Earthquake with magnitude of Md 2.3 on date 31-07-1985 and time 15:33:58 (UTC) in region 4 km SW Fiastra (MC)

A magnitude Md 2.3 earthquake occured in region: 4 km SW Fiastra (MC), on

  • 31-07-1985 15:33:58 (UTC)
  • 31-07-1985 17:33:58 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.01, 13.13 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
Fiastra MC 4 559 559
Acquacanina MC 4 121 680
Fiordimonte MC 4 202 882
Pievebovigliana MC 7 866 1748
Pieve Torina MC 7 1458 3206
Ussita MC 7 444 3650
Bolognola MC 8 142 3792
Visso MC 9 1107 4899
Muccia MC 11 915 5814
Monte Cavallo MC 11 145 5959
Castelsantangelo sul Nera MC 13 281 6240
Sarnano MC 14 3264 9504
Camerino MC 15 6974 16478
Cessapalombo MC 15 512 16990
Serravalle di Chienti MC 16 1070 18060
Caldarola MC 16 1823 19883
Preci PG 16 724 20607
Camporotondo di Fiastrone MC 18 563 21170
Gualdo MC 18 815 21985
Amandola FM 19 3629 25614
San Ginesio MC 19 3498 29112
Montefortino FM 19 1178 30290
Serrapetrona MC 19 966 31256
Belforte del Chienti MC 19 1886 33142

Municipalities with at least 50000 inhabitants

An earthquake occurred to
35 Km E of Foligno (57155 inhabitants)
61 Km NW of Teramo (54892 inhabitants)
61 Km E of Perugia (166134 inhabitants)
64 Km NE of Terni (111501 inhabitants)
75 Km SW of Ancona (100861 inhabitants)
77 Km N of L'Aquila (69753 inhabitants)
93 Km S of Fano (60888 inhabitants)
100 Km NW of Montesilvano (53738 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 2.3 1985-07-31
15:33:58
43.01 13.13 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 11129
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1985-07-31 15:33:58 ± 0.261
Latitude 43.01 ± 0.01
Longitude 13.13 ± 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 11129

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) 2524
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 93
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) 0.8
Epicentral distance of station closest to the epicenter (degree) 0.00162
Epicentral distance of station farthest from the epicenter (degree) 0.00575
Number of stations at which the event was observed 6
Number of stations from which data was used for origin computation 6
Magnitude information

Md:2.3

Field Value
Value 2.3
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 11129
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:14:36
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.AR1.Z. 1985-07-31T15:34:17.50 10.0 undecidable manual SG 344 0.0045 1.02 0.3
--.PO9.Z. 1985-07-31T15:34:16.00 10.0 undecidable manual SG 197 0.004 1.1 0.5
--.ALP.Z. 1985-07-31T15:34:12.40 10.0 undecidable manual SG 125 0.0035 -0.48 1
--.AM1.Z. 1985-07-31T15:34:11.60 10.0 undecidable manual PG 32 0.0057 0.33 1.5
--.AS1.Z. 1985-07-31T15:34:10.50 10.0 undecidable manual SG 278 0.0032 -1.04 0.6
--.PO9.Z. 1985-07-31T15:34:09.00 10.0 undecidable manual PG 197 0.004 1.11 0.9
--.AR1.Z. 1985-07-31T15:34:09.50 10.0 undecidable manual PG 344 0.0045 0.7 1.3
--.ALP.Z. 1985-07-31T15:34:06.00 10.0 undecidable manual PG 125 0.0035 -0.72 1.3
--.CM2.Z. 1985-07-31T15:34:06.50 10.0 undecidable manual SG 2 0.0016 0.43 1.1
--.AS1.Z. 1985-07-31T15:34:05.00 10.0 undecidable manual PG 278 0.0032 -0.95 1.1
--.CM2.Z. 1985-07-31T15:34:02.10 10.0 undecidable manual PG 2 0.0016 -0.69 1.5
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
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