Earthquake with magnitude of Md 2.2 on date 18-08-1991 and time 13:17:47 (UTC) in region 3 km NW Castelnuovo di Val di Cecina (PI)

A magnitude Md 2.2 earthquake occured in region: 3 km NW Castelnuovo di Val di Cecina (PI), on

  • 18-08-1991 13:17:47 (UTC)
  • 18-08-1991 15:17:47 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.224, 10.881 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Castelnuovo di Val di Cecina PI 3 2231 2231
Pomarance PI 9 5897 8128
Monterotondo Marittimo GR 9 1371 9499
Radicondoli SI 14 914 10413
Monteverdi Marittimo PI 14 758 11171
Montieri GR 15 1204 12375
Chiusdino SI 19 1903 14278
Casole d'Elsa SI 19 3897 18175
Massa Marittima GR 19 8375 26550
Volterra PI 20 10519 37069

Municipalities with at least 50000 inhabitants

An earthquake occurred to
38 Km W of Siena (53903 inhabitants)
55 Km NW of Grosseto (82087 inhabitants)
59 Km SE of Livorno (159219 inhabitants)
64 Km SW of Scandicci (50609 inhabitants)
67 Km SE of Pisa (89158 inhabitants)
68 Km SW of Firenze (382808 inhabitants)
75 Km S of Prato (191150 inhabitants)
76 Km SE of Lucca (89046 inhabitants)
79 Km S of Pistoia (90315 inhabitants)
85 Km W of Arezzo (99543 inhabitants)
88 Km SE of Viareggio (62467 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 2.2
ML-VAX 2.0
1991-08-18
13:17:47
43.224 10.881 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 147659
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-08-18 13:17:47 ± 0.305
Latitude 43.2240 ± 0.0170
Longitude 10.8810 ± 0.0423
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 147659

Uncertainty

Field Value
Preferred uncertainty description horizontal uncertainty
Semi-major axis of confidence ellipse (meter)
Semi-minor axis of confidence ellipse (meter)
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi)
Circular confidence region, given by single value of horizontal uncertainty (meter) 3912.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 166
Number of associated phases, regardless of their use for origin computation 10
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.5
Epicentral distance of station closest to the epicenter (degree) 0.00502
Epicentral distance of station farthest from the epicenter (degree) 0.00874
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitudes information

Md:2.2

Field Value
Value 2.2
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 147659
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:17:49

ML:2

Field Value
Value 2
Uncertainty
Num. used stations 2
Type of magnitude ML
Reference to an origin 147659
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 13:07:13
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.SFI.Z. 1991-08-18T13:18:19.99 10.0 undecidable manual SG 45 0.0087 -0.97 0.3
--.BDI.Z. 1991-08-18T13:18:16.21 10.0 undecidable manual SG 346 0.0077 -1.1 0.2
--.CRE.Z. 1991-08-18T13:18:16.70 10.0 undecidable manual SG 62 0.0078 -1.54 0.1
--.MAO.Z. 1991-08-18T13:18:15.22 10.0 undecidable manual SG 165 0.0074 -1.11 0.2
--.SFI.Z. 1991-08-18T13:18:08.70 10.0 undecidable manual PG 45 0.0087 1.16 0.5
--.PII.Z. 1991-08-18T13:18:06.84 10.0 undecidable manual SG 332 0.005 -0.77 0.4
--.CRE.Z. 1991-08-18T13:18:05.49 10.0 undecidable manual PG 62 0.0078 0.51 1.4
--.BDI.Z. 1991-08-18T13:18:05.28 10.0 undecidable manual PG 346 0.0077 0.47 1.4
--.MAO.Z. 1991-08-18T13:18:04.27 10.0 positive manual PG 165 0.0074 0.03 3.6
--.PII.Z. 1991-08-18T13:17:59.19 10.0 undecidable manual PG 332 0.005 -0.01 1.8
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
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