Earthquake with magnitude of ML 0.9 on date 11-09-2021 and time 04:14:52 (UTC) in region 2 km W Acquasparta (TR)

A magnitude ML 0.9 earthquake occured in region: 2 km W Acquasparta (TR), on

  • 11-09-2021 04:14:52 (UTC)
  • 11-09-2021 06:14:52 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.69, 12.528 at 9 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Acquasparta TR 2 4778 4778
Montecastrilli TR 5 5022 9800
San Gemini TR 9 5018 14818
Avigliano Umbro TR 9 2558 17376
Massa Martana PG 10 3770 21146
Todi PG 14 16851 37997
Giano dell'Umbria PG 17 3846 41843
Terni TR 17 111501 153344
Amelia TR 17 11897 165241
Spoleto PG 18 38218 203459
Narni TR 19 19785 223244
Castel Ritaldi PG 19 3278 226522
Montecchio TR 20 1676 228198

Municipalities with at least 50000 inhabitants

An earthquake occurred to
17 Km NW of Terni (111501 inhabitants)
33 Km SW of Foligno (57155 inhabitants)
46 Km NE of Viterbo (67173 inhabitants)
48 Km S of Perugia (166134 inhabitants)
78 Km N of Guidonia Montecelio (88673 inhabitants)
81 Km W of L'Aquila (69753 inhabitants)
84 Km N of Tivoli (56533 inhabitants)
89 Km N of Roma (2864731 inhabitants)
90 Km NE of Civitavecchia (52991 inhabitants)
96 Km W of Teramo (54892 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
Felt maps
Preliminary map of the earthquake effects from the web questionnaire

Preliminary map of the earthquake effects from the web questionnaire

This map shows the distribution of the effects of the earthquake on the territory in terms of the MCS (Mercalli-Cancani-Sieberg) intensity scale. The intensities are determined using the data provided in the questionnaire (http://www.haisentitoilterremoto.it/) that are analysed using robust statistical techniques since they are not verified individually. Specifically, the assignment of MCS intensities greater or equal the VI degree of the MCS scale require opportune in situ verification by professional experts. The purple start shows the epicenter. This map is prepared every so often that the population fill in new questionnaires. The number of questionnaires used to determine the map and the date and time of the last adjournment are shown in the upper right part of the panel.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Reviewed
Rev100
ML 0.9 2021-09-11
04:14:52
42.6897 12.5283 9 2021-09-11
04:20:33
Sala Sismica INGV-Roma 95289641
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-09-11 04:14:52 ± 0.14
Latitude 42.6897 ± 0.0045
Longitude 12.5283 ± 0.0135
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 95289641

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1084
Semi-minor axis of confidence ellipse (meter) 227
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 77
Circular confidence region, given by single value of horizontal uncertainty (meter) 1080
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 154
Number of associated phases, regardless of their use for origin computation 13
Number of defining phases 13
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.21
Epicentral distance of station closest to the epicenter (degree) 0.09173
Epicentral distance of station farthest from the epicenter (degree) 0.63762
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitude information

ML:0.9

Field Value
Value 0.9
Uncertainty 0.2
Num. used stations 10
Type of magnitude ML
Reference to an origin 95289641
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-09-11 04:20:33
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.ASSB.HHZ. 2021-09-11T04:15:06.11 0.3 undecidable manual S 15 0.3651 50 -0.07 72
IV.CSP1.EHZ. 2021-09-11T04:15:05.02 1.0 negative manual P 51 0.6376 50 -0.01 23
IV.MGAB.HHZ. 2021-09-11T04:15:01.30 0.6 negative manual P 306 0.3777 50 0.71 40
IV.ARRO.EHZ. 2021-09-11T04:15:01.15 0.3 undecidable manual S 122 0.2068 111 0.17 73
IV.ASSB.HHZ. 2021-09-11T04:15:00.08 0.3 negative manual P 15 0.3651 50 -0.29 69
IV.GAVE.EHZ. 2021-09-11T04:14:58.84 0.3 undecidable manual P 89 0.2689 107 0.16 72
IV.MOMA.HHZ. 2021-09-11T04:14:58.06 0.3 undecidable manual S 15 0.1178 124 0.1 75
IT.GNU.HGE. 2021-09-11T04:14:58.11 0.1 undecidable manual S 15 0.1178 124 0.16 99
IV.ARRO.EHZ. 2021-09-11T04:14:57.56 1.0 positive manual P 122 0.2068 111 0.19 24
IV.CESX.HHZ. 2021-09-11T04:14:57.06 0.3 undecidable manual S 152 0.0917 131 -0.09 76
IV.CESX.HHZ. 2021-09-11T04:14:55.02 0.1 undecidable manual P 152 0.0917 131 -0.14 100
IV.MOMA.HHZ. 2021-09-11T04:14:55.43 0.1 positive manual P 15 0.1178 124 -0.19 98
IT.GNU.HGE. 2021-09-11T04:14:55.47 0.1 undecidable manual P 15 0.1178 124 -0.15 99
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.CESX.HHN. ML:1.2 0.000207 0.2 AML other m 2021-09-11T04:14:57.82
IV.MOMA.HHE. ML:1.2 0.000166 0.16 AML other m 2021-09-11T04:14:58.65
IV.CESX.HHE. ML:1.2 0.00021 0.42 AML other m 2021-09-11T04:14:58.71
IV.MOMA.HHN. ML:1.1 0.0001415 0.76 AML other m 2021-09-11T04:15:00.43
IV.ARRO.EHN. ML:0.9 5.315E-5 0.18 AML other m 2021-09-11T04:15:02.09
IV.ARRO.EHE. ML:0.7 3.05E-5 0.86 AML other m 2021-09-11T04:15:02.89
IV.ASSB.HHE. ML:0.8 1.995E-5 0.36 AML other m 2021-09-11T04:15:07.63
IV.ASSB.HHN. ML:0.6 1.695E-5 1 AML other m 2021-09-11T04:15:08.18
IV.MGAB.HHE. ML:0.8 2.245E-5 1.34 AML other m 2021-09-11T04:15:09.06
IV.MGAB.HHN. ML:0.9 2.715E-5 0.12 AML other m 2021-09-11T04:15:09.35
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