Earthquake with magnitude of Md 1.9 on date 22-04-1985 and time 12:00:16 (Italy) in region 8 km W Arquata del Tronto (AP)

A magnitude Md 1.9 earthquake occured in region: 8 km W Arquata del Tronto (AP), on

  • 22-04-1985 10:00:16 (UTC)
  • 22-04-1985 12:00:16 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.8, 13.2 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
Arquata del Tronto AP 8 1178 1178
Norcia PG 9 4957 6135
Castelsantangelo sul Nera MC 12 281 6416
Accumoli RI 12 667 7083
Montegallo AP 12 523 7606
Montemonaco AP 16 604 8210
Preci PG 16 724 8934
Acquasanta Terme AP 17 2916 11850
Ussita MC 17 444 12294
Cascia PG 18 3217 15511
Visso MC 18 1107 16618
Amatrice RI 20 2657 19275
Cittareale RI 20 482 19757
Montefortino FM 20 1178 20935

Municipalities with at least 50000 inhabitants

An earthquake occurred to
44 Km W of Teramo (54892 inhabitants)
44 Km E of Foligno (57155 inhabitants)
52 Km NW of L'Aquila (69753 inhabitants)
52 Km NE of Terni (111501 inhabitants)
75 Km E of Perugia (166134 inhabitants)
84 Km W of Montesilvano (53738 inhabitants)
91 Km W of Pescara (121014 inhabitants)
93 Km NW of Chieti (51815 inhabitants)
95 Km S of Ancona (100861 inhabitants)
97 Km NE of Guidonia Montecelio (88673 inhabitants)
98 Km NE of Tivoli (56533 inhabitants)
99 Km E of Viterbo (67173 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 1.9 1985-04-22
10:00:16
42.8 13.2 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 5269
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1985-04-22 10:00:16 ± 0.434
Latitude 42.80 ± 0.02
Longitude 13.20 ± 0.04
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 5269

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) 4017.8
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 132
Number of associated phases, regardless of their use for origin computation 6
Number of defining phases 6
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.9
Epicentral distance of station closest to the epicenter (degree) 0.00235
Epicentral distance of station farthest from the epicenter (degree) 0.00356
Number of stations at which the event was observed 3
Number of stations from which data was used for origin computation 3
Magnitude information

Md:1.9

Field Value
Value 1.9
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 5269
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:09:45
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.CM2.Z. 1985-04-22T10:00:32.30 10.0 undecidable manual SG 353 0.0036 0.95 0.6
--.PO9.Z. 1985-04-22T10:00:29.00 10.0 undecidable manual SG 221 0.0026 1.04 0.4
--.ALP.Z. 1985-04-22T10:00:28.10 10.0 undecidable manual SG 93 0.0023 0.92 0.7
--.CM2.Z. 1985-04-22T10:00:24.30 10.0 undecidable manual PG 353 0.0036 -0.83 2.3
--.PO9.Z. 1985-04-22T10:00:22.00 10.0 undecidable manual PG 221 0.0026 -1.18 0.9
--.ALP.Z. 1985-04-22T10:00:21.80 10.0 undecidable manual PG 93 0.0023 -0.93 1.2
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Download
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