Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.8 on date 31-08-1988 and time 11:59:20 (Italy) in region 3 km SE Novi Ligure (AL)

A magnitude Md 2.8 earthquake occured in region: 3 km SE Novi Ligure (AL), on

  • 31-08-1988 09:59:20 (UTC)
  • 31-08-1988 11:59:20 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.7400, 8.8020 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.

Hai sentito il terremoto? Clicca qui

Did you feel it? Fill in the questionnaire.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Novi Ligure AL 3 28154 28154
Tassarolo AL 3 672 28826
Pasturana AL 4 1318 30144
Serravalle Scrivia AL 5 6128 36272
Stazzano AL 5 2486 38758
Francavilla Bisio AL 6 531 39289
Gavi AL 6 4614 43903
Cassano Spinola AL 6 1731 45634
Pozzolo Formigaro AL 6 4775 50409
San Cristoforo AL 7 608 51017
Gavazzana AL 8 180 51197
Vignole Borbera AL 8 2182 53379
Basaluzzo AL 8 2087 55466
Parodi Ligure AL 8 715 56181
Sardigliano AL 9 406 56587
Arquata Scrivia AL 9 6409 62996
Capriata d'Orba AL 9 1904 64900
Carrosio AL 9 510 65410
Castelletto d'Orba AL 10 2047 67457
Villalvernia AL 10 955 68412
Montaldeo AL 10 265 68677
Bosio AL 10 1227 69904
Fresonara AL 10 731 70635
Sant'Agata Fossili AL 11 425 71060
Carezzano AL 11 431 71491
Predosa AL 11 2048 73539
Borghetto di Borbera AL 11 1966 75505
Paderna AL 12 220 75725
Mornese AL 12 737 76462
Silvano d'Orba AL 12 1988 78450
Castellania AL 12 90 78540
Spineto Scrivia AL 12 337 78877
Casaleggio Boiro AL 13 372 79249
Costa Vescovato AL 13 335 79584
Carbonara Scrivia AL 14 1122 80706
Lerma AL 14 869 81575
Bosco Marengo AL 14 2457 84032
Voltaggio AL 14 738 84770
Grondona AL 14 510 85280
Villaromagnano AL 14 715 85995
Rocca Grimalda AL 14 1512 87507
Frugarolo AL 15 1968 89475
Avolasca AL 15 294 89769
Tagliolo Monferrato AL 15 1581 91350
Cerreto Grue AL 15 323 91673
Isola del Cantone GE 16 1540 93213
Montegioco AL 16 313 93526
Garbagna AL 16 696 94222
Ovada AL 17 11477 105699
Carpeneto AL 17 977 106676
Belforte Monferrato AL 17 515 107191
Sarezzano AL 17 1171 108362
Fraconalto AL 17 336 108698
Casal Cermelli AL 18 1234 109932
Montaldo Bormida AL 18 664 110596
Tortona AL 18 27437 138033
Sezzadio AL 19 1246 139279
Castelspina AL 19 416 139695
Casasco AL 19 129 139824
Trisobbio AL 19 655 140479
Ronco Scrivia GE 19 4417 144896
Roccaforte Ligure AL 19 136 145032
Berzano di Tortona AL 19 157 145189
Cantalupo Ligure AL 19 527 145716
Montemarzino AL 19 341 146057
Orsara Bormida AL 20 424 146481
Dernice AL 20 185 146666

Municipalities with at least 50000 inhabitants

An earthquake occurred to
24 Km SE of Alessandria (93943 inhabitants)
38 Km N of Genova (586655 inhabitants)
50 Km E of Asti (76202 inhabitants)
54 Km NE of Savona (61345 inhabitants)
57 Km SW of Pavia (72576 inhabitants)
65 Km S of Vigevano (63310 inhabitants)
78 Km W of Piacenza (102191 inhabitants)
80 Km S of Novara (104380 inhabitants)
87 Km SW of Milano (1345851 inhabitants)
90 Km S of Rho (50434 inhabitants)
93 Km E of Moncalieri (57294 inhabitants)
95 Km SW of Sesto San Giovanni (81608 inhabitants)
96 Km S of Legnano (60262 inhabitants)
96 Km E of Torino (890529 inhabitants)
97 Km SW of Cinisello Balsamo (75078 inhabitants)
98 Km S of Busto Arsizio (83106 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 2.8
ML-VAX 2.0 		1988-08-31
09:59:20		 44.74 8.802 7 2013-07-15
08:40:51		 Bollettino Sismico Italiano INGV 76519
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1988-08-31 09:59:20 ± 0.323
Latitude 44.7400 ± 0.0110
Longitude 8.8020 ± 0.0133
Depth (km) 7 ± 2 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 76519

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) 1613.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 76
Number of associated phases, regardless of their use for origin computation 35
Number of defining phases 35
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.6
Epicentral distance of station closest to the epicenter (degree) 0.00300
Epicentral distance of station farthest from the epicenter (degree) 0.01951
Number of stations at which the event was observed 22
Number of stations from which data was used for origin computation 22
Magnitudes information

