Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.6 on date 29-09-2023 and time 11:22:21 (UTC) in region 4 km W Bolsena (VT)

A magnitude ML 1.6 earthquake occured in region: 4 km W Bolsena (VT), on

  • 29-09-2023 11:22:21 (UTC)
  • 29-09-2023 13:22:21 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.6540, 11.9370 at 2 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
Bolsena VT 4 3991 3991
San Lorenzo Nuovo VT 4 2091 6082
Grotte di Castro VT 6 2683 8765
Gradoli VT 7 1353 10118
Castel Giorgio TR 7 2131 12249
Latera VT 9 836 13085
Onano VT 11 995 14080
Acquapendente VT 12 5506 19586
Capodimonte VT 12 1731 21317
Castel Viscardo TR 13 2938 24255
Marta VT 13 3499 27754
Valentano VT 13 2868 30622
Bagnoregio VT 14 3650 34272
Lubriano VT 14 909 35181
Porano TR 14 1966 37147
Proceno VT 14 557 37704
Montefiascone VT 15 13432 51136
Orvieto TR 16 20630 71766
Piansano VT 18 2079 73845
Allerona TR 18 1794 75639
Sorano GR 19 3428 79067
Celleno VT 19 1355 80422
Ischia di Castro VT 19 2326 82748

Municipalities with at least 50000 inhabitants

An earthquake occurred to
30 Km NW of Viterbo (67173 inhabitants)
59 Km W of Terni (111501 inhabitants)
62 Km SW of Perugia (166134 inhabitants)
64 Km N of Civitavecchia (52991 inhabitants)
68 Km E of Grosseto (82087 inhabitants)
71 Km W of Foligno (57155 inhabitants)
89 Km SE of Siena (53903 inhabitants)
91 Km S of Arezzo (99543 inhabitants)
96 Km NW of Roma (2864731 inhabitants)
97 Km NW of Guidonia Montecelio (88673 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 1.6 2023-09-29
11:22:21		 42.6542 11.9372 2 2023-09-29
11:38:58		 Sala Sismica INGV-Roma 121581531
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2023-09-29 11:22:21 ± 0.1
Latitude 42.6542 ± 0.0045
Longitude 11.9372 ± 0.0061
Depth (km) 2 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 121581531

