Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 23-10-2021 and time 02:04:11 (Italy) in region 2 km W Accumoli (RI)

A magnitude ML 1.1 earthquake occured in region: 2 km W Accumoli (RI), on

  • 23-10-2021 00:04:11 (UTC)
  • 23-10-2021 02:04:11 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7050, 13.2220 at 13 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.

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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
Accumoli RI 2 667 667
Arquata del Tronto AP 10 1178 1845
Amatrice RI 10 2657 4502
Cittareale RI 11 482 4984
Norcia PG 14 4957 9941
Acquasanta Terme AP 17 2916 12857
Cascia PG 17 3217 16074
Montegallo AP 18 523 16597

Municipalities with at least 50000 inhabitants

An earthquake occurred to
40 Km W of Teramo (54892 inhabitants)
42 Km NW of L'Aquila (69753 inhabitants)
50 Km E of Terni (111501 inhabitants)
51 Km SE of Foligno (57155 inhabitants)
79 Km W of Montesilvano (53738 inhabitants)
81 Km SE of Perugia (166134 inhabitants)
86 Km W of Pescara (121014 inhabitants)
87 Km W of Chieti (51815 inhabitants)
88 Km NE of Guidonia Montecelio (88673 inhabitants)
89 Km NE of Tivoli (56533 inhabitants)
97 Km E of Viterbo (67173 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 2021-10-23
00:04:11		 42.7047 13.2223 13 2021-10-23
00:10:18		 Sala Sismica INGV-Roma 96892921
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-10-23 00:04:11 ± 0.06
Latitude 42.7047 ± 0.0027
Longitude 13.2223 ± 0.0037
Depth (km) 13 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 96892921

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 290
Semi-minor axis of confidence ellipse (meter) 99
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 88
Circular confidence region, given by single value of horizontal uncertainty (meter) 290.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 85
Number of associated phases, regardless of their use for origin computation 19
Number of defining phases 18
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.11
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.38671
Number of stations at which the event was observed 10
Number of stations from which data was used for origin computation 9
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.4
Num. used stations 5
Type of magnitude ML
Reference to an origin 96892921
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-10-23 00:10:18
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SRES.HHZ. 2021-10-23T00:04:33.51 3.0 undecidable manual S -3.4 0
IV.CSP1.EHZ. 2021-10-23T00:04:26.10 0.6 undecidable manual S 358 42.9237 94 0.28 46
IV.TERO.HHZ. 2021-10-23T00:04:22.74 0.6 undecidable manual S 106 32.4453 95 -0.28 47
IV.GAVE.HNE. 2021-10-23T00:04:21.53 0.6 undecidable manual S 267 26.751 98 0.01 50
IV.MMO1.EHZ. 2021-10-23T00:04:20.55 0.6 undecidable manual S 21 23.1546 100 -0.02 50
IV.RM33.EHZ. 2021-10-23T00:04:20.09 0.6 undecidable manual S 182 21.7671 101 -0.09 49
IV.CSP1.EHZ. 2021-10-23T00:04:19.99 1.0 negative manual P 358 42.9237 94 0.06 24
IV.LNSS.HHN. 2021-10-23T00:04:19.28 0.6 undecidable manual S 233 18.6702 106 -0.11 49
IV.NRCA.HHZ. 2021-10-23T00:04:18.56 0.6 undecidable manual S 328 16.7721 110 -0.35 47
IV.TERO.HHZ. 2021-10-23T00:04:18.24 0.6 positive manual P 106 32.4453 95 -0.07 49
IV.T1299.EHN. 2021-10-23T00:04:17.12 0.6 undecidable manual S 148 9.1797 134 -0.07 50
IV.GAVE.HNE. 2021-10-23T00:04:17.54 0.1 undecidable manual P 267 26.751 98 0.1 98
IV.SMA1.EHZ. 2021-10-23T00:04:17.91 0.6 undecidable manual S 132 12.3765 122 0.06 51
IV.RM33.EHZ. 2021-10-23T00:04:16.71 0.6 negative manual P 182 21.7671 101 0.04 50
IV.MMO1.EHZ. 2021-10-23T00:04:16.92 0.6 positive manual P 21 23.1546 100 0.02 50
IV.LNSS.HHN. 2021-10-23T00:04:16.26 0.1 undecidable manual P 233 18.6702 106 0.05 100
IV.NRCA.HHZ. 2021-10-23T00:04:15.87 0.1 undecidable manual P 328 16.7721 110 -0.07 100
IV.T1299.EHN. 2021-10-23T00:04:15.09 0.1 undecidable manual P 148 9.1797 134 0.14 100
IV.SMA1.EHZ. 2021-10-23T00:04:15.41 0.6 negative manual P 132 12.3765 122 0.08 50
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.NRCA.HHN. ML:1.3 0.00016299999999999998 0.08 AML other m 2021-10-23T00:04:18.66
IV.NRCA.HHE. ML:1.4 0.0001735 0.48 AML other m 2021-10-23T00:04:18.86
IV.SMA1.EHE. ML:0.3 0.0000214038 0.12 AML other m 2021-10-23T00:04:18.34
IV.SMA1.EHN. ML:0.4 0.000026936350000000002 0.12 AML other m 2021-10-23T00:04:18.55
IV.NRCA.HNE. ML:1.3 0.00014456424 0.08 AML other m 2021-10-23T00:04:18.86
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