Earthquake with magnitude of Md 2.1 on date 17-10-1987 and time 02:35:09 (Italy) in region 6 km E Marradi (FI)

A magnitude Md 2.1 earthquake occured in region: 6 km E Marradi (FI), on

  • 17-10-1987 01:35:09 (UTC)
  • 17-10-1987 02:35:09 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 44.0980, 11.6760 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
Marradi FI 6 3139 3139
Tredozio FC 6 1212 4351
Palazzuolo sul Senio FI 10 1154 5505
Modigliana FC 12 4560 10065
Portico e San Benedetto FC 12 756 10821
Rocca San Casciano FC 14 1910 12731
Casola Valsenio RA 15 2617 15348
Premilcuore FC 16 799 16147
Brisighella RA 16 7639 23786
Dovadola FC 17 1653 25439
Castel del Rio BO 19 1246 26685
San Godenzo FI 20 1167 27852

Municipalities with at least 50000 inhabitants

An earthquake occurred to
27 Km SW of Faenza (58541 inhabitants)
29 Km S of Imola (69797 inhabitants)
32 Km W of Forlì (117913 inhabitants)
46 Km W of Cesena (96758 inhabitants)
50 Km NE of Firenze (382808 inhabitants)
52 Km SE of Bologna (386663 inhabitants)
52 Km E of Prato (191150 inhabitants)
55 Km NE of Scandicci (50609 inhabitants)
55 Km SW of Ravenna (159116 inhabitants)
63 Km E of Pistoia (90315 inhabitants)
71 Km W of Rimini (147750 inhabitants)
72 Km N of Arezzo (99543 inhabitants)
82 Km S of Ferrara (133155 inhabitants)
85 Km SE of Modena (184973 inhabitants)
91 Km NE of Siena (53903 inhabitants)
98 Km E of Lucca (89046 inhabitants)
99 Km SE of Carpi (70699 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 1987-10-17
01:35:09
44.098 11.676 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 57099
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1987-10-17 01:35:09 ± 0.338
Latitude 44.0980 ± 0.0138
Longitude 11.6760 ± 0.0261
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 57099

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) 2589.9
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 332
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) 0.2
Epicentral distance of station closest to the epicenter (degree) 0.00194
Epicentral distance of station farthest from the epicenter (degree) 0.00461
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:2.1

Field Value
Value 2.1
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 57099
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:54:46
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.CRE.Z. 1987-10-17T01:35:27.89 10.0 undecidable manual SG 157 0.5106 -0.1 0.7
--.CRE.Z. 1987-10-17T01:35:19.76 10.0 undecidable manual PG 157 0.5106 -0.39 0.5
--.SS9.Z. 1987-10-17T01:35:18.56 10.0 undecidable manual SG 144 0.2109 0.2 0.6
--.PGD.Z. 1987-10-17T01:35:18.50 10.0 undecidable manual SG 171 0.222 -0.1 0.9
--.PGD.Z. 1987-10-17T01:35:15.00 10.0 undecidable manual PG 171 0.222 0.27 1.2
--.SS9.Z. 1987-10-17T01:35:14.67 10.0 undecidable manual PG 144 0.2109 0.08 2.1
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