Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.0 on date 17-08-2021 and time 20:16:02 (Italy) in region 3 km NE Massa Martana (PG)

A magnitude ML 1.0 earthquake occured in region: 3 km NE Massa Martana (PG), on

  • 17-08-2021 18:16:02 (UTC)
  • 17-08-2021 20:16:02 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7910, 12.5510 at 8 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
Massa Martana PG 3 3770 3770
Giano dell'Umbria PG 5 3846 7616
Castel Ritaldi PG 11 3278 10894
Acquasparta TR 11 4778 15672
Todi PG 12 16851 32523
Gualdo Cattaneo PG 13 6155 38678
Montefalco PG 14 5679 44357
Collazzone PG 15 3473 47830
Montecastrilli TR 16 5022 52852
Spoleto PG 17 38218 91070
Fratta Todina PG 17 1839 92909
Bevagna PG 17 5081 97990
Monte Castello di Vibio PG 17 1567 99557
Avigliano Umbro TR 18 2558 102115
Campello sul Clitunno PG 19 2442 104557
Trevi PG 19 8469 113026
San Gemini TR 20 5018 118044

Municipalities with at least 50000 inhabitants

An earthquake occurred to
22 Km SW of Foligno (57155 inhabitants)
27 Km NW of Terni (111501 inhabitants)
38 Km SE of Perugia (166134 inhabitants)
55 Km NE of Viterbo (67173 inhabitants)
85 Km NW of L'Aquila (69753 inhabitants)
89 Km N of Guidonia Montecelio (88673 inhabitants)
93 Km SE of Arezzo (99543 inhabitants)
94 Km N of Tivoli (56533 inhabitants)
95 Km W of Teramo (54892 inhabitants)
99 Km NE of Civitavecchia (52991 inhabitants)
100 Km N 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 1.0 2021-08-17
18:16:02		 42.7913 12.5508 8 2021-08-17
18:23:35		 Sala Sismica INGV-Roma 94306731
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-17 18:16:02 ± 0.07
Latitude 42.7913 ± 0.0036
Longitude 12.5508 ± 0.0061
Depth (km) 8 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 94306731

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 525
Semi-minor axis of confidence ellipse (meter) 339
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 268
Circular confidence region, given by single value of horizontal uncertainty (meter) 520.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 119
Number of associated phases, regardless of their use for origin computation 37
Number of defining phases 20
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.24
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.67179
Number of stations at which the event was observed 27
Number of stations from which data was used for origin computation 10
Magnitude information

