Earthquake with magnitude of ML 1.0 on date 20-04-2021 and time 16:10:42 (Italy) in region 1 km SW Polino (TR)

A magnitude ML 1.0 earthquake occured in region: 1 km SW Polino (TR), on

  • 20-04-2021 14:10:42 (UTC)
  • 20-04-2021 16:10:42 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.574, 12.839 at 14 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Polino TR 1 233 233
Morro Reatino RI 5 373 606
Arrone TR 6 2763 3369
Labro RI 6 374 3743
Montefranco TR 6 1276 5019
Rivodutri RI 7 1253 6272
Ferentillo TR 7 1913 8185
Poggio Bustone RI 9 2055 10240
Colli sul Velino RI 10 533 10773
Leonessa RI 10 2435 13208
Monteleone di Spoleto PG 13 599 13807
Cantalice RI 13 2755 16562
Greccio RI 15 1558 18120
Scheggino PG 16 461 18581
Terni TR 16 111501 130082
Stroncone TR 17 4917 134999
Poggiodomo PG 17 117 135116
Sant'Anatolia di Narco PG 18 564 135680
Rieti RI 19 47698 183378
Contigliano RI 19 3783 187161
Spoleto PG 20 38218 225379

Municipalities with at least 50000 inhabitants

An earthquake occurred to
16 Km E of Terni (111501 inhabitants)
44 Km S of Foligno (57155 inhabitants)
52 Km W of L'Aquila (69753 inhabitants)
63 Km E of Viterbo (67173 inhabitants)
64 Km N of Guidonia Montecelio (88673 inhabitants)
68 Km N of Tivoli (56533 inhabitants)
70 Km SE of Perugia (166134 inhabitants)
72 Km W of Teramo (54892 inhabitants)
81 Km NE of Roma (2864731 inhabitants)
99 Km N of Velletri (53303 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 2021-04-20
14:10:42
42.5743 12.8393 14 2021-07-12
16:55:16
Bollettino Sismico Italiano INGV 91700281
Reviewed
Rev100
ML 1.0 2021-04-20
14:10:41
42.5492 12.8373 11 2021-04-20
14:16:07
Sala Sismica INGV-Roma 89295831
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-04-20 14:10:42 ± 0.07
Latitude 42.5743 ± 0.0045
Longitude 12.8393 ± 0.0037
Depth (km) 14 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 91700281

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 474
Semi-minor axis of confidence ellipse (meter) 106
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 181
Circular confidence region, given by single value of horizontal uncertainty (meter) 470
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 172
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.15
Epicentral distance of station closest to the epicenter (degree) 0
Epicentral distance of station farthest from the epicenter (degree) 0.49643
Number of stations at which the event was observed 9
Number of stations from which data was used for origin computation 7
Magnitudes information

ML:1

Field Value
Value 1
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 91700281
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-06-22 09:21:05

ML:1

Field Value
Value 1
Uncertainty 0.3
Num. used stations 10
Type of magnitude ML
Reference to an origin 89295831
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-04-20 14:16:07
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.VIVA.HHZ. 2021-04-20T14:11:09.11 3.0 undecidable manual S -0.08 0
IV.FAGN.HHZ. 2021-04-20T14:11:04.22 3.0 undecidable manual S 0.35 0
IV.FDMO.HHZ. 2021-04-20T14:10:59.49 0.3 undecidable manual S 21 0.4964 94 0.16 68
IV.RM33.HNE. 2021-04-20T14:10:53.46 0.6 undecidable manual S 103 0.2842 99 0.39 45
IV.MOMA.HHZ. 2021-04-20T14:10:53.81 0.3 undecidable manual S 319 0.3031 98 0.18 70
IV.FDMO.HHZ. 2021-04-20T14:10:51.83 0.1 undecidable manual P 21 0.4964 94 -0.24 90
IV.CESX.HHZ. 2021-04-20T14:10:50.28 0.3 undecidable manual S 280 0.1889 107 -0.04 74
IV.LNSS.HHZ. 2021-04-20T14:10:49.21 0.3 undecidable manual S 79 0.1502 115 -0.05 74
IV.RM33.HNE. 2021-04-20T14:10:48.38 0.1 undecidable manual P 103 0.2842 99 -0.07 96
IV.GAVE.EHZ. 2021-04-20T14:10:48.37 0.6 undecidable manual S 19 0.1241 123 -0.21 48
IV.MOMA.HHZ. 2021-04-20T14:10:48.81 0.1 undecidable manual P 319 0.3031 98 0.04 96
IV.ARRO.EHZ. 2021-04-20T14:10:47.18 0.6 undecidable manual S 275 0.054 151 0.03 51
IV.LNSS.HHZ. 2021-04-20T14:10:46.25 0.1 negative manual P 79 0.1502 115 0 100
IV.CESX.HHZ. 2021-04-20T14:10:46.83 0.1 undecidable manual P 280 0.1889 107 -0.04 99
IV.GAVE.EHZ. 2021-04-20T14:10:45.81 0.1 undecidable manual P 19 0.1241 123 -0.05 100
IV.ARRO.EHZ. 2021-04-20T14:10:45.27 0.3 undecidable manual P 275 0.054 151 0.23 73
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ARRO.EHN. ML:0.7 5.74E-5 0.14 AML other m 2021-04-20T14:10:47.71
IV.ARRO.EHE. ML:0.9 9.175E-5 0.2 AML other m 2021-04-20T14:10:48.28
IV.GAVE.EHN. ML:1.4 0.0001945 0.36 AML other m 2021-04-20T14:10:48.83
IV.GAVE.EHE. ML:1.2 0.000154 0.86 AML other m 2021-04-20T14:10:49.63
IV.LNSS.HHE. ML:1.1 0.0001045 0.36 AML other m 2021-04-20T14:10:49.73
IV.CESX.HHN. ML:0.8 4.235E-5 0.3 AML other m 2021-04-20T14:10:50.63
IV.LNSS.HHN. ML:1.1 0.0001039 0.88 AML other m 2021-04-20T14:10:50.67
IV.CESX.HHE. ML:0.8 4.09E-5 0.24 AML other m 2021-04-20T14:10:51.82
IV.MOMA.HHN. ML:1.2 6.37E-5 0.26 AML other m 2021-04-20T14:10:54.20
IV.MOMA.HHE. ML:1.1 4.79E-5 1.54 AML other m 2021-04-20T14:10:55.17
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
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QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download