Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 31-10-2021 and time 08:50:04 (Italy) in region 6 km E Cerreto di Spoleto (PG)

A magnitude ML 1.0 earthquake occured in region: 6 km E Cerreto di Spoleto (PG), on

  • 31-10-2021 07:50:04 (UTC)
  • 31-10-2021 08:50:04 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.8100, 12.9870 at 11 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
Cerreto di Spoleto PG 6 1075 1075
Preci PG 9 724 1799
Norcia PG 9 4957 6756
Sellano PG 10 1079 7835
Cascia PG 10 3217 11052
Vallo di Nera PG 11 364 11416
Poggiodomo PG 12 117 11533
Sant'Anatolia di Narco PG 15 564 12097
Visso MC 16 1107 13204
Scheggino PG 17 461 13665
Castelsantangelo sul Nera MC 17 281 13946
Campello sul Clitunno PG 17 2442 16388
Monteleone di Spoleto PG 18 599 16987
Ussita MC 20 444 17431

Municipalities with at least 50000 inhabitants

An earthquake occurred to
28 Km SE of Foligno (57155 inhabitants)
39 Km NE of Terni (111501 inhabitants)
59 Km SE of Perugia (166134 inhabitants)
61 Km W of Teramo (54892 inhabitants)
61 Km NW of L'Aquila (69753 inhabitants)
84 Km NE of Viterbo (67173 inhabitants)
93 Km N of Guidonia Montecelio (88673 inhabitants)
95 Km N of Tivoli (56533 inhabitants)
100 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 1.0 2021-10-31
07:50:04		 42.8102 12.9873 11 2021-10-31
08:01:00		 Sala Sismica INGV-Roma 97105341
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-10-31 07:50:04 ± 0.09
Latitude 42.8102 ± 0.0054
Longitude 12.9873 ± 0.0098
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 97105341

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 919
Semi-minor axis of confidence ellipse (meter) 314
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 120
Circular confidence region, given by single value of horizontal uncertainty (meter) 920.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 168
Number of associated phases, regardless of their use for origin computation 16
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.22
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.32376
Number of stations at which the event was observed 9
Number of stations from which data was used for origin computation 7
Magnitude information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 97105341
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-10-31 08:01:00
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.SACS.HHZ. 2021-10-31T07:50:20.92 3.0 undecidable manual P 0.59 0
IV.CSP1.EHZ. 2021-10-31T07:50:17.21 0.3 undecidable manual S 29 35.9418 50 0.19 71
IV.MMO1.EHZ. 2021-10-31T07:50:15.24 0.6 undecidable manual S 70 29.3484 50 -0.03 49
IV.FDMO.HHZ. 2021-10-31T07:50:14.33 0.1 undecidable manual S 18 26.3514 50 -0.16 97
IV.MC2.EHZ. 2021-10-31T07:50:13.57 0.6 undecidable manual S 55 19.869 118 0.88 39
IV.LNSS.HHZ. 2021-10-31T07:50:13.73 0.6 undecidable manual S 169 23.3544 50 0.05 50
IV.CESI.HHZ. 2021-10-31T07:50:12.43 3.0 undecidable manual S -0.15 0
IV.GAVE.EHZ. 2021-10-31T07:50:11.32 0.3 undecidable manual S 210 15.0738 125 0.04 76
IV.CSP1.EHZ. 2021-10-31T07:50:11.90 0.1 undecidable manual P 29 35.9418 50 0.01 98
IV.FDMO.HHZ. 2021-10-31T07:50:10.35 0.1 undecidable manual P 18 26.3514 50 -0.08 98
IV.MMO1.EHZ. 2021-10-31T07:50:10.83 0.3 positive manual P 70 29.3484 50 -0.05 74
IV.NRCA.HHZ. 2021-10-31T07:50:09.69 0.3 undecidable manual S 76 10.6782 135 -0.39 71
IV.LNSS.HHZ. 2021-10-31T07:50:09.99 0.1 undecidable manual P 169 23.3544 50 0.03 100
IV.MC2.EHZ. 2021-10-31T07:50:09.47 0.3 undecidable manual P 55 19.869 118 0.09 74
IV.GAVE.EHZ. 2021-10-31T07:50:08.63 0.3 undecidable manual P 210 15.0738 125 0.06 75
IV.NRCA.HHZ. 2021-10-31T07:50:07.76 0.1 undecidable manual P 76 10.6782 135 -0.12 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.NRCA.HHE. ML:1.2 0.00017549999999999998 0.18 AML other m 2021-10-31T07:50:10.09
IV.GAVE.EHE. ML:1.1 0.0001205 0.12 AML other m 2021-10-31T07:50:11.46
IV.NRCA.HHN. ML:1.0 0.0001295 0.94 AML other m 2021-10-31T07:50:11.78
IV.GAVE.EHN. ML:1.1 0.000113 0.16 AML other m 2021-10-31T07:50:11.91
IV.CESI.HHN. ML:1.2 0.00009484999999999999 0.24 AML other m 2021-10-31T07:50:13.55
IV.FDMO.HHN. ML:0.8 0.00003455 0.2 AML other m 2021-10-31T07:50:14.85
IV.LNSS.HHN. ML:0.9 0.000045600000000000004 1.38 AML other m 2021-10-31T07:50:14.80
IV.LNSS.HHE. ML:0.9 0.000050549999999999995 1.58 AML other m 2021-10-31T07:50:15.79
IV.FDMO.HHE. ML:0.7 0.0000305 1.24 AML other m 2021-10-31T07:50:15.04
IV.CESI.HHE. ML:0.8 0.000045600000000000004 1.32 AML other m 2021-10-31T07:50:17.14
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