Earthquake with magnitude of ML 1.6 on date 23-04-2009 and time 09:45:27 (Italy) in region 4 km SE Radicofani (SI)

A magnitude ML 1.6 earthquake occured in region: 4 km SE Radicofani (SI), on

  • 23-04-2009 07:45:27 (UTC)
  • 23-04-2009 09:45:27 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.8650, 11.7820 at 21 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Radicofani SI 4 1097 1097
Piancastagnaio SI 8 4230 5327
San Casciano dei Bagni SI 8 1632 6959
Abbadia San Salvatore SI 9 6444 13403
Castell'Azzara GR 12 1476 14879
Proceno VT 13 557 15436
Cetona SI 15 2755 18191
Acquapendente VT 15 5506 23697
Sarteano SI 16 4717 28414
Santa Fiora GR 16 2622 31036
Allerona TR 17 1794 32830
Fabro TR 19 2876 35706
Onano VT 19 995 36701
Seggiano GR 20 961 37662
Arcidosso GR 20 4285 41947

Municipalities with at least 50000 inhabitants

An earthquake occurred to
56 Km E of Grosseto (82087 inhabitants)
56 Km W of Perugia (166134 inhabitants)
56 Km NW of Viterbo (67173 inhabitants)
62 Km SE of Siena (53903 inhabitants)
68 Km S of Arezzo (99543 inhabitants)
76 Km W of Foligno (57155 inhabitants)
78 Km W of Terni (111501 inhabitants)
86 Km N of Civitavecchia (52991 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
Md 1.9
ML 1.6
2009-04-23
07:45:27
42.865 11.782 21 2014-10-21
12:27:13
Bollettino Sismico Italiano INGV 830059
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2009-04-23 07:45:27 ± 0.09
Latitude 42.8650 ± 0.0090
Longitude 11.7820 ± 0.0160
Depth (km) 21 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-SISPICK
Event type earthquake
Origin ID 830059

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1802
Semi-minor axis of confidence ellipse (meter) 253
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 126
Circular confidence region, given by single value of horizontal uncertainty (meter) 1640.1
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 263
Number of associated phases, regardless of their use for origin computation 7
Number of defining phases 5
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.05
Epicentral distance of station closest to the epicenter (degree) 0.00000
Epicentral distance of station farthest from the epicenter (degree) 0.25181
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 3
Magnitudes information

ML:1.6

Field Value
Value 1.6
Uncertainty 0.3
Num. used stations
Type of magnitude ML
Reference to an origin 830059
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-05 15:44:16

Md:1.9

Field Value
Value 1.9
Uncertainty 0.1
Num. used stations
Type of magnitude Md
Reference to an origin 830059
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-05 15:44:16
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.MGAB.HHE. 2009-04-23T07:45:37.95 0.6 undecidable manual Sg 79 27.3504 0.031 49
IV.SACS.HHZ. 2009-04-23T07:45:34.64 0.3 undecidable manual Sg 100 10.4784 -0.019 75
IV.MGAB.HHE. 2009-04-23T07:45:33.45 0.1 undecidable manual Pg 79 27.3504 -0.026 97
IV.LATE.HHZ. 2009-04-23T07:45:33.56 0.3 undecidable manual Pg 176 27.9498 0 73
IV.SACS.HHZ. 2009-04-23T07:45:31.62 0.1 undecidable manual Pg 100 10.4784 0.026 100
IV.FIU.EHZ. 2009-04-23T07:45:24.15 10.0 undecidable manual Pg 0 0 0
IV.FAVR.SHZ. 2009-04-23T07:45:12.88 10.0 undecidable manual Pg 0 0 0
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