Earthquake with magnitude of Md 2.4 on date 23-07-1991 and time 11:41:16 (Italy) in region 4 km NE Borbona (RI)

A magnitude Md 2.4 earthquake occured in region: 4 km NE Borbona (RI), on

  • 23-07-1991 09:41:16 (UTC)
  • 23-07-1991 11:41:16 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.55, 13.16 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
Borbona RI 5 617 617
Posta RI 6 694 1311
Montereale AQ 7 2581 3892
Cittareale RI 8 482 4374
Cagnano Amiterno AQ 11 1369 5743
Capitignano AQ 12 665 6408
Micigliano RI 14 127 6535
Amatrice RI 14 2657 9192
Barete AQ 14 737 9929
Antrodoco RI 16 2588 12517
Leonessa RI 16 2435 14952
Pizzoli AQ 16 4326 19278
Campotosto AQ 17 542 19820
Borgo Velino RI 18 972 20792
Accumoli RI 18 667 21459
Castel Sant'Angelo RI 20 1308 22767

Municipalities with at least 50000 inhabitants

An earthquake occurred to
29 Km NW of L'Aquila (69753 inhabitants)
42 Km E of Terni (111501 inhabitants)
46 Km W of Teramo (54892 inhabitants)
59 Km SE of Foligno (57155 inhabitants)
71 Km NE of Guidonia Montecelio (88673 inhabitants)
71 Km NE of Tivoli (56533 inhabitants)
81 Km W of Montesilvano (53738 inhabitants)
85 Km W of Chieti (51815 inhabitants)
87 Km W of Pescara (121014 inhabitants)
88 Km E of Viterbo (67173 inhabitants)
89 Km SE of Perugia (166134 inhabitants)
92 Km NE of Roma (2864731 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 2.4 1991-07-23
09:41:16
42.55 13.16 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 146039
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-07-23 09:41:16 ± 0.154
Latitude 42.55 ± 0.01
Longitude 13.16 ± 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 146039

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) 1566.9
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 95
Number of associated phases, regardless of their use for origin computation 15
Number of defining phases 15
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.3
Epicentral distance of station closest to the epicenter (degree) 0.00235
Epicentral distance of station farthest from the epicenter (degree) 0.00866
Number of stations at which the event was observed 8
Number of stations from which data was used for origin computation 8
Magnitude information

Md:2.4

Field Value
Value 2.4
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 146039
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:16:20
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.ARV.Z. 1991-07-23T09:41:50.00 10.0 undecidable manual SG 350 0.0087 0.75 0.1
--.CIO.Z. 1991-07-23T09:41:38.10 10.0 undecidable manual SG 358 0.0057 -0.96 0.1
--.ASS.Z. 1991-07-23T09:41:38.81 10.0 undecidable manual SG 324 0.0057 0.08 0.7
--.ARV.Z. 1991-07-23T09:41:35.50 10.0 undecidable manual PG 350 0.0087 0.15 1.4
--.SDI.Z. 1991-07-23T09:41:35.50 10.0 undecidable manual PG 150 0.0087 0.14 1.4
--.RMF.Z. 1991-07-23T09:41:31.37 10.0 undecidable manual SG 4 0.0036 -0.01 0.8
--.ALP.Z. 1991-07-23T09:41:30.19 10.0 undecidable manual SG 51 0.0033 -0.2 0.7
--.ASS.Z. 1991-07-23T09:41:29.88 10.0 undecidable manual PG 324 0.0057 0.6 0.7
--.MNS.Z. 1991-07-23T09:41:29.50 10.0 undecidable manual SG 245 0.0035 -1.34 0
--.CIO.Z. 1991-07-23T09:41:28.96 10.0 undecidable manual PG 358 0.0057 -0.51 1
--.AQU.Z. 1991-07-23T09:41:26.50 10.0 undecidable manual SG 137 0.0023 -0.18 0.7
--.MNS.Z. 1991-07-23T09:41:25.00 10.0 undecidable manual PG 245 0.0035 0.27 1.7
--.RMF.Z. 1991-07-23T09:41:25.10 10.0 undecidable manual PG 4 0.0036 0.07 2
--.ALP.Z. 1991-07-23T09:41:24.30 10.0 undecidable manual PG 51 0.0033 -0.17 1.9
--.AQU.Z. 1991-07-23T09:41:22.50 10.0 undecidable manual PG 137 0.0023 0.18 1.8
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
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