Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 16-08-2021 and time 21:42:23 (Italy) in region 4 km E Villavallelonga (AQ)

A magnitude ML 1.1 earthquake occured in region: 4 km E Villavallelonga (AQ), on

  • 16-08-2021 19:42:23 (UTC)
  • 16-08-2021 21:42:23 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 41.8860, 13.6710 at 12 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
Villavallelonga AQ 4 919 919
Lecce nei Marsi AQ 6 1702 2621
Collelongo AQ 7 1233 3854
Gioia dei Marsi AQ 8 1989 5843
Ortucchio AQ 8 1860 7703
Bisegna AQ 8 223 7926
Balsorano AQ 13 3569 11495
Pescasseroli AQ 13 2203 13698
San Vincenzo Valle Roveto AQ 13 2347 16045
Ortona dei Marsi AQ 14 542 16587
Trasacco AQ 14 6246 22833
San Benedetto dei Marsi AQ 14 3909 26742
Villalago AQ 15 568 27310
Pescosolido FR 15 1555 28865
Pescina AQ 16 4133 32998
Campoli Appennino FR 16 1725 34723
Civita d'Antino AQ 16 979 35702
Anversa degli Abruzzi AQ 17 341 36043
Scanno AQ 18 1847 37890
Opi AQ 18 420 38310
Morino AQ 18 1448 39758
Cocullo AQ 19 230 39988
Luco dei Marsi AQ 19 6079 46067
Sora FR 19 26144 72211
Collarmele AQ 20 894 73105

Municipalities with at least 50000 inhabitants

An earthquake occurred to
57 Km SE of L'Aquila (69753 inhabitants)
66 Km SW of Chieti (51815 inhabitants)
73 Km E of Tivoli (56533 inhabitants)
77 Km E of Velletri (53303 inhabitants)
79 Km SW of Pescara (121014 inhabitants)
79 Km NE of Latina (125985 inhabitants)
79 Km E of Guidonia Montecelio (88673 inhabitants)
80 Km SW of Montesilvano (53738 inhabitants)
86 Km S of Teramo (54892 inhabitants)
91 Km E of Aprilia (73446 inhabitants)
98 Km E of Roma (2864731 inhabitants)
99 Km NE of Anzio (54211 inhabitants)
100 Km E of Pomezia (62966 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 1.1 2021-08-16
19:42:23		 41.8858 13.6707 12 2021-12-29
11:12:22		 Bollettino Sismico Italiano INGV 94614251
Reviewed
Rev100 		ML 0.9 2021-08-16
19:42:23		 41.8847 13.6698 12 2021-08-16
19:53:53		 Sala Sismica INGV-Roma 94269191
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-16 19:42:23 ± 0.07
Latitude 41.8858 ± 0.0036
Longitude 13.6707 ± 0.0048
Depth (km) 12 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 94614251

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 373
Semi-minor axis of confidence ellipse (meter) 290
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 55
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) 79
Number of associated phases, regardless of their use for origin computation 28
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.19
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.38761
Number of stations at which the event was observed 22
Number of stations from which data was used for origin computation 8
Magnitudes information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 6
Type of magnitude ML
Reference to an origin 94614251
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-09-01 12:02:28

ML:0.9

Field Value
Value 0.9
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 94269191
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-16 19:53:53
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.RRL.HHZ. 2021-08-16T19:44:01.84 3.0 undecidable manual Pg 15.83 0
IV.SPS2.HHZ. 2021-08-16T19:43:53.89 3.0 undecidable manual Sn -5.79 0
IV.ORI.HHZ. 2021-08-16T19:43:51.56 3.0 undecidable manual Sg 3.93 0
IV.ESCV.HHZ. 2021-08-16T19:43:42.06 3.0 positive manual Pg 13.31 0
AC.VLO.HHZ. 2021-08-16T19:43:40.70 3.0 negative manual Pn 5.78 0
IV.PLAC.HHZ. 2021-08-16T19:43:34.45 3.0 undecidable manual Pg 7.74 0
ST.GAGG.HHZ. 2021-08-16T19:43:31.40 3.0 undecidable manual Pn 1.8 0
IV.OSSC.HHZ. 2021-08-16T19:43:29.11 3.0 undecidable manual Sg 1.11 0
IX.PGN3.HHZ.02 2021-08-16T19:43:26.49 3.0 undecidable manual Sn -3.59 0
IV.MCRV.HHZ. 2021-08-16T19:43:18.03 3.0 undecidable manual Sg 0.12 0
IX.NSC3.EHZ.02 2021-08-16T19:43:13.67 3.0 undecidable manual Sn -2.55 0
IV.CMIS.HHZ. 2021-08-16T19:43:06.69 3.0 undecidable manual S 0.26 0
IX.SCL3.EHZ.02 2021-08-16T19:43:00.07 3.0 positive manual Pg 3.42 0
IT.RMMM.HGZ. 2021-08-16T19:42:34.89 3.0 positive manual P -1.88 0
IV.LRP.EHZ. 2021-08-16T19:42:33.28 0.3 undecidable manual S 195 27.3504 94 -0.26 69
IV.PTQR.HHZ. 2021-08-16T19:42:33.48 0.3 undecidable manual S 304 26.9508 94 0.06 72
IV.INTR.HHZ. 2021-08-16T19:42:32.34 0.1 undecidable manual S 54 23.8539 95 -0.25 94
IT.OPI.HGZ. 2021-08-16T19:42:31.11 0.1 undecidable manual S 133 17.9709 101 0.07 98
IV.CERA.HNE. 2021-08-16T19:42:31.56 0.3 undecidable manual P 138 43.0236 92 -0.25 67
IV.POFI.HHE. 2021-08-16T19:42:31.17 0.1 undecidable manual S 170 18.9699 99 -0.14 96
IV.T0110.HHZ. 2021-08-16T19:42:31.25 0.3 undecidable manual P 13 39.1275 92 0.04 71
IV.LRP.EHZ. 2021-08-16T19:42:29.48 0.1 undecidable manual P 195 27.3504 94 0.07 97
IV.PTQR.HHZ. 2021-08-16T19:42:29.26 0.1 undecidable manual P 304 26.9508 94 -0.08 96
IV.VVLD.HHZ. 2021-08-16T19:42:28.02 0.1 undecidable manual S 245 4.2957 155 -0.09 100
IT.OPI.HGZ. 2021-08-16T19:42:28.26 0.1 undecidable manual P 133 17.9709 101 0.29 94
IV.INTR.HHZ. 2021-08-16T19:42:28.85 0.1 undecidable manual P 54 23.8539 95 -0.01 98
IV.POFI.HHE. 2021-08-16T19:42:28.37 0.1 undecidable manual P 170 18.9699 99 0.24 95
IV.VVLD.HHZ. 2021-08-16T19:42:26.46 0.1 positive manual P 245 4.2957 155 0.18 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VVLD.HHE. ML:1.4 0.000352 0.12 AML other m 2021-08-16T19:42:28.12
IV.VVLD.HHN. ML:1.1 0.00016700000000000002 0.16 AML other m 2021-08-16T19:42:28.20
IV.VVLD.HNN. ML:1.0 0.000138207625 0.1408 AML other m 2021-08-16T19:42:28.19
IV.VVLD.HNE. ML:1.3 0.0003105006 0.128 AML other m 2021-08-16T19:42:28.12
IV.INTR.HHN. ML:0.8 0.000035872071 0.1408 AML other m 2021-08-16T19:42:32.83
IV.INTR.HHE. ML:0.8 0.00003864304 0.1152 AML other m 2021-08-16T19:42:32.81
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