ML:1.0

Field Value
Value 1.0
Uncertainty 0.2
Num. used stations 9
Type of magnitude ML
Reference to an origin 94306731
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-17 18:23:35
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
GU.RORO.HHZ. 2021-08-17T18:17:52.75 3.0 undecidable manual Sg 13.63 0
IV.ZONE.HHZ. 2021-08-17T18:17:45.54 3.0 undecidable manual Sg 9.2 0
IV.SOI.EHZ. 2021-08-17T18:17:41.22 3.0 undecidable manual Pg 17.870001 0
GU.CANO.HHZ. 2021-08-17T18:17:38.16 3.0 undecidable manual Sn 1.04 0
IV.CAGR.HHZ. 2021-08-17T18:17:37.26 3.0 undecidable manual Pg 14.37 0
IV.TREG.EHZ. 2021-08-17T18:17:32.98 3.0 undecidable manual Sg 10.01 0
IV.ESCV.HHZ. 2021-08-17T18:17:19.30 3.0 undecidable manual Pn -2.92 0
GU.GBOS.HHZ. 2021-08-17T18:17:09.35 3.0 undecidable manual Pg 9.65 0
IV.VAGA.HHZ. 2021-08-17T18:16:59.61 3.0 undecidable manual Sg 0.81 0
IV.ZEN8.EHZ. 2021-08-17T18:16:57.63 3.0 undecidable manual Pg 6.6 0
IV.SCHR.EHZ. 2021-08-17T18:16:54.00 3.0 undecidable manual Pn -5.6 0
IV.MILN.HNZ. 2021-08-17T18:16:53.89 3.0 negative manual Pn -3.73 0
IX.NSC3.EHZ.02 2021-08-17T18:16:51.84 3.0 undecidable manual Pg 5.56 0
IX.SCL3.EHZ.02 2021-08-17T18:16:48.69 3.0 negative manual Pn -1.9 0
IV.SBPO.HNZ. 2021-08-17T18:16:45.93 3.0 positive manual Pg 2.87 0
GU.GSCL.HHZ. 2021-08-17T18:16:38.38 3.0 undecidable manual Pg 1.1 0
IV.CPGN.HNZ. 2021-08-17T18:16:33.08 3.0 undecidable manual Sg -3.67 0
IV.EL6.EHZ. 2021-08-17T18:16:26.02 0.6 undecidable manual S 37 74.5698 50 0.88 34
IV.CSP1.EHZ. 2021-08-17T18:16:21.98 0.1 undecidable manual S 58 62.6928 50 -0.01 91
IV.MC2.EHZ. 2021-08-17T18:16:19.80 0.3 undecidable manual S 75 53.6019 50 0.25 66
IV.MGAB.HHZ. 2021-08-17T18:16:15.33 0.3 undecidable manual S 291 38.1285 50 -0.1 70
IV.EL6.EHZ. 2021-08-17T18:16:15.20 0.1 undecidable manual P 37 74.5698 50 -0.16 86
IV.CESI.HNE. 2021-08-17T18:16:14.82 0.1 undecidable manual S 50 37.2294 50 -0.37 88
IV.CSP1.EHZ. 2021-08-17T18:16:13.35 0.1 undecidable manual P 58 62.6928 50 -0.19 88
IV.MC2.EHZ. 2021-08-17T18:16:12.67 0.3 undecidable manual P 75 53.6019 50 0.54 62
IV.ARRO.EHZ. 2021-08-17T18:16:12.64 0.1 undecidable manual S 143 29.3484 104 0.12 95
IV.ASSB.HHZ. 2021-08-17T18:16:12.49 0.1 undecidable manual S 17 29.2485 104 0.01 97
IV.CESI.HNE. 2021-08-17T18:16:09.36 0.1 undecidable manual P 50 37.2294 50 -0.26 91
IV.CESX.HHZ. 2021-08-17T18:16:09.47 0.1 undecidable manual S 172 20.4684 110 -0.12 96
IV.MGAB.HHZ. 2021-08-17T18:16:09.95 0.1 undecidable manual P 291 38.1285 50 0.2 92
IV.ARRO.EHZ. 2021-08-17T18:16:07.95 0.1 undecidable manual P 143 29.3484 104 -0.12 95
IV.ASSB.HHZ. 2021-08-17T18:16:07.97 0.1 undecidable manual P 17 29.2485 104 -0.09 95
IV.CESX.HHZ. 2021-08-17T18:16:06.34 0.1 undecidable manual P 172 20.4684 110 -0.04 98
IV.MOMA.HHZ. 2021-08-17T18:16:04.64 0.1 undecidable manual S 48 2.0979 164 -0.09 100
IT.GNU.HGN. 2021-08-17T18:16:04.65 0.1 undecidable manual S 48 2.0979 164 -0.08 100
IT.GNU.HGN. 2021-08-17T18:16:03.81 0.1 undecidable manual P 48 2.0979 164 0.23 97
IV.MOMA.HHZ. 2021-08-17T18:16:03.76 0.1 undecidable manual P 48 2.0979 164 0.18 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.CESX.HHN. ML:1.1 0.00010564999999999999 0.62 AML other m 2021-08-17T18:16:10.18
IV.CESX.HHE. ML:1.2 0.0001177 0.34 AML other m 2021-08-17T18:16:11.63
IV.MGAB.HHN. ML:1.1 0.000045350000000000005 0.56 AML other m 2021-08-17T18:16:16.39
IV.MGAB.HHE. ML:1.0 0.000033150855 1.6384 AML other m 2021-08-17T18:16:16.99
IV.ARRO.EHE. ML:0.8 0.00003618685 0.1664 AML other m 2021-08-17T18:16:14.32
IV.ARRO.EHN. ML:0.9 0.00003808127 0.2176 AML other m 2021-08-17T18:16:14.82
IV.ASSB.HHE. ML:0.9 0.000040446015 0.2176 AML other m 2021-08-17T18:16:12.83
IV.ASSB.HHN. ML:1.0 0.000046155925 0.192 AML other m 2021-08-17T18:16:12.72
IV.CSP1.EHN. ML:1.6 0.000073473975 0.2304 AML other m 2021-08-17T18:16:22.44
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