INGVCENTRO​NAZIONALE​TERREMOTI
Sala Sismica

Earthquake with magnitude of ML 1.8 on date 17-02-2019 and time 16:53:34 (UTC) in region 4 km W Semproniano (GR)

A magnitude ML 1.8 earthquake occured in region: 4 km W Semproniano (GR), on

  • 17-02-2019 16:53:34 (UTC)
  • 17-02-2019 17:53:34 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.74, 11.49 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Semproniano GR 4 1059 1059
Roccalbegna GR 6 1044 2103
Santa Fiora GR 13 2622 4725
Scansano GR 14 4427 9152
Arcidosso GR 16 4285 13437
Manciano GR 17 7354 20791
Castell'Azzara GR 17 1476 22267
Castel del Piano GR 18 4690 26957
Pitigliano GR 18 3818 30775
Sorano GR 19 3428 34203
Cinigiano GR 19 2618 36821

Municipalities with at least 50000 inhabitants

An earthquake occurred to
31 Km E of Grosseto (82087 inhabitants)
61 Km NW of Viterbo (67173 inhabitants)
66 Km S of Siena (53903 inhabitants)
76 Km NW of Civitavecchia (52991 inhabitants)
84 Km SW of Perugia (166134 inhabitants)
87 Km SW of Arezzo (99543 inhabitants)
96 Km W of Terni (111501 inhabitants)
Recent and historical Seismicity
Seismic hazard
Shakemap
Felt maps
The earthquake effects in MCS scale as obtained from the compiled questionnaire

The earthquake effects in MCS scale as obtained from the compiled 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
Rev 100 ML 1.8 2019-02-17
16:53:34
42.74 11.49 8 2019-02-17
17:27:50
Sala Sismica INGV-Roma 65631781
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2019-02-17 16:53:34 ± 0.12
Latitude 42.74 ± 0.01
Longitude 11.49 ± 0.01
Depth (km) 8 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 65631781

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 863
Semi-minor axis of confidence ellipse (meter) 830
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 82
Circular confidence region, given by single value of horizontal uncertainty (meter) 860
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 159
Number of associated phases, regardless of their use for origin computation 19
Number of defining phases 19
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) 0.09083
Epicentral distance of station farthest from the epicenter (degree) 0.68618
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 12
Magnitude information

ML:1.8

Field Value
Value 1.8
Uncertainty 0.3
Num. used stations 8
Type of magnitude ML
Reference to an origin 65631781
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2019-02-17 17:27:50
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.CAFI.HHE. 2019-02-17T16:53:48.29 0.3 undecidable manual P 30 0.6862 50 -0.06 67
IV.TRIF.CHE. 2019-02-17T16:53:46.66 0.1 undecidable manual P 311 0.5756 50 0.2 89
IV.FROS.CHE. 2019-02-17T16:53:45.83 0.1 undecidable manual P 333 0.5342 50 0.07 92
IV.CASP.HHE. 2019-02-17T16:53:44.12 0.1 undecidable manual P 277 0.4649 50 -0.44 86
TV.SF11.HHZ. 2019-02-17T16:53:42.21 0.3 undecidable manual S 45 0.1898 111 -0.47 68
TV.SF03.EHZ. 2019-02-17T16:53:41.47 0.3 undecidable manual S 64 0.1556 115 0 76
TV.SF04.EHZ. 2019-02-17T16:53:41.49 0.3 undecidable manual S 51 0.1574 115 -0.05 75
TV.SF13.HHZ. 2019-02-17T16:53:40.40 0.3 undecidable manual S 48 0.1241 121 0.02 76
IV.LATE.HHZ. 2019-02-17T16:53:40.75 0.6 undecidable manual P 118 0.2581 106 -0.05 49
IV.MCIV.CHZ. 2019-02-17T16:53:40.94 0.3 undecidable manual S 72 0.1403 118 0 76
TV.SF01.EHZ. 2019-02-17T16:53:39.37 0.3 undecidable manual S 34 0.0917 129 0.01 76
TV.SF11.HHZ. 2019-02-17T16:53:39.20 0.6 undecidable manual P 45 0.1898 111 -0.16 49
TV.SF14.HHZ. 2019-02-17T16:53:39.00 0.3 undecidable manual S 77 0.0908 129 -0.33 72
TV.SF03.EHZ. 2019-02-17T16:53:38.90 0.1 undecidable manual P 64 0.1556 115 0.24 96
TV.SF04.EHZ. 2019-02-17T16:53:38.93 0.3 negative manual P 51 0.1574 115 0.23 72
TV.SF13.HHZ. 2019-02-17T16:53:38.25 0.3 undecidable manual P 48 0.1241 121 0.22 73
IV.MCIV.CHZ. 2019-02-17T16:53:38.68 0.1 undecidable manual P 72 0.1403 118 0.32 95
TV.SF14.HHZ. 2019-02-17T16:53:37.31 0.1 undecidable manual P 77 0.0908 129 -0.12 100
TV.SF01.EHZ. 2019-02-17T16:53:37.55 0.1 undecidable manual P 34 0.0917 129 0.1 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF01.EHE. ML:1.9 0.0010645 1.74 AML other m 2019-02-17T16:53:39.92
TV.SF01.EHN. ML:1.9 0.0010025 1.72 AML other m 2019-02-17T16:53:39.07
IV.MCIV.CHE. ML:1.8 0.000696 0.24 AML other m 2019-02-17T16:53:41.94
IV.MCIV.CHN. ML:1.7 0.00051 1.14 AML other m 2019-02-17T16:53:42.83
TV.SF04.EHN. ML:2.2 0.00132 0.34 AML other m 2019-02-17T16:53:42.62
TV.SF04.EHE. ML:2.1 0.001175 0.26 AML other m 2019-02-17T16:53:44.30
IV.LATE.HHE. ML:1.3 0.0001102 0.88 AML other m 2019-02-17T16:53:50.32
IV.LATE.HHN. ML:1.5 0.0001755 1.46 AML other m 2019-02-17T16:53:50.89
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download