Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.6 on date 18-07-2021 and time 20:23:30 (UTC) in region 6 km E Loiano (BO)

A magnitude ML 1.6 earthquake occured in region: 6 km E Loiano (BO), on

  • 18-07-2021 20:23:30 (UTC)
  • 18-07-2021 22:23:30 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.2670, 11.3990 at 21 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
Loiano BO 6 4294 4294
Monterenzio BO 7 6035 10329
Monghidoro BO 8 3749 14078
Monzuno BO 10 6328 20406
Castel del Rio BO 10 1246 21652
Fontanelice BO 13 1943 23595
Pianoro BO 14 17460 41055
San Benedetto Val di Sambro BO 14 4315 45370
Borgo Tossignano BO 15 3288 48658
Firenzuola FI 17 4726 53384
Marzabotto BO 17 6779 60163
Casalfiumanese BO 18 3438 63601
Casola Valsenio RA 19 2617 66218
Sasso Marconi BO 19 14735 80953
Grizzana Morandi BO 20 3916 84869

Municipalities with at least 50000 inhabitants

An earthquake occurred to
26 Km S of Bologna (386663 inhabitants)
27 Km W of Imola (69797 inhabitants)
39 Km W of Faenza (58541 inhabitants)
49 Km NE of Prato (191150 inhabitants)
51 Km W of Forlì (117913 inhabitants)
53 Km NE of Pistoia (90315 inhabitants)
56 Km SE of Modena (184973 inhabitants)
56 Km N of Firenze (382808 inhabitants)
59 Km NE of Scandicci (50609 inhabitants)
66 Km S of Ferrara (133155 inhabitants)
66 Km W of Ravenna (159116 inhabitants)
69 Km W of Cesena (96758 inhabitants)
70 Km SE of Carpi (70699 inhabitants)
78 Km SE of Reggio nell'Emilia (171345 inhabitants)
86 Km NE of Lucca (89046 inhabitants)
95 Km SW of Rovigo (51867 inhabitants)
96 Km W of Rimini (147750 inhabitants)
97 Km NW of Arezzo (99543 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 2021-07-18
20:23:30		 44.2673 11.3988 21 2021-12-29
11:12:49		 Bollettino Sismico Italiano INGV 97200631
Reviewed
Rev100 		ML 1.5 2021-07-18
20:23:30		 44.2688 11.4127 23 2021-07-18
20:31:29		 Sala Sismica INGV-Roma 92931221
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-07-18 20:23:30 ± 0.18
Latitude 44.2673 ± 0.0099
Longitude 11.3988 ± 0.0126
Depth (km) 21 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 97200631

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 943
Semi-minor axis of confidence ellipse (meter) 685
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 156
Circular confidence region, given by single value of horizontal uncertainty (meter) 940.0
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 20
Number of defining phases 20
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.35
Epicentral distance of station closest to the epicenter (degree) 0.04946
Epicentral distance of station farthest from the epicenter (degree) 0.55938
Number of stations at which the event was observed 15
Number of stations from which data was used for origin computation 15
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.4
Num. used stations 14
Type of magnitude ML
Reference to an origin 97200631
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-11-03 14:04:07

