Earthquake with magnitude of Md 2.0 on date 25-04-1986 and time 21:57:41 (Italy) in region 6 km E Masone (GE)

A magnitude Md 2.0 earthquake occured in region: 6 km E Masone (GE), on

  • 25-04-1986 19:57:41 (UTC)
  • 25-04-1986 21:57:41 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.5180, 8.7880 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
Masone GE 6 3679 3679
Campo Ligure GE 8 2955 6634
Mele GE 9 2725 9359
Campomorone GE 9 6996 16355
Ceranesi GE 9 3875 20230
Mignanego GE 10 3675 23905
Rossiglione GE 11 2779 26684
Fraconalto AL 11 336 27020
Serra Riccò GE 12 7885 34905
Voltaggio AL 12 738 35643
Tiglieto GE 13 546 36189
Mornese AL 14 737 36926
Casaleggio Boiro AL 14 372 37298
Busalla GE 14 5563 42861
Lerma AL 14 869 43730
Bosio AL 15 1227 44957
Sant'Olcese GE 15 5906 50863
Arenzano GE 15 11519 62382
Belforte Monferrato AL 16 515 62897
Urbe SV 16 700 63597
Carrosio AL 16 510 64107
Genova GE 17 586655 650762
Tagliolo Monferrato AL 17 1581 652343
Ronco Scrivia GE 17 4417 656760
Savignone GE 17 3205 659965
Casella GE 17 3144 663109
Montaldeo AL 17 265 663374
Parodi Ligure AL 17 715 664089
Ovada AL 17 11477 675566
Cogoleto GE 18 9172 684738
Molare AL 19 2181 686919
Gavi AL 19 4614 691533
Isola del Cantone GE 20 1540 693073
San Cristoforo AL 20 608 693681
Castelletto d'Orba AL 20 2047 695728

Municipalities with at least 50000 inhabitants

An earthquake occurred to
17 Km NW of Genova (586655 inhabitants)
34 Km NE of Savona (61345 inhabitants)
46 Km SE of Alessandria (93943 inhabitants)
63 Km SE of Asti (76202 inhabitants)
80 Km SW of Pavia (72576 inhabitants)
89 Km S of Vigevano (63310 inhabitants)
93 Km SW of Piacenza (102191 inhabitants)
95 Km W of La Spezia (93959 inhabitants)
99 Km E of Cuneo (56081 inhabitants)
Recent and historical seismicity

These maps show the seismic activity in different time intervals, before the seismic event to which they refer. Data reported in the first two maps come from the analysis carried out in real time by the personnel of the INGV Operating Rooms, immediately after each earthquake. The third map shows data from 1985 to the date of the earthquake: the locations are reviewed by the seismological analysts of the INGV Italian Seismic Bulletin (Bollettino Sismico Italiano dell’INGV). The localization parameters (hypocentral coordinates and magnitude) are the best possible estimate with the data available to the INGV, but are constantly updated according to further data that become available. The location and magnitude parameters, subsequently reviewed by seismological analysts, may vary.

Earthquakes of the 3 days preceding this event

Earthquakes of the 3 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 0.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 72 hours preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes of the 90 days preceding this event

Earthquakes of the 90 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 2.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 90 days preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes from 1985 to the date of the event

Earthquakes from 1985 to the date of the event

This map shows the earthquake epicenters with magnitude ≥ 3.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, from 1985 to the date of this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes since 1000 AD until 2019

Earthquakes since 1000 AD until 2019

This map shows the epicenters of the historical earthquakes catalogue CPT15 (Catalogo Parametrico dei Terremoti Italiani, 2015 version 3.0, https://doi.org/10.13127/cpti/cpti15.3) since 1000 AD until 2019. The size of the square indicates the different classes of magnitude. For earthquakes with magnitude ≥ 6.0, it is also shown the year of occurrence and the magnitude value. The black and white star is the epicenter of the current earthquake.
Seismic hazard

Seismic hazard maps provide probabilistic estimates of the earthquake ground shaking exceeding a given threshold in a given geographic region within a given time window. Thus, it is not a deterministic prediction - a target that may be never reached given the complexity of the earthquake physical phenomenon - nor of the maximum expected earthquake since this has extremely low probabilities to occur.

In 2004, it was published the seismic hazard map of Italy (http://zonesismiche.mi.ingv.it) that provides a picture of the most hazardous geographic regions. The seismic hazard map of Italy (GdL MPS, 2004; rif. Ordinanza PCM del 28 aprile 2006, n. 3519, All. 1b) provides the 10% probability of exceedance in 50 years of the horizontal acceleration at rock sites (i.e., Vs30>800 m/s; cat. A, 3.2.1 of the D.M. 14.09.2005).

The colours indicate the various values of the ground acceleration that have 10% to be exceeded within 50 years. In general, the colours associated to low values of acceleration refer to areas that are less hazardous and stronger earthquakes repeat less frequently although they may still occur.

Seismic hazard map

Seismic hazard map

This map shows the seismic hazard map of Italy for the region where the earthquake occurred.
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 1986-04-25
19:57:41
44.518 8.788 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 26019
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1986-04-25 19:57:41 ± 0.365
Latitude 44.5180 ± 0.0287
Longitude 8.7880 ± 0.0118
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 26019

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) 3329.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 237
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) 0.00130
Epicentral distance of station farthest from the epicenter (degree) 0.00615
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:2.0

Field Value
Value 2.0
Uncertainty
Num. used stations 1
Type of magnitude Md
Reference to an origin 26019
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 17:27:43
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
--.ROB.Z. 1986-04-25T19:58:05.10 10.0 undecidable manual SG 252 0.0062 -0.45 0.2
--.FIN.Z. 1986-04-25T19:58:00.40 10.0 undecidable manual SG 233 0.0046 0.34 0.5
--.ROB.Z. 1986-04-25T19:57:55.20 10.0 undecidable manual PG 252 0.0062 -0.21 1.4
--.CKI.Z. 1986-04-25T19:57:55.00 10.0 undecidable manual SG 255 0.0033 -0.55 0.2
--.FIN.Z. 1986-04-25T19:57:52.50 10.0 undecidable manual PG 233 0.0046 0.26 1.5
--.CKI.Z. 1986-04-25T19:57:50.00 10.0 undecidable manual PG 255 0.0033 0.36 1.1
--.GEN.Z. 1986-04-25T19:57:48.00 10.0 undecidable manual SG 132 0.0013 -0.16 0.8
--.GEN.Z. 1986-04-25T19:57:45.30 10.0 undecidable manual PG 132 0.0013 -0.07 2.3
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Fault Plane solutions

Fault Plane solutions

The map reports the fault plane solutions for earthquakes in the region from 1977 to the date of this event. Red moment tensors are determined using the Regional Centroid Moment Tensor technique (RCMT, http://www.bo.ingv.it/RCMT) applied for earthquakes with magnitude larger than 4.5 in the Euro-Mediterranenan area. Occasionally, when a station azimuthal coverage exists RCMTs can be obtained also for earthquakes with magnitude down to 4.0. The gray moment tensors are obtained with the Time Domain Moment Tensor method (TDMT, http://terremoti.ingv.it/tdmt). This technique is applied to earthquakes with magnitude ML greater than 3.2, when it is possible. The size of symbols scales with the calculated moment magnitude Mw.
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download