Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 23-07-2021 and time 11:22:02 (UTC) in region 1 km NW Accumoli (RI)

A magnitude ML 1.1 earthquake occured in region: 1 km NW Accumoli (RI), on

  • 23-07-2021 11:22:02 (UTC)
  • 23-07-2021 13:22:02 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7020, 13.2400 at 10 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 1 667 667
Amatrice RI 9 2657 3324
Arquata del Tronto AP 9 1178 4502
Cittareale RI 11 482 4984
Norcia PG 16 4957 9941
Acquasanta Terme AP 16 2916 12857
Montegallo AP 18 523 13380
Cascia PG 19 3217 16597
Campotosto AQ 19 542 17139
Montereale AQ 20 2581 19720

Municipalities with at least 50000 inhabitants

An earthquake occurred to
38 Km W of Teramo (54892 inhabitants)
41 Km NW of L'Aquila (69753 inhabitants)
51 Km E of Terni (111501 inhabitants)
52 Km SE of Foligno (57155 inhabitants)
77 Km W of Montesilvano (53738 inhabitants)
83 Km SE of Perugia (166134 inhabitants)
84 Km W of Pescara (121014 inhabitants)
85 Km W of Chieti (51815 inhabitants)
89 Km NE of Guidonia Montecelio (88673 inhabitants)
90 Km NE of Tivoli (56533 inhabitants)
98 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 2021-07-23
11:22:02		 42.7018 13.24 11 2021-07-23
11:40:52		 Sala Sismica INGV-Roma 93104171
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-07-23 11:22:02 ± 0.06
Latitude 42.7018 ± 0.0036
Longitude 13.2400 ± 0.0049
Depth (km) 11 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 93104171

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 389
Semi-minor axis of confidence ellipse (meter) 348
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 85
Circular confidence region, given by single value of horizontal uncertainty (meter) 390.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 89
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.63492
Number of stations at which the event was observed 13
Number of stations from which data was used for origin computation 11
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 93104171
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-07-23 11:40:52
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.RIBO.EHZ.01 2021-07-23T11:22:31.34 3.0 undecidable manual Pn -0.03 0
IV.EL6.EHZ. 2021-07-23T11:22:15.46 0.3 undecidable manual P 351 70.4739 50 0.45 62
IV.MML1.EHZ. 2021-07-23T11:22:11.01 3.0 negative manual P -1.22 0
IV.MF5.EHZ. 2021-07-23T11:22:10.11 0.1 undecidable manual P 29 36.4413 50 0.35 90
IV.CSP1.EHZ. 2021-07-23T11:22:10.73 0.1 undecidable manual P 356 43.3233 50 -0.1 94
IV.LNSS.HHZ. 2021-07-23T11:22:10.45 0.1 undecidable manual S 236 19.6692 118 0.06 99
IV.FDMO.HHZ. 2021-07-23T11:22:09.99 0.1 undecidable manual P 342 39.1275 50 -0.19 93
IV.NRCA.HHZ. 2021-07-23T11:22:09.74 0.1 undecidable manual S 325 17.871 121 -0.1 98
IV.SMA1.EHZ. 2021-07-23T11:22:08.05 0.1 undecidable manual S 135 11.0778 133 0.09 100
IV.MTRA.EHZ. 2021-07-23T11:22:08.62 0.1 undecidable manual S 64 14.1747 127 -0.15 98
IV.TERO.HHZ. 2021-07-23T11:22:08.61 0.1 undecidable manual P 106 30.9468 50 -0.31 92
IV.MC2.EHZ. 2021-07-23T11:22:07.76 0.1 undecidable manual P 350 23.6541 50 -0.03 99
IV.LNSS.HHZ. 2021-07-23T11:22:07.06 0.1 undecidable manual P 236 19.6692 118 -0.06 99
IV.RM33.EHZ. 2021-07-23T11:22:07.33 0.1 undecidable manual P 186 21.4674 116 -0.12 97
IV.NRCA.HHZ. 2021-07-23T11:22:06.84 0.1 undecidable manual P 325 17.871 121 0.04 100
IV.MTRA.EHZ. 2021-07-23T11:22:06.23 0.1 undecidable manual P 64 14.1747 127 0.05 100
IV.SMA1.EHZ. 2021-07-23T11:22:05.91 0.1 undecidable manual P 135 11.0778 133 0.19 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.SMA1.EHN. ML:1.3 0.0002235 0.16 AML other m 2021-07-23T11:22:08.13
IV.SMA1.EHE. ML:1.2 0.000175 0.38 AML other m 2021-07-23T11:22:08.20
IV.MTRA.EHN. ML:1.4 0.000268 0.14 AML other m 2021-07-23T11:22:08.76
IV.MTRA.EHE. ML:1.2 0.000177 0.24 AML other m 2021-07-23T11:22:09.35
IV.LNSS.HHE. ML:1.0 0.00006785 0.26 AML other m 2021-07-23T11:22:10.61
IV.RM33.EHE. ML:1.2 0.00011545 0.86 AML other m 2021-07-23T11:22:11.45
IV.RM33.EHN. ML:1.1 0.00009109999999999999 1.02 AML other m 2021-07-23T11:22:11.97
IV.LNSS.HHN. ML:1.0 0.00006829999999999999 0.48 AML other m 2021-07-23T11:22:11.70
IV.FDMO.HHN. ML:0.8 0.000019799999999999997 1.68 AML other m 2021-07-23T11:22:15.06
IV.FDMO.HHE. ML:0.8 0.0000204 0.9 AML other m 2021-07-23T11:22:18.20
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