ML:1.5

Field Value
Value 1.5
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 92931221
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-07-18 20:31:29
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.LMD.HHZ. 2021-07-18T20:23:43.22 0.6 undecidable manual S 131 32.3454 114 0.78 40
IV.CRMI.HNN. 2021-07-18T20:23:42.88 0.3 undecidable manual P 213 62.0934 101 0.96 53
IV.ASQU.HHE. 2021-07-18T20:23:41.64 0.3 undecidable manual P 149 60.7947 101 -0.08 69
GU.POPM.HHZ. 2021-07-18T20:23:41.65 0.3 undecidable manual P 244 56.6988 102 0.54 63
IV.SEI.HHZ. 2021-07-18T20:23:40.84 0.6 undecidable manual S 188 23.8539 123 0.4 47
IV.SFI.EHZ. 2021-07-18T20:23:40.55 0.1 undecidable manual P 138 53.8017 103 -0.12 93
IV.FNVD.HHZ. 2021-07-18T20:23:40.56 0.6 undecidable manual S 243 24.5532 122 -0.05 50
IV.RUFI.EHN. 2021-07-18T20:23:39.80 0.3 undecidable manual P 169 48.4182 105 -0.07 71
IV.MPPT.EHE. 2021-07-18T20:23:39.14 0.3 undecidable manual P 216 42.2244 107 0.19 70
IV.ZCCA.HHZ. 2021-07-18T20:23:38.03 0.3 undecidable manual P 286 34.743 112 0.17 71
IV.MTRZ.HHZ. 2021-07-18T20:23:38.29 0.6 undecidable manual S 22 5.4945 163 0.9 39
IV.BOSL.HHZ. 2021-07-18T20:23:38.15 0.3 undecidable manual P 183 37.3293 110 -0.09 72
IV.VISG.HHZ. 2021-07-18T20:23:37.67 0.6 undecidable manual S 162 9.1797 153 -0.09 51
IV.LMD.HHZ. 2021-07-18T20:23:37.25 0.1 undecidable manual P 131 32.3454 114 -0.27 94
IV.MOCL.EHE. 2021-07-18T20:23:37.56 0.3 undecidable manual P 211 33.9438 113 -0.18 71
IV.IMOL.EHZ. 2021-07-18T20:23:37.19 0.3 undecidable manual P 69 29.1486 117 0.12 73
IV.SEI.HHZ. 2021-07-18T20:23:36.12 0.1 undecidable manual P 188 23.8539 123 -0.25 95
IV.FNVD.HHZ. 2021-07-18T20:23:35.93 0.1 undecidable manual P 243 24.5532 122 -0.53 89
IV.MTRZ.HHZ. 2021-07-18T20:23:34.39 0.1 undecidable manual P 22 5.4945 163 -0.21 100
IV.VISG.HHZ. 2021-07-18T20:23:34.39 0.1 undecidable manual P 162 9.1797 153 -0.42 94
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VISG.HHE. ML:1.6 0.00027749999999999997 0.28 AML other m 2021-07-18T20:23:38.43
IV.VISG.HHN. ML:1.7 0.0003765 0.46 AML other m 2021-07-18T20:23:38.36
IV.MTRZ.HHN. ML:2.2 0.0012200000000000002 0.3 AML other m 2021-07-18T20:23:38.46
IV.MTRZ.HNN. ML:2.2 0.0011400000000000002 0.3 AML other m 2021-07-18T20:23:38.47
IV.MTRZ.HNE. ML:2.2 0.0014 1.38 AML other m 2021-07-18T20:23:39.01
IV.MTRZ.HHE. ML:2.3 0.00157 1.38 AML other m 2021-07-18T20:23:39.01
IV.SEI.HHN. ML:1.9 0.000398 1.02 AML other m 2021-07-18T20:23:41.89
IV.SEI.HHE. ML:1.6 0.000195 0.3 AML other m 2021-07-18T20:23:41.71
IV.LMD.HHE. ML:1.3 0.0000824 0.26 AML other m 2021-07-18T20:23:44.17
IV.LMD.HHN. ML:1.2 0.00006445000000000001 0.88 AML other m 2021-07-18T20:23:44.43
IV.ZCCA.HHE. ML:0.9 0.00003175 1.58 AML other m 2021-07-18T20:23:46.95
IV.ZCCA.HHN. ML:0.9 0.000029749999999999998 0.64 AML other m 2021-07-18T20:23:49.48
IV.SFI.EHE. ML:1.3 0.000038900000000000004 0.78 AML other m 2021-07-18T20:23:51.95
IV.SFI.EHN. ML:1.3 0.00003905 1.06 AML other m 2021-07-18T20:23:51.23
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