Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.9 on date 21-04-2018 and time 02:47:08 (UTC) in region 2 km W Riolo Terme (RA)

A magnitude ML 1.9 earthquake occured in region: 2 km W Riolo Terme (RA), on

  • 21-04-2018 02:47:08 (UTC)
  • 21-04-2018 04:47:08 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.2680, 11.7010 at 22 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
Riolo Terme RA 2 5720 5720
Casalfiumanese BO 8 3438 9158
Brisighella RA 8 7639 16797
Casola Valsenio RA 8 2617 19414
Borgo Tossignano BO 9 3288 22702
Imola BO 10 69797 92499
Castel Bolognese RA 10 9554 102053
Fontanelice BO 11 1943 103996
Dozza BO 12 6652 110648
Modigliana FC 14 4560 115208
Faenza RA 15 58541 173749
Solarolo RA 15 4488 178237
Castel del Rio BO 17 1246 179483
Bagnara di Romagna RA 17 2429 181912
Mordano BO 17 4760 186672
Castel San Pietro Terme BO 17 20811 207483
Castel Guelfo di Bologna BO 18 4455 211938

Municipalities with at least 50000 inhabitants

An earthquake occurred to
10 Km S of Imola (69797 inhabitants)
15 Km W of Faenza (58541 inhabitants)
28 Km W of Forlì (117913 inhabitants)
38 Km SE of Bologna (386663 inhabitants)
43 Km W of Ravenna (159116 inhabitants)
46 Km W of Cesena (96758 inhabitants)
64 Km S of Ferrara (133155 inhabitants)
65 Km NE of Prato (191150 inhabitants)
66 Km NE of Firenze (382808 inhabitants)
70 Km NE of Scandicci (50609 inhabitants)
73 Km W of Rimini (147750 inhabitants)
73 Km NE of Pistoia (90315 inhabitants)
75 Km SE of Modena (184973 inhabitants)
86 Km SE of Carpi (70699 inhabitants)
90 Km S of Rovigo (51867 inhabitants)
90 Km N of Arezzo (99543 inhabitants)
97 Km E of Reggio nell'Emilia (171345 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 1.9 2018-04-21
02:47:08		 44.2682 11.7013 22 2019-04-24
14:49:49		 Bollettino Sismico Italiano INGV 66045611
Reviewed
Rev100 		ML 1.6 2018-04-21
02:47:09		 44.2322 11.6963 9 2018-04-21
03:03:08		 Sala Sismica INGV-Roma 55897191
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2018-04-21 02:47:08 ± 0.34
Latitude 44.2682 ± 0.0117
Longitude 11.7013 ± 0.0214
Depth (km) 22 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 66045611

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1452
Semi-minor axis of confidence ellipse (meter) 1199
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 311
Circular confidence region, given by single value of horizontal uncertainty (meter) 1450.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 90
Number of associated phases, regardless of their use for origin computation 19
Number of defining phases 19
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.46
Epicentral distance of station closest to the epicenter (degree) 0.06385
Epicentral distance of station farthest from the epicenter (degree) 1.00634
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 12
Magnitudes information

ML:1.9

Field Value
Value 1.9
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 66045611
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2019-02-28 11:24:45

ML:1.6

Field Value
Value 1.6
Uncertainty 0.2
Num. used stations 9
Type of magnitude ML
Reference to an origin 55897191
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2018-04-21 03:03:08
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.PII.HHZ. 2018-04-21T02:47:27.57 0.3 undecidable manual P 238 111.6993 96 0.34 60
IV.ASQU.HHZ. 2018-04-21T02:47:26.24 0.6 undecidable manual S 172 52.8027 105 0.82 37
IV.SFI.HNZ. 2018-04-21T02:47:23.17 0.6 undecidable manual S 164 41.9247 109 0.51 43
IV.SEI.HHZ. 2018-04-21T02:47:21.25 0.6 undecidable manual S 229 36.1416 113 0.04 49
IV.ZCCA.HNN. 2018-04-21T02:47:20.45 1.0 undecidable manual P 279 58.2972 103 1.36 15
IV.MTRZ.HHZ. 2018-04-21T02:47:18.87 0.6 undecidable manual S 283 22.4553 127 0.83 41
IV.ASQU.HHZ. 2018-04-21T02:47:17.97 0.3 undecidable manual P 172 52.8027 105 -0.3 69
IV.FAEN.HNZ. 2018-04-21T02:47:17.84 0.6 undecidable manual S 80 14.1747 142 1.39 31
IV.FNVD.HHZ. 2018-04-21T02:47:17.21 0.3 undecidable manual P 257 47.3193 107 -0.25 69
IV.CMPO.HNZ. 2018-04-21T02:47:16.54 0.3 undecidable manual P 13 35.6421 113 0.77 62
IV.SFI.HNZ. 2018-04-21T02:47:16.25 0.1 undecidable manual P 164 41.9247 109 -0.42 91
IV.IMOL.EHZ. 2018-04-21T02:47:15.55 0.6 undecidable manual S 18 10.6782 150 -0.38 48
IV.SEI.HHZ. 2018-04-21T02:47:15.58 0.3 undecidable manual P 229 36.1416 113 -0.26 71
IV.BRSN.HNZ. 2018-04-21T02:47:15.72 0.3 undecidable manual P 87 30.1476 118 0.72 63
IV.BRIS.HHZ. 2018-04-21T02:47:15.20 0.3 undecidable manual S 133 7.0929 159 -0.33 74
IV.MTRZ.HHZ. 2018-04-21T02:47:13.95 0.1 undecidable manual P 283 22.4553 127 -0.06 100
IV.BRIS.HHZ. 2018-04-21T02:47:12.01 0.1 positive manual P 133 7.0929 159 -0.55 93
IV.IMOL.EHZ. 2018-04-21T02:47:12.19 0.1 undecidable manual P 18 10.6782 150 -0.6 89
IV.FAEN.HNZ. 2018-04-21T02:47:12.84 0.6 undecidable manual P 80 14.1747 142 -0.25 49
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.BRIS.HHE. ML:1.9 0.000577945 0.1808 AML other m 2018-04-21T02:47:15.38
IV.BRIS.HNE. ML:1.9 0.0006270819 0.24 AML other m 2018-04-21T02:47:15.39
IV.BRIS.HHN. ML:2.0 0.0006640544500000001 0.28 AML other m 2018-04-21T02:47:15.55
IV.BRIS.HNN. ML:1.9 0.00054821975 0.2304 AML other m 2018-04-21T02:47:15.54
IV.IMOL.HNE. ML:2.2 0.00119242625 0.1808 AML other m 2018-04-21T02:47:16.60
IV.IMOL.HNN. ML:2.1 0.0008258392 0.32 AML other m 2018-04-21T02:47:16.85
IV.MTRZ.HNN. ML:1.7 0.0002369032 0.52 AML other m 2018-04-21T02:47:20.28
IV.MTRZ.HHN. ML:1.7 0.00024044135 0.52 AML other m 2018-04-21T02:47:20.02
IV.SEI.HHN. ML:2.3 0.0006728238 1.6608 AML other m 2018-04-21T02:47:21.99
IV.ASQU.HHE. ML:1.5 0.00006914052500000001 0.5792 AML other m 2018-04-21T02:47:26.74
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