Earthquake with magnitude of Md 2.5 on date 11-12-1985 and time 02:57:47 (Italy) in region 4 km E Londa (FI)

A magnitude Md 2.5 earthquake occured in region: 4 km E Londa (FI), on

  • 11-12-1985 01:57:47 (UTC)
  • 11-12-1985 02:57:47 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.87, 11.62 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
Londa FI 5 1840 1840
San Godenzo FI 7 1167 3007
Dicomano FI 8 5515 8522
Rufina FI 12 7346 15868
Pratovecchio Stia AR 12 5845 21713
Montemignaio AR 14 566 22279
Pelago FI 14 7660 29939
Vicchio FI 15 8044 37983
Castel San Niccolò AR 16 2707 40690
Premilcuore FC 17 799 41489
Pontassieve FI 18 20603 62092
Poppi AR 20 6160 68252

Municipalities with at least 50000 inhabitants

An earthquake occurred to
31 Km E of Firenze (382808 inhabitants)
37 Km E of Scandicci (50609 inhabitants)
42 Km E of Prato (191150 inhabitants)
49 Km NW of Arezzo (99543 inhabitants)
51 Km SW of Faenza (58541 inhabitants)
52 Km SW of Forlì (117913 inhabitants)
55 Km S of Imola (69797 inhabitants)
57 Km E of Pistoia (90315 inhabitants)
58 Km SW of Cesena (96758 inhabitants)
65 Km NE of Siena (53903 inhabitants)
73 Km SE of Bologna (386663 inhabitants)
77 Km SW of Ravenna (159116 inhabitants)
79 Km W of Rimini (147750 inhabitants)
90 Km E of Lucca (89046 inhabitants)
99 Km E of Pisa (89158 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
Rev 1000 Md 2.5 1985-12-11
01:57:47
43.87 11.62 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 17839
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1985-12-11 01:57:47 ± 0.321
Latitude 43.87 ± 0.03
Longitude 11.62 ± 0.02
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 17839

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) 4119.3
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 185
Number of associated phases, regardless of their use for origin computation 8
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.4
Epicentral distance of station closest to the epicenter (degree) 0.00251
Epicentral distance of station farthest from the epicenter (degree) 0.00915
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitude information

Md:2.5

Field Value
Value 2.5
Uncertainty
Num. used stations 4
Type of magnitude Md
Reference to an origin 17839
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:20:39
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.PS9.Z. 1985-12-11T01:58:15.50 10.0 undecidable manual SG 259 0.0072 -0.02 0.6
--.BD1.Z. 1985-12-11T01:58:13.50 10.0 undecidable manual SG 284 0.0068 -0.64 0.3
--.ARV.Z. 1985-12-11T01:58:08.00 10.0 undecidable manual PG 110 0.0091 0.19 1.4
--.PS9.Z. 1985-12-11T01:58:05.00 10.0 undecidable manual PG 259 0.0072 1.22 0.3
--.BD1.Z. 1985-12-11T01:58:03.00 10.0 undecidable manual PG 284 0.0068 0.02 1.8
--.CRE.Z. 1985-12-11T01:58:01.00 10.0 undecidable manual SG 135 0.0031 0.35 0.7
--.CRE.Z. 1985-12-11T01:57:54.50 10.0 undecidable manual PG 135 0.0031 -0.69 1
--.FIR.Z. 1985-12-11T01:57:54.00 10.0 undecidable manual PG 250 0.0025 -0.05 1.9
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