Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 1.2 on date 20-01-2021 and time 18:39:54 (UTC) in region 5 km W Arquata del Tronto (AP)

A magnitude ML 1.2 earthquake occured in region: 5 km W Arquata del Tronto (AP), on

  • 20-01-2021 18:39:54 (UTC)
  • 20-01-2021 19:39:54 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 42.77, 13.24 at 11 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
Arquata del Tronto AP 5 1178 1178
Accumoli RI 8 667 1845
Montegallo AP 12 523 2368
Norcia PG 12 4957 7325
Acquasanta Terme AP 14 2916 10241
Amatrice RI 16 2657 12898
Castelsantangelo sul Nera MC 16 281 13179
Montemonaco AP 17 604 13783
Cittareale RI 18 482 14265
Cascia PG 19 3217 17482

Municipalities with at least 50000 inhabitants

An earthquake occurred to
40 Km W of Teramo (54892 inhabitants)
48 Km N of L'Aquila (69753 inhabitants)
48 Km E of Foligno (57155 inhabitants)
53 Km E of Terni (111501 inhabitants)
79 Km E of Perugia (166134 inhabitants)
80 Km W of Montesilvano (53738 inhabitants)
87 Km W of Pescara (121014 inhabitants)
89 Km NW of Chieti (51815 inhabitants)
95 Km NE of Guidonia Montecelio (88673 inhabitants)
96 Km NE of Tivoli (56533 inhabitants)
97 Km S of Ancona (100861 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
Reviewed
Rev100 		ML 1.2 2021-01-20
18:39:54		 42.77 13.24 11 2021-01-20
18:43:42		 Sala Sismica INGV-Roma 86406481
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-01-20 18:39:54 ± 0.04
Latitude 42.77 ± 0.00
Longitude 13.24 ± 0.00
Depth (km) 11 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 86406481

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 309
Semi-minor axis of confidence ellipse (meter) 157
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 55
Circular confidence region, given by single value of horizontal uncertainty (meter) 310
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 155
Number of associated phases, regardless of their use for origin computation 22
Number of defining phases 14
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.09
Epicentral distance of station closest to the epicenter (degree) 0
Epicentral distance of station farthest from the epicenter (degree) 0.34174
Number of stations at which the event was observed 15
Number of stations from which data was used for origin computation 7
Magnitude information

ML:1.2

Field Value
Value 1.2
Uncertainty 0.2
Num. used stations 18
Type of magnitude ML
Reference to an origin 86406481
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-01-20 18:43:42
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.CSP1.EHZ. 2021-01-20T18:40:06.38 0.6 undecidable manual S 356 0.3265 50 0.06 48
IV.CESI.HHZ. 2021-01-20T18:40:06.68 0.6 undecidable manual S 314 0.3417 50 -0.09 48
IV.VCEL.EHZ. 2021-01-20T18:40:05.96 3.0 undecidable manual P 0.01 0
IV.ARRO.EHZ. 2021-01-20T18:40:02.44 3.0 undecidable manual P 0.02 0
IV.CSP1.EHZ. 2021-01-20T18:40:01.11 0.6 positive manual P 356 0.3265 50 -0.05 48
IV.CESI.HHZ. 2021-01-20T18:40:01.34 0.3 positive manual P 314 0.3417 50 -0.07 72
IV.MF5.EHZ. 2021-01-20T18:40:00.66 3.0 negative manual P 0.43 0
IV.FDMO.HHZ. 2021-01-20T18:40:00.31 3.0 undecidable manual Pn -0.16 0
IV.MMO1.EHZ. 2021-01-20T18:40:00.85 0.6 undecidable manual S 26 0.1484 123 -0.04 50
IV.TERO.HHZ. 2021-01-20T18:40:00.67 3.0 undecidable manual P -0.22 0
IV.SMA1.EHZ. 2021-01-20T18:40:00.94 0.6 undecidable manual S 152 0.1529 122 -0.11 49
IV.MC2.EHZ. 2021-01-20T18:40:00.87 0.3 undecidable manual S 346 0.1493 123 -0.07 74
IV.NRCA.HNZ. 2021-01-20T18:39:59.69 0.6 undecidable manual S 307 0.1133 130 -0.11 49
IV.RM33.EHZ. 2021-01-20T18:39:59.97 3.0 negative manual P -0.01 0
IV.MTRA.HNZ. 2021-01-20T18:39:59.80 0.3 undecidable manual S 95 0.1169 129 -0.11 74
IV.LNSS.HHZ. 2021-01-20T18:39:59.23 3.0 negative manual P 0.01 0
IV.GAVE.EHZ. 2021-01-20T18:39:59.98 3.0 positive manual Pg -0.01 0
IV.MMO1.EHZ. 2021-01-20T18:39:58.05 0.1 undecidable manual P 26 0.1484 123 0.03 100
IV.SMA1.EHZ. 2021-01-20T18:39:58.20 0.6 undecidable manual P 152 0.1529 122 0.09 49
IV.MC2.EHZ. 2021-01-20T18:39:58.18 0.1 undecidable manual P 346 0.1493 123 0.13 98
IV.NRCA.HNZ. 2021-01-20T18:39:57.47 0.1 negative manual P 307 0.1133 130 0.08 100
IV.MTRA.HNZ. 2021-01-20T18:39:57.64 0.6 undecidable manual P 95 0.1169 129 0.19 49
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.NRCA.HHE. ML:1.8 0.000615 0.18 AML other m 2021-01-20T18:39:59.69
IV.NRCA.HHN. ML:1.6 0.0004525 0.12 AML other m 2021-01-20T18:39:59.69
IV.MTRA.EHE. ML:1.4 0.000272 0.34 AML other m 2021-01-20T18:40:00.23
IV.MTRA.EHN. ML:1.4 0.000255 0.3 AML other m 2021-01-20T18:40:00.51
IV.SMA1.EHE. ML:1 9.21E-5 1.12 AML other m 2021-01-20T18:40:01.23
IV.SMA1.EHN. ML:0.9 7.085E-5 0.9 AML other m 2021-01-20T18:40:01.37
IV.LNSS.HHE. ML:1.2 0.0001027 0.88 AML other m 2021-01-20T18:40:04.59
IV.RM33.EHN. ML:1.2 7.295E-5 0.74 AML other m 2021-01-20T18:40:04.33
IV.FDMO.HHN. ML:0.9 3.555E-5 0.92 AML other m 2021-01-20T18:40:05.82
IV.FDMO.HHE. ML:0.9 3.545E-5 0.24 AML other m 2021-01-20T18:40:05.37
IV.LNSS.HHN. ML:1.1 7.395E-5 0.64 AML other m 2021-01-20T18:40:05.69
IV.TERO.HHN. ML:1.2 7.205E-5 0.3 AML other m 2021-01-20T18:40:05.80
IV.RM33.EHE. ML:1.2 8.285E-5 1.04 AML other m 2021-01-20T18:40:05.81
IV.CESI.HHN. ML:1.3 7.24E-5 1.62 AML other m 2021-01-20T18:40:06.94
IV.CESI.HHE. ML:1.2 5.37E-5 1.04 AML other m 2021-01-20T18:40:07.92
IV.CSP1.EHN. ML:1.6 0.0001449 0.52 AML other m 2021-01-20T18:40:07.91
IV.CSP1.EHE. ML:1.3 7.365E-5 1.22 AML other m 2021-01-20T18:40:07.75
IV.TERO.HHE. ML:1.1 4.94E-5 1.54 AML other m 2021-01-20T18:40:07.03
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