Md:2.8

Field Value
Value 2.8
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 76519
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 18:12:06

ML:2.0

Field Value
Value 2.0
Uncertainty
Num. used stations 4
Type of magnitude ML
Reference to an origin 76519
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 13:07:13
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.LRG.Z. 1988-08-31T10:00:24.20 10.0 undecidable manual SN 234 2.1645 0.33 0.5
--.BDI.Z. 1988-08-31T10:00:07.50 10.0 undecidable manual SN 117 1.443 0.82 0.4
--.SBF.Z. 1988-08-31T10:00:04.20 10.0 undecidable manual SN 228 1.2987 0.77 0.5
--.LRG.Z. 1988-08-31T10:00:00.40 10.0 undecidable manual PN! 234 2.1645 3.19 0
--.PZZ.Z. 1988-08-31T10:00:00.30 10.0 undecidable manual SN 259 1.221 -1.21 0.2
--.STV.Z. 1988-08-31T09:59:59.80 10.0 undecidable manual SN 245 1.1544 0.07 0.8
--.VAI.Z. 1988-08-31T09:59:58.68 10.0 undecidable manual SN 358 1.1211 -0.31 0.7
--.ORO.Z. 1988-08-31T09:59:56.84 10.0 undecidable manual SG 327 1.0545 -0.5 0.6
--.LPL.Z. 1988-08-31T09:59:51.20 10.0 undecidable manual PN 298 1.6428 1.13 0.7
--.LPG.Z. 1988-08-31T09:59:51.10 10.0 undecidable manual PN 298 1.6317 1.31 0.5
--.BDI.Z. 1988-08-31T09:59:48.00 10.0 undecidable manual PN 117 1.443 0.71 1.2
--.MME.Z. 1988-08-31T09:59:48.94 10.0 undecidable manual PN 111 1.4541 1.52 0.3
--.ROB.Z. 1988-08-31T09:59:48.00 10.0 undecidable manual SG 236 0.7881 -0.83 0.4
--.SBF.Z. 1988-08-31T09:59:47.10 10.0 undecidable manual PN 228 1.2987 1.7 0.2
--.RRL.Z. 1988-08-31T09:59:47.30 10.0 undecidable manual PN 277 1.443 0.13 1.7
--.BVT.Z. 1988-08-31T09:59:46.30 10.0 undecidable manual SG 109 0.7659 -1.75 0.1
--.LSD.Z. 1988-08-31T09:59:45.50 10.0 undecidable manual PN 302 1.3542 -0.62 1.2
--.STV.Z. 1988-08-31T09:59:44.00 10.0 undecidable manual PN 245 1.1544 0.73 1.4
--.FIN.Z. 1988-08-31T09:59:44.50 10.0 undecidable manual SG 218 0.6771 -0.67 0.5
--.PZZ.Z. 1988-08-31T09:59:43.70 10.0 undecidable manual PN 259 1.221 -0.6 1.3
--.VAI.Z. 1988-08-31T09:59:43.39 10.0 undecidable manual PN 358 1.1211 0.55 1.7
--.DOI.Z. 1988-08-31T09:59:42.89 10.0 undecidable manual PN 258 1.1211 -0.04 2
--.RSP.Z. 1988-08-31T09:59:42.40 10.0 undecidable manual PN 291 1.1544 -1.01 0.7
--.VEA.Z. 1988-08-31T09:59:42.80 10.0 undecidable manual SG 75 0.5883 0.23 0.8
--.ORX.Z. 1988-08-31T09:59:42.20 10.0 undecidable manual PG 327 1.0656 0.23 2
--.IMI.Z. 1988-08-31T09:59:41.10 10.0 undecidable manual PG 218 1.0545 -0.7 1.2
--.ORO.Z. 1988-08-31T09:59:41.97 10.0 undecidable manual PG 327 1.0545 0.07 2
--.BOB.Z. 1988-08-31T09:59:37.66 10.0 undecidable manual SG 86 0.4551 -0.45 0.7
--.ROB.Z. 1988-08-31T09:59:36.90 10.0 undecidable manual PG 236 0.7881 -0.08 2
--.BVT.Z. 1988-08-31T09:59:35.60 10.0 undecidable manual PG 109 0.7659 -0.93 0.9
--.GEN.Z. 1988-08-31T09:59:34.20 10.0 undecidable manual SG 163 0.333 0.3 0.8
--.FIN.Z. 1988-08-31T09:59:34.60 10.0 undecidable manual PG 218 0.6771 -0.26 1.8
--.VEA.Z. 1988-08-31T09:59:33.00 10.0 undecidable manual PG 75 0.5883 -0.37 1.8
--.BOB.Z. 1988-08-31T09:59:30.29 10.0 undecidable manual PG 86 0.4551 -0.5 1.6
--.GEN.Z. 1988-08-31T09:59:28.70 10.0 undecidable manual PG 163 0.333 0.34 1.9
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, /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