Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.8 on date 20-04-2013 and time 23:50:31 (Italy) in region 4 km E Città di Castello (PG)

A magnitude ML 0.8 earthquake occured in region: 4 km E Città di Castello (PG), on

  • 20-04-2013 21:50:31 (UTC)
  • 20-04-2013 23:50:31 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.4520, 12.2940 at 10 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

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
Città di Castello PG 5 39913 39913
Montone PG 10 1680 41593
Monte Santa Maria Tiberina PG 11 1183 42776
Pietralunga PG 12 2111 44887
San Giustino PG 14 11297 56184
Monterchi AR 15 1757 57941
Citerna PG 15 3531 61472
Apecchio PU 16 1882 63354
Umbertide PG 16 16681 80035
Sansepolcro AR 18 15884 95919

Municipalities with at least 50000 inhabitants

An earthquake occurred to
33 Km E of Arezzo (99543 inhabitants)
39 Km N of Perugia (166134 inhabitants)
64 Km NW of Foligno (57155 inhabitants)
71 Km SW of Rimini (147750 inhabitants)
71 Km SW of Pesaro (94582 inhabitants)
73 Km SW of Fano (60888 inhabitants)
76 Km S of Cesena (96758 inhabitants)
79 Km E of Siena (53903 inhabitants)
88 Km S of Forlì (117913 inhabitants)
91 Km E of Firenze (382808 inhabitants)
96 Km E of Scandicci (50609 inhabitants)
99 Km SE of Faenza (58541 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
Bulletin
Rev1000 		ML 0.8 2013-04-20
21:50:31		 43.4517 12.294 10 2015-01-20
11:25:00		 Bollettino Sismico Italiano INGV 3308431
Reviewed
Rev100 		ML 0.8 2013-04-20
21:50:31		 43.4517 12.294 10 2014-10-21
12:08:56		 Sala Sismica INGV-Roma 3244391
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2013-04-20 21:50:31 ± 0.12
Latitude 43.4517 ± 0.0063
Longitude 12.2940 ± 0.0124
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 3308431

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1036
Semi-minor axis of confidence ellipse (meter) 527
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 63
Circular confidence region, given by single value of horizontal uncertainty (meter) 1040.0
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 11
Number of defining phases 11
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.27
Epicentral distance of station closest to the epicenter (degree) 0.07824
Epicentral distance of station farthest from the epicenter (degree) 0.25721
Number of stations at which the event was observed 6
Number of stations from which data was used for origin computation 6
Magnitudes information

ML:0.8

Field Value
Value 0.8
Uncertainty 0.1
Num. used stations 2
Type of magnitude ML
Reference to an origin 3308431
Agency INGV
Autore Manually reviewed by Franco Mele
Time of creation (UTC) 2015-01-15 12:55:16

ML:0.8

Field Value
Value 0.8
Uncertainty 0.1
Num. used stations 2
Type of magnitude ML
Reference to an origin 3244391
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2013-04-20 22:48:08
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.ATTE.HHZ. 2013-04-20T21:50:41.58 0.1 undecidable manual S 170 28.5492 -0.34 93
IV.PARC.HHZ. 2013-04-20T21:50:40.09 0.1 undecidable manual S 348 22.2555 -0.04 100
IV.PIEI.HHZ. 2013-04-20T21:50:40.26 0.3 undecidable manual S 64 21.5673 0.37 70
IV.ATTE.HHZ. 2013-04-20T21:50:37.84 0.1 undecidable manual P 170 28.5492 0.28 94
IV.ATVO.HHZ. 2013-04-20T21:50:37.16 0.3 undecidable manual S 130 11.877 0.09 76
IV.PARC.HHZ. 2013-04-20T21:50:36.44 0.1 undecidable manual P 348 22.2555 -0.1 99
IV.PIEI.HHZ. 2013-04-20T21:50:36.49 0.6 undecidable manual P 64 21.5673 0.09 50
IV.ATMI.HHZ. 2013-04-20T21:50:35.24 0.3 undecidable manual P 189 13.1757 0.27 73
IV.ATPI.EHZ. 2013-04-20T21:50:35.84 0.1 undecidable manual S 91 8.6802 -0.44 94
IV.ATVO.HHZ. 2013-04-20T21:50:34.89 0.3 negative manual P 130 11.877 0.12 75
IV.ATPI.EHZ. 2013-04-20T21:50:34.19 1.0 undecidable manual P 91 8.6802 -0.13 25
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.ATMI.HHE. ML:0.8 0.0000658 0.3 AML other m 2013-04-20T21:50:37.64
IV.ATMI.HHN. ML:0.9 0.00008060000000000001 0.76 AML other m 2013-04-20T21:50:41.59
IV.PARC.HHN. ML:0.8 0.0000406 1.58 AML other m 2013-04-20T21:50:42.39
IV.PARC.HHE. ML:0.7 0.000036315 1.58 AML other m 2013-04-20T21:50:43.22
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