Earthquake with magnitude of Md 2.1 on date 17-07-1987 and time 11:57:00 (Italy) in region 4 km SW Santa Sofia (FC)

A magnitude Md 2.1 earthquake occured in region: 4 km SW Santa Sofia (FC), on

  • 17-07-1987 09:57:00 (UTC)
  • 17-07-1987 11:57:00 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.9300, 11.8720 at 6 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
Santa Sofia FC 4 4136 4136
Galeata FC 8 2516 6652
Premilcuore FC 9 799 7451
Civitella di Romagna FC 10 3786 11237
Bagno di Romagna FC 12 6026 17263
Portico e San Benedetto FC 13 756 18019
Rocca San Casciano FC 15 1910 19929
Verghereto FC 18 1907 21836
Tredozio FC 20 1212 23048
Pratovecchio Stia AR 20 5845 28893

Municipalities with at least 50000 inhabitants

An earthquake occurred to
35 Km SW of Forlì (117913 inhabitants)
38 Km SW of Cesena (96758 inhabitants)
40 Km S of Faenza (58541 inhabitants)
49 Km S of Imola (69797 inhabitants)
51 Km N of Arezzo (99543 inhabitants)
52 Km E of Firenze (382808 inhabitants)
58 Km W of Rimini (147750 inhabitants)
59 Km E of Scandicci (50609 inhabitants)
60 Km SW of Ravenna (159116 inhabitants)
62 Km E of Prato (191150 inhabitants)
76 Km SE of Bologna (386663 inhabitants)
76 Km E of Pistoia (90315 inhabitants)
81 Km NE of Siena (53903 inhabitants)
84 Km W of Pesaro (94582 inhabitants)
93 Km W 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 2.1 1987-07-17
09:57:00
43.93 11.872 6 2013-07-15
08:40:51
Bollettino Sismico Italiano INGV 52449
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-07-17 09:57:00 ± 0.216
Latitude 43.9300 ± 0.0125
Longitude 11.8720 ± 0.0100
Depth (km) 6 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 52449

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) 1606.6
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 263
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) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00008
Epicentral distance of station farthest from the epicenter (degree) 0.00931
Number of stations at which the event was observed 4
Number of stations from which data was used for origin computation 4
Magnitude information

Md:2.1

Field Value
Value 2.1
Uncertainty
Num. used stations 3
Type of magnitude Md
Reference to an origin 52449
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:50:40
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.ASS.Z. 1987-07-17T09:57:36.50 10.0 undecidable manual SG 146 1.0323 0.31 0.2
--.ASS.Z. 1987-07-17T09:57:21.00 10.0 undecidable manual PG 146 1.0323 -0.04 1.2
--.CRE.Z. 1987-07-17T09:57:12.97 10.0 undecidable manual SG 169 0.3108 0.29 0.3
--.CRE.Z. 1987-07-17T09:57:07.20 10.0 undecidable manual PG 169 0.3108 -0.44 0.5
--.PGD.Z. 1987-07-17T09:57:05.55 10.0 undecidable manual SG 243 0.1221 0.04 0.9
--.PGD.Z. 1987-07-17T09:57:03.30 10.0 undecidable manual PG 243 0.1221 -0.02 2.3
--.SS9.Z. 1987-07-17T09:57:02.49 10.0 undecidable manual SG 238 0.0111 -0.13 0.9
--.SS9.Z. 1987-07-17T09:57:01.80 10.0 undecidable manual PG 238 0.0111 0.14 1.7
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download