Earthquake with magnitude of Md 2.0 on date 20-07-1991 and time 09:19:07 (UTC) in region 4 km S Bolognola (MC)

A magnitude Md 2.0 earthquake occured in region: 4 km S Bolognola (MC), on

  • 20-07-1991 09:19:07 (UTC)
  • 20-07-1991 11:19:07 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.96, 13.23 at 20 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
Bolognola MC 4 142 142
Ussita MC 8 444 586
Acquacanina MC 9 121 707
Montefortino FM 9 1178 1885
Castelsantangelo sul Nera MC 10 281 2166
Sarnano MC 10 3264 5430
Montemonaco AP 10 604 6034
Amandola FM 10 3629 9663
Fiastra MC 10 559 10222
Visso MC 12 1107 11329
Fiordimonte MC 14 202 11531
Gualdo MC 15 815 12346
Comunanza AP 15 3166 15512
Montegallo AP 16 523 16035
Pievebovigliana MC 17 866 16901
Cessapalombo MC 17 512 17413
Pieve Torina MC 17 1458 18871
San Ginesio MC 18 3498 22369
Smerillo FM 18 365 22734
Preci PG 18 724 23458
Monte San Martino MC 19 765 24223
Montefalcone Appennino FM 19 424 24647
Penna San Giovanni MC 19 1108 25755
Monte Cavallo MC 19 145 25900
Camporotondo di Fiastrone MC 19 563 26463
Caldarola MC 20 1823 28286
Palmiano AP 20 196 28482

Municipalities with at least 50000 inhabitants

An earthquake occurred to
43 Km E of Foligno (57155 inhabitants)
51 Km NW of Teramo (54892 inhabitants)
65 Km NE of Terni (111501 inhabitants)
69 Km N of L'Aquila (69753 inhabitants)
71 Km E of Perugia (166134 inhabitants)
77 Km SW of Ancona (100861 inhabitants)
90 Km NW of Montesilvano (53738 inhabitants)
97 Km NW of Pescara (121014 inhabitants)
100 Km S of Fano (60888 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 2.0
ML-VAX 1.7
1991-07-20
09:19:07
42.96 13.23 20 2013-07-15
08:40:51
Bollettino Sismico Italiano INGV 145889
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-07-20 09:19:07 ± 0.339
Latitude 42.96 ± 0.02
Longitude 13.23 ± 0.02
Depth (km) 20 ± 3 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 145889

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) 2945.8
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 142
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) 0.4
Epicentral distance of station closest to the epicenter (degree) 0.00016
Epicentral distance of station farthest from the epicenter (degree) 0.00518
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

Field Value
Value 2
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 145889
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:16:11

ML:1.7

Field Value
Value 1.7
Uncertainty
Num. used stations 1
Type of magnitude ML
Reference to an origin 145889
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
--.ARV.Z. 1991-07-20T09:19:28.50 10.0 undecidable manual SG 338 0.0052 0.24 0.6
--.ASS.Z. 1991-07-20T09:19:23.39 10.0 undecidable manual SG 283 0.0039 -0.48 0.5
--.ARV.Z. 1991-07-20T09:19:20.50 10.0 undecidable manual PG 338 0.0052 1 0.4
--.ALP.Z. 1991-07-20T09:19:19.73 10.0 undecidable manual SG 126 0.0027 -0.16 0.9
--.CIO.Z. 1991-07-20T09:19:17.70 10.0 undecidable manual SG 344 0.0021 -1.03 0.2
--.ASS.Z. 1991-07-20T09:19:16.81 10.0 undecidable manual PG 283 0.0039 -0.16 1.8
--.ALP.Z. 1991-07-20T09:19:14.37 10.0 undecidable manual PG 126 0.0027 -0.3 2
--.RMF.Z. 1991-07-20T09:19:14.19 10.0 undecidable manual SG 246 0.0002 0.27 0.8
--.CIO.Z. 1991-07-20T09:19:13.50 10.0 undecidable manual PG 344 0.0021 -0.59 1.4
--.RMF.Z. 1991-07-20T09:19:11.80 10.0 undecidable manual PG 246 0.0002 0.57 1.4
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
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