Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 20-10-2021 and time 17:53:39 (UTC) in region 6 km N Posta (RI)

A magnitude ML 1.1 earthquake occured in region: 6 km N Posta (RI), on

  • 20-10-2021 17:53:39 (UTC)
  • 20-10-2021 19:53:39 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.5740, 13.1100 at 15 km depth.

The earthquake was located by: Sala Sismica INGV-Roma.

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.

Hai sentito il terremoto? Clicca qui

Did you feel it? Fill in the questionnaire.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Posta RI 6 694 694
Cittareale RI 6 482 1176
Borbona RI 7 617 1793
Leonessa RI 12 2435 4228
Montereale AQ 12 2581 6809
Micigliano RI 14 127 6936
Monteleone di Spoleto PG 16 599 7535
Cagnano Amiterno AQ 16 1369 8904
Amatrice RI 16 2657 11561
Capitignano AQ 17 665 12226
Antrodoco RI 18 2588 14814
Accumoli RI 18 667 15481
Cascia PG 18 3217 18698
Borgo Velino RI 19 972 19670
Barete AQ 20 737 20407
Poggio Bustone RI 20 2055 22462

Municipalities with at least 50000 inhabitants

An earthquake occurred to
34 Km NW of L'Aquila (69753 inhabitants)
38 Km E of Terni (111501 inhabitants)
50 Km W of Teramo (54892 inhabitants)
54 Km SE of Foligno (57155 inhabitants)
71 Km NE of Guidonia Montecelio (88673 inhabitants)
73 Km NE of Tivoli (56533 inhabitants)
84 Km SE of Perugia (166134 inhabitants)
84 Km E of Viterbo (67173 inhabitants)
86 Km W of Montesilvano (53738 inhabitants)
90 Km W of Chieti (51815 inhabitants)
91 Km W of Pescara (121014 inhabitants)
92 Km NE of Roma (2864731 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
Reviewed
Rev100 		ML 1.1 2021-10-20
17:53:39		 42.5745 13.1098 15 2021-10-20
17:57:39		 Sala Sismica INGV-Roma 96806171
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-10-20 17:53:39 ± 0.12
Latitude 42.5745 ± 0.0054
Longitude 13.1098 ± 0.0049
Depth (km) 15 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 96806171

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 489
Semi-minor axis of confidence ellipse (meter) 401
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 360
Circular confidence region, given by single value of horizontal uncertainty (meter) 490.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 141
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 13
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) 0.05846
Epicentral distance of station farthest from the epicenter (degree) 0.36692
Number of stations at which the event was observed 7
Number of stations from which data was used for origin computation 7
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 12
Type of magnitude ML
Reference to an origin 96806171
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-10-20 17:57:39
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.TERO.HHZ. 2021-10-20T17:53:52.54 0.6 undecidable manual S 82 40.7259 97 -0.32 45
IV.ARRO.EHZ. 2021-10-20T17:53:49.27 0.6 undecidable manual S 271 28.1496 103 -0.28 46
IV.NRCA.HHZ. 2021-10-20T17:53:49.65 0.6 undecidable manual S 1 28.749 102 -0.07 48
IV.TERO.HHZ. 2021-10-20T17:53:47.13 0.6 negative manual P 82 40.7259 97 -0.08 47
IV.SMA1.EHZ. 2021-10-20T17:53:47.19 0.6 undecidable manual S 71 19.4694 113 -0.15 48
IV.ARRO.EHZ. 2021-10-20T17:53:45.27 0.6 positive manual P 271 28.1496 103 -0.03 49
IV.NRCA.HHZ. 2021-10-20T17:53:45.38 0.6 negative manual P 1 28.749 102 -0.01 49
IV.RM33.EHZ. 2021-10-20T17:53:45.36 0.6 undecidable manual S 130 11.1777 133 -0.14 49
IV.SMA1.EHZ. 2021-10-20T17:53:44.28 0.1 positive manual P 71 19.4694 113 0.26 94
IV.LNSS.HHZ. 2021-10-20T17:53:44.71 0.6 undecidable manual S 299 6.4935 151 -0.01 50
IV.GAVE.EHZ. 2021-10-20T17:53:44.46 0.3 undecidable manual P 307 21.9669 109 0.09 73
IV.RM33.EHZ. 2021-10-20T17:53:43.08 0.1 negative manual P 130 11.1777 133 0.12 98
IV.LNSS.HHZ. 2021-10-20T17:53:42.59 0.1 undecidable manual P 299 6.4935 151 0.08 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.LNSS.HHE. ML:1.3 0.00022499999999999997 0.32 AML other m 2021-10-20T17:53:44.82
IV.LNSS.HHN. ML:1.1 0.0001255 1.7 AML other m 2021-10-20T17:53:44.03
IV.RM33.EHE. ML:1.0 0.000092 1.16 AML other m 2021-10-20T17:53:45.80
IV.RM33.EHN. ML:1.1 0.0001185 0.78 AML other m 2021-10-20T17:53:45.97
IV.SMA1.EHN. ML:0.9 0.0000558 0.22 AML other m 2021-10-20T17:53:47.99
IV.SMA1.EHE. ML:1.3 0.000136 0.46 AML other m 2021-10-20T17:53:48.00
IV.NRCA.HHN. ML:1.1 0.000057300000000000004 0.1 AML other m 2021-10-20T17:53:50.31
IV.ARRO.EHN. ML:0.9 0.00004075 1.42 AML other m 2021-10-20T17:53:50.77
IV.NRCA.HHE. ML:1.3 0.00008465 1.9 AML other m 2021-10-20T17:53:50.04
IV.ARRO.EHE. ML:0.7 0.000024499999999999996 1.52 AML other m 2021-10-20T17:53:51.13
IV.GAVE.EHN. ML:1.1 0.00007694999999999999 0.5 AML other m 2021-10-20T17:53:54.72
IV.GAVE.EHE. ML:1.0 0.00005865 0.16 AML other m 2021-10-20T17:53:54.64
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