Earthquake with magnitude of ML 0.9 on date 28-09-2021 and time 03:50:35 (Italy) in region 7 km SW Spoleto (PG)

A magnitude ML 0.9 earthquake occured in region: 7 km SW Spoleto (PG), on

  • 28-09-2021 01:50:35 (UTC)
  • 28-09-2021 03:50:35 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.697, 12.677 at 14 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
Spoleto PG 7 38218 38218
Acquasparta TR 11 4778 42996
Ferentillo TR 13 1913 44909
Scheggino PG 13 461 45370
Montefranco TR 13 1276 46646
Sant'Anatolia di Narco PG 14 564 47210
San Gemini TR 14 5018 52228
Castel Ritaldi PG 14 3278 55506
Arrone TR 15 2763 58269
Terni TR 15 111501 169770
Massa Martana PG 15 3770 173540
Campello sul Clitunno PG 16 2442 175982
Montecastrilli TR 16 5022 181004
Vallo di Nera PG 17 364 181368
Giano dell'Umbria PG 17 3846 185214
Polino TR 19 233 185447

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km N of Terni (111501 inhabitants)
29 Km S of Foligno (57155 inhabitants)
51 Km SE of Perugia (166134 inhabitants)
56 Km NE of Viterbo (67173 inhabitants)
71 Km NW of L'Aquila (69753 inhabitants)
78 Km N of Guidonia Montecelio (88673 inhabitants)
82 Km N of Tivoli (56533 inhabitants)
84 Km W of Teramo (54892 inhabitants)
91 Km N of Roma (2864731 inhabitants)
99 Km NE of Civitavecchia (52991 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 2021-09-28
01:50:35
42.6972 12.6772 14 2021-09-28
01:57:05
Sala Sismica INGV-Roma 95970261
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-09-28 01:50:35 ± 0.12
Latitude 42.6972 ± 0.0036
Longitude 12.6772 ± 0.0037
Depth (km) 14 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 95970261

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 327
Semi-minor axis of confidence ellipse (meter) 219
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 51
Circular confidence region, given by single value of horizontal uncertainty (meter) 330
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 107
Number of associated phases, regardless of their use for origin computation 11
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.12
Epicentral distance of station closest to the epicenter (degree) 0
Epicentral distance of station farthest from the epicenter (degree) 0.34984
Number of stations at which the event was observed 6
Number of stations from which data was used for origin computation 5
Magnitude information

ML:0.9

Field Value
Value 0.9
Uncertainty 0.2
Num. used stations 6
Type of magnitude ML
Reference to an origin 95970261
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-09-28 01:57:05
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.VCEL.EHZ. 2021-09-28T01:50:54.63 3.0 undecidable manual P 0.17 0
IV.CESI.HHZ. 2021-09-28T01:50:48.74 0.3 undecidable manual S 28 0.3498 97 0.07 72
IV.GAVE.EHZ. 2021-09-28T01:50:43.11 0.3 undecidable manual S 92 0.1592 114 -0.07 73
IV.CESI.HHZ. 2021-09-28T01:50:43.10 0.1 undecidable manual P 28 0.3498 97 -0.13 92
IV.MOMA.HHZ. 2021-09-28T01:50:42.44 0.3 undecidable manual S 324 0.1322 121 -0.03 74
IV.ARRO.EHZ. 2021-09-28T01:50:42.55 0.3 undecidable manual S 151 0.1349 120 0.02 75
IV.CESX.HHZ. 2021-09-28T01:50:41.82 0.3 undecidable manual S 217 0.1106 128 -0.12 73
IV.GAVE.EHZ. 2021-09-28T01:50:40.01 0.1 undecidable manual P 92 0.1592 114 -0.05 97
IV.ARRO.EHZ. 2021-09-28T01:50:39.87 0.1 undecidable manual P 151 0.1349 120 0.18 97
IV.CESX.HHZ. 2021-09-28T01:50:39.38 0.1 undecidable manual P 217 0.1106 128 0.03 100
IV.MOMA.HHZ. 2021-09-28T01:50:39.76 0.1 undecidable manual P 324 0.1322 121 0.1 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.CESX.HHE. ML:0.8 6.095E-5 0.16 AML other m 2021-09-28T01:50:42.04
IV.MOMA.HHE. ML:1 8.13E-5 1.48 AML other m 2021-09-28T01:50:42.02
IV.CESX.HHN. ML:0.9 6.88E-5 1.14 AML other m 2021-09-28T01:50:42.26
IV.MOMA.HHN. ML:1.1 0.000112 0.32 AML other m 2021-09-28T01:50:42.99
IV.GAVE.EHN. ML:0.7 3.4E-5 1.5 AML other m 2021-09-28T01:50:43.84
IV.GAVE.EHE. ML:0.6 3.21E-5 0.22 AML other m 2021-09-28T01:50:43.90
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