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 504
Semi-minor axis of confidence ellipse (meter) 273
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 5
Circular confidence region, given by single value of horizontal uncertainty (meter) 500.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 132
Number of associated phases, regardless of their use for origin computation 30
Number of defining phases 16
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) 0.74464
Number of stations at which the event was observed 22
Number of stations from which data was used for origin computation 8
Magnitude information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 121581531
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2023-09-29 11:38:58
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.EPOZ.HHZ. 2023-09-29T11:24:02.09 3.0 undecidable manual Pg 22.75 0
IV.CMPR.HHZ. 2023-09-29T11:24:00.02 3.0 undecidable manual Sn 1.85 0
IV.ECTS.HHZ. 2023-09-29T11:23:44.01 3.0 undecidable manual Pn 7.53 0
GU.SATI.HHZ. 2023-09-29T11:23:43.69 3.0 undecidable manual Sn -9.99 0
IV.SALB.HHZ. 2023-09-29T11:23:42.95 3.0 undecidable manual Pg 18.35 0
IV.GRI.EHZ. 2023-09-29T11:23:41.49 3.0 undecidable manual Pn 6.63 0
IV.SELL.HHZ. 2023-09-29T11:23:40.77 3.0 positive manual Pn 5.88 0
IV.AIO.HHZ. 2023-09-29T11:23:36.14 3.0 negative manual Pn 0.06 0
GU.PCP.HHZ. 2023-09-29T11:23:23.33 3.0 undecidable manual Sg 0.73 0
IV.PTCC.HHZ. 2023-09-29T11:23:16.96 3.0 undecidable manual Pg 5.01 0
SI.KOSI.HHZ. 2023-09-29T11:23:14.61 3.0 undecidable manual Pg 6.59 0
IV.MOCO.HHZ. 2023-09-29T11:23:12.54 3.0 undecidable manual Pg 9.4 0
MN.TUE.HHZ. 2023-09-29T11:23:10.88 3.0 positive manual Pg 0.1 0
IV.MURB.HHZ. 2023-09-29T11:22:48.24 0.6 undecidable manual S 35 82.6506 50 -0.16 45
GU.RNCA.HHZ. 2023-09-29T11:22:48.37 3.0 undecidable manual Pg -0.39 0
IV.ATMI.HHZ. 2023-09-29T11:22:47.62 0.6 undecidable manual S 19 80.0643 50 -0.08 46
IV.MOMA.HHZ. 2023-09-29T11:22:41.30 0.6 undecidable manual S 72 54.2013 92 0.62 43
IV.ARCI.HNZ. 2023-09-29T11:22:37.32 0.6 undecidable manual S 300 43.5231 93 0.33 47
IV.ATMI.HHZ. 2023-09-29T11:22:37.18 0.1 undecidable manual P 19 80.0643 50 0.4 87
IV.BARO.EHZ. 2023-09-29T11:22:37.72 0.6 undecidable manual S 168 46.0206 93 -0.12 49
IV.MURB.HHZ. 2023-09-29T11:22:36.99 0.1 undecidable manual P 35 82.6506 50 -0.19 90
IV.MOMA.HHZ. 2023-09-29T11:22:32.50 0.6 negative manual P 72 54.2013 92 -0.22 47
IV.MGAB.HHZ. 2023-09-29T11:22:32.98 0.6 undecidable manual S 26 32.0457 94 -0.01 51
IV.BARO.EHZ. 2023-09-29T11:22:31.04 1.0 positive manual P 168 46.0206 93 -0.05 25
IV.MCIV.CHE. 2023-09-29T11:22:30.47 0.3 undecidable manual S 303 25.3524 95 -0.21 75
IV.ARCI.HNZ. 2023-09-29T11:22:30.54 0.1 undecidable manual P 300 43.5231 93 -0.05 100
IV.SACS.HHZ. 2023-09-29T11:22:29.37 0.6 undecidable manual S 354 21.7671 95 -0.07 52
IV.MGAB.HHZ. 2023-09-29T11:22:27.93 0.3 positive manual P 26 32.0457 94 -0.36 72
IV.MCIV.CHE. 2023-09-29T11:22:27.17 0.1 undecidable manual P 303 25.3524 95 0.22 100
IV.SACS.HHZ. 2023-09-29T11:22:26.21 0.3 undecidable manual P 354 21.7671 95 -0.02 78
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.SACS.HHN. ML:1.4 0.00020500000000000002 1.24 AML other m 2023-09-29T11:22:30.97
IV.SACS.HHE. ML:1.9 0.0005535 1.24 AML other m 2023-09-29T11:22:30.36
IV.MGAB.HHN. ML:1.6 0.000211 0.76 AML other m 2023-09-29T11:22:34.46
IV.MGAB.HHE. ML:1.6 0.0002035 0.26 AML other m 2023-09-29T11:22:36.23
IV.SACS.HNE. ML:1.8 0.0004979824 0.2048 AML other m 2023-09-29T11:22:30.36
IV.SACS.HNN. ML:1.4 0.00019603065 0.3008 AML other m 2023-09-29T11:22:29.74
IV.MGAB.HNE. ML:1.6 0.0002061123 0.2688 AML other m 2023-09-29T11:22:36.23
IV.MGAB.HNN. ML:1.6 0.00020440635 0.3072 AML other m 2023-09-29T11:22:34.31
IV.MOMA.HHE. ML:1.2 0.0000380524 0.416 AML other m 2023-09-29T11:22:43.47
IV.MOMA.HHN. ML:1.4 0.00006336886499999999 0.4032 AML other m 2023-09-29T11:22:51.53
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