Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.1 on date 03-08-2021 and time 11:13:55 (Italy) in region 1 km SW Norcia (PG)

A magnitude ML 1.1 earthquake occured in region: 1 km SW Norcia (PG), on

  • 03-08-2021 09:13:55 (UTC)
  • 03-08-2021 11:13:55 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7860, 13.0850 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
Norcia PG 1 4957 4957
Cascia PG 9 3217 8174
Preci PG 11 724 8898
Castelsantangelo sul Nera MC 13 281 9179
Cerreto di Spoleto PG 14 1075 10254
Poggiodomo PG 15 117 10371
Visso MC 16 1107 11478
Accumoli RI 17 667 12145
Sellano PG 17 1079 13224
Arquata del Tronto AP 17 1178 14402
Vallo di Nera PG 18 364 14766
Ussita MC 18 444 15210
Monteleone di Spoleto PG 18 599 15809
Cittareale RI 20 482 16291

Municipalities with at least 50000 inhabitants

An earthquake occurred to
36 Km SE of Foligno (57155 inhabitants)
44 Km NE of Terni (111501 inhabitants)
53 Km W of Teramo (54892 inhabitants)
55 Km NW of L'Aquila (69753 inhabitants)
67 Km SE of Perugia (166134 inhabitants)
90 Km E of Viterbo (67173 inhabitants)
92 Km NE of Guidonia Montecelio (88673 inhabitants)
92 Km W of Montesilvano (53738 inhabitants)
94 Km N of Tivoli (56533 inhabitants)
99 Km W of Pescara (121014 inhabitants)
99 Km SW of Ancona (100861 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 2021-08-03
09:13:55		 42.7857 13.0848 10 2021-08-03
09:30:45		 Sala Sismica INGV-Roma 93602631
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-03 09:13:55 ± 0.09
Latitude 42.7857 ± 0.0027
Longitude 13.0848 ± 0.0049
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 93602631

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 437
Semi-minor axis of confidence ellipse (meter) 195
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 118
Circular confidence region, given by single value of horizontal uncertainty (meter) 440.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 159
Number of associated phases, regardless of their use for origin computation 9
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.08
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.18526
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 4
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.3
Num. used stations 14
Type of magnitude ML
Reference to an origin 93602631
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-03 09:30:45
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.LNSS.HHZ. 2021-08-03T09:14:03.30 0.3 undecidable manual S 190 20.5683 116 0.08 73
IV.ARRO.EHZ. 2021-08-03T09:14:02.44 3.0 undecidable manual P 0 0
IV.GAVE.EHZ. 2021-08-03T09:14:02.59 0.3 undecidable manual S 236 18.6702 118 -0.04 73
IV.MC2.EHZ. 2021-08-03T09:14:01.99 0.3 undecidable manual S 31 16.3725 121 0.07 73
IV.LNSS.HHZ. 2021-08-03T09:13:59.78 0.1 undecidable manual P 190 20.5683 116 -0.09 97
IV.NRCA.HHZ. 2021-08-03T09:13:59.23 0.3 undecidable manual S 24 5.7942 150 -0.06 75
IV.GAVE.EHZ. 2021-08-03T09:13:59.59 0.1 undecidable manual P 236 18.6702 118 0.06 97
IV.MC2.EHZ. 2021-08-03T09:13:59.07 0.1 undecidable manual P 31 16.3725 121 -0.05 98
IV.NRCA.HHZ. 2021-08-03T09:13:57.64 0.1 undecidable manual P 24 5.7942 150 0.04 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.NRCA.HHN. ML:1.3 0.0002915 0.08 AML other m 2021-08-03T09:13:59.27
IV.NRCA.HHE. ML:1.4 0.00035999999999999997 0.1 AML other m 2021-08-03T09:13:59.40
IV.LNSS.HHE. ML:0.5 0.000026830340000000002 0.16 AML other m 2021-08-03T09:14:03.64
IV.LNSS.HHN. ML:0.7 0.00003685 0.1 AML other m 2021-08-03T09:14:03.69
IV.NRCA.HNE. ML:1.3 0.00032463910000000003 0.1088 AML other m 2021-08-03T09:13:59.41
IV.NRCA.HNN. ML:1.2 0.00027647175 0.0832 AML other m 2021-08-03T09:13:59.27
IV.GAVE.EHE. ML:0.8 0.000044663851499999995 0.2432 AML other m 2021-08-03T09:14:03.66
IV.GAVE.EHN. ML:0.9 0.000058269375 0.224 AML other m 2021-08-03T09:14:02.93
IV.GAVE.HNE. ML:1.1 0.000095629705 0.8704 AML other m 2021-08-03T09:14:07.02
IV.GAVE.HNN. ML:1.4 0.00020797210000000001 0.8576 AML other m 2021-08-03T09:13:59.79
IV.LNSS.HNE. ML:2.1 0.0010454906 1.1712 AML other m 2021-08-03T09:14:08.11
IV.LNSS.HNN. ML:1.6 0.00026669409999999997 0.9408 AML other m 2021-08-03T09:14:04.48
IV.ARRO.EHE. ML:1.0 0.000046912455000000006 0.0576 AML other m 2021-08-03T09:14:03.53
IV.ARRO.EHN. ML:0.9 0.00003163297 0.1216 AML other m 2021-08-03T09:14:03.16
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