhabitants)
66 Km N of Firenze (382808 inhabitants)
69 Km NE of Scandicci (50609 inhabitants)
69 Km SE of Carpi (70699 inhabitants)
79 Km SE of Reggio nell'Emilia (171345 inhabitants)
85 Km SW of Rovigo (51867 inhabitants)
92 Km W of Rimini (147750 inhabitants)
95 Km NE of Lucca (89046 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 2021-08-31
20:00:15		 44.3363 11.4813 32 2021-12-29
11:12:53		 Bollettino Sismico Italiano INGV 98504071
Reviewed
Rev100 		ML 1.0 2021-08-31
20:00:15		 44.3038 11.548 30 2021-08-31
20:06:52		 Sala Sismica INGV-Roma 94887241
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-31 20:00:15 ± 0.55
Latitude 44.3363 ± 0.0207
Longitude 11.4813 ± 0.0277
Depth (km) 32 ± 3 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 98504071

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 2260
Semi-minor axis of confidence ellipse (meter) 883
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 37
Circular confidence region, given by single value of horizontal uncertainty (meter) 2260.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 239
Number of associated phases, regardless of their use for origin computation 24
Number of defining phases 12
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.41
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.30667
Number of stations at which the event was observed 18
Number of stations from which data was used for origin computation 6
Magnitudes information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.3
Num. used stations 6
Type of magnitude ML
Reference to an origin 98504071
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-12-14 12:13:42

ML:1.0

Field Value
Value 1.0
Uncertainty 0.4
Num. used stations 6
Type of magnitude ML
Reference to an origin 94887241
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-31 20:06:52
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IX.SCL3.EHZ.02 2021-08-31T20:01:43.84 3.0 undecidable manual Pg 21.700001 0
IV.SRES.HHZ. 2021-08-31T20:01:36.95 3.0 undecidable manual Sg 3.03 0
IV.CRAC.EHZ. 2021-08-31T20:01:34.49 3.0 positive manual Pn 3.48 0
IV.IMTC.HHZ. 2021-08-31T20:01:32.30 3.0 negative manual Pg 18.110001 0
IV.VITU.HHZ. 2021-08-31T20:01:15.85 3.0 negative manual Pn 4.1 0
IV.SACR.HHZ. 2021-08-31T20:01:11.27 3.0 undecidable manual Pn 1.7 0
IV.BULT.EHZ. 2021-08-31T20:01:07.57 3.0 undecidable manual Pn -6.1 0
IV.APEC.HHZ. 2021-08-31T20:01:03.28 3.0 undecidable manual Sg 0.26 0
IV.ROM9.HNZ. 2021-08-31T20:00:56.83 3.0 negative manual Pn 1.52 0
GU.BURY.HNZ. 2021-08-31T20:00:43.19 3.0 undecidable manual Pn 1.91 0
IV.LMD.HHZ. 2021-08-31T20:00:29.05 0.6 undecidable manual S 148 33.8439 129 0.41 61
IV.FNVD.HHN. 2021-08-31T20:00:29.48 0.6 undecidable manual S 237 34.0437 129 0.81 54
IV.SEI.HHZ. 2021-08-31T20:00:28.44 0.3 undecidable manual S 197 32.745 130 0.03 100
IV.BRIS.HHZ. 2021-08-31T20:00:27.62 0.6 undecidable manual S 119 25.8519 137 0.56 58
IV.MTRZ.HHZ. 2021-08-31T20:00:24.72 0.6 undecidable manual S 240 5.1948 170 0.2 67
IV.VISG.HHZ. 2021-08-31T20:00:24.67 0.3 undecidable manual S 193 16.7721 149 -0.93 78
IV.FNVD.HHN. 2021-08-31T20:00:23.39 0.3 undecidable manual P 237 34.0437 129 0.47 91
IV.LMD.HHZ. 2021-08-31T20:00:23.07 0.3 undecidable manual P 148 33.8439 129 0.17 96
IV.SEI.HHZ. 2021-08-31T20:00:22.72 0.3 undecidable manual P 197 32.745 130 -0.05 99
IV.BRIS.HHZ. 2021-08-31T20:00:21.69 0.3 undecidable manual P 119 25.8519 137 -0.31 96
IV.VISG.HHZ. 2021-08-31T20:00:20.73 0.3 undecidable manual P 193 16.7721 149 -0.43 94
IV.MTRZ.HHZ. 2021-08-31T20:00:20.22 0.3 undecidable manual P 240 5.1948 170 -0.31 99
IV.TREG.EHZ. 2021-08-31T20:00:17.92 3.0 undecidable manual P 15.02 0
IV.BOZZ.EHZ. 2021-08-31T20:00:09.44 3.0 positive manual P 0.39 0
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VISG.HHE. ML:0.9 0.00003225 0.54 AML other m 2021-08-31T20:00:24.99
IV.VISG.HHN. ML:1.1 0.000047850000000000004 1.36 AML other m 2021-08-31T20:00:24.83
IV.MTRZ.HHE. ML:1.5 0.0001555 0.32 AML other m 2021-08-31T20:00:25.58
IV.MTRZ.HHN. ML:1.5 0.00016 0.74 AML other m 2021-08-31T20:00:25.69
IV.LMD.HHE. ML:0.7 0.00001525 0.28 AML other m 2021-08-31T20:00:30.39
IV.LMD.HHN. ML:0.7 0.0000162 1 AML other m 2021-08-31T20:00:30.16
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