Earthquake with magnitude of Md 2.8 on date 06-10-1991 and time 23:28:26 (UTC) in region 4 km E Santo Stefano di Magra (SP)
A magnitude Md 2.8 earthquake occured in region: 4 km E Santo Stefano di Magra (SP), on
- 06-10-1991 23:28:26 (UTC)
- 07-10-1991 00:28:26 (UTC +01:00) Italian time
and geographic coordinates (lat, lon) 44.1590, 9.9700 at 7 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.
Display location by
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Municipalities within 20 km from the epicenter
Distances are determinated based on the geographic coordintes of the (Istat).
| Municipality | Region | Distance (km) | Inhabitants | Cumulative Inhabitants |
|---|---|---|---|---|
| Santo Stefano di Magra | SP | 4 | 9360 | 9360 |
| Fosdinovo | MS | 5 | 4883 | 14243 |
| Sarzana | SP | 5 | 21976 | 36219 |
| Aulla | MS | 6 | 11263 | 47482 |
| Podenzana | MS | 6 | 2180 | 49662 |
| Bolano | SP | 7 | 7813 | 57475 |
| Arcola | SP | 7 | 10607 | 68082 |
| Vezzano Ligure | SP | 7 | 7356 | 75438 |
| Castelnuovo Magra | SP | 8 | 8415 | 83853 |
| Follo | SP | 9 | 6337 | 90190 |
| Tresana | MS | 9 | 2044 | 92234 |
| Ortonovo | SP | 10 | 8277 | 100511 |
| Lerici | SP | 10 | 10228 | 110739 |
| Ameglia | SP | 10 | 4365 | 115104 |
| La Spezia | SP | 13 | 93959 | 209063 |
| Licciana Nardi | MS | 13 | 4949 | 214012 |
| Carrara | MS | 14 | 63133 | 277145 |
| Calice al Cornoviglio | SP | 14 | 1138 | 278283 |
| Villafranca in Lunigiana | MS | 15 | 4770 | 283053 |
| Fivizzano | MS | 15 | 7925 | 290978 |
| Portovenere | SP | 16 | 3630 | 294608 |
| Riccò del Golfo di Spezia | SP | 16 | 3698 | 298306 |
| Beverino | SP | 16 | 2429 | 300735 |
| Casola in Lunigiana | MS | 17 | 988 | 301723 |
| Bagnone | MS | 18 | 1887 | 303610 |
| Mulazzo | MS | 19 | 2424 | 306034 |
| Minucciano | LU | 19 | 2102 | 308136 |
| Massa | MS | 19 | 69479 | 377615 |
| Filattiera | MS | 19 | 2309 | 379924 |
| Riomaggiore | SP | 20 | 1576 | 381500 |
| Pignone | SP | 20 | 565 | 382065 |
| Rocchetta di Vara | SP | 20 | 703 | 382768 |
Municipalities with at least 50000 inhabitants
An earthquake occurred to
13 Km E of La Spezia (93959 inhabitants)
14 Km NW of Carrara (63133 inhabitants)
19 Km NW of Massa (69479 inhabitants)
39 Km NW of Viareggio (62467 inhabitants)
55 Km NW of Lucca (89046 inhabitants)
60 Km NW of Pisa (89158 inhabitants)
73 Km NW of Livorno (159219 inhabitants)
77 Km SW of Parma (192836 inhabitants)
80 Km SW of Reggio nell'Emilia (171345 inhabitants)
80 Km W of Pistoia (90315 inhabitants)
87 Km E of Genova (586655 inhabitants)
93 Km SW of Modena (184973 inhabitants)
95 Km W of Prato (191150 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
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
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
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
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
This map shows the seismic hazard map of Italy for the region where the earthquake occurred.
Shakemap
Not available maps for this sismic event.
Felt maps
Not available maps for this sismic event.
Locations history
| Type | Magnitude | Date and Time (UTC) | Latitude | Longitude | Depth (km) | Published time (UTC) | Author | Location ID |
|---|---|---|---|---|---|---|---|---|
|
Bulletin Rev1000 |
Md 2.8 | 1991-10-06 23:28:26 |
44.159 | 9.97 | 7 | 2013-07-15 08:40:51 |
Bollettino Sismico Italiano INGV | 150649 |
Preferred location and magnitude until now.
Origin information
Origin
| Field | Value |
|---|---|
| Time (UTC) | 1991-10-06 23:28:26 ± 0.48 |
| Latitude | 44.1590 ± 0.0149 |
| Longitude | 9.9700 ± 0.0130 |
| Depth (km) | 7 ± 3 (from location) |
| Evaluation mode of Origin | manual |
| Evaluation status of Origin | reviewed |
| Version | 1000 -> BULLETIN-VAX |
| Event type | earthquake |
| Origin ID | 150649 |
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) | 1954.5 |
| Confidence level of the uncertainty (%) | 68 |
Quality
| Field | Value |
|---|---|
| Largest azimuthal gap in station distribution as seen from epicenter (degree) | 85 |
| Number of associated phases, regardless of their use for origin computation | 55 |
| Number of defining phases | 55 |
| RMS of the travel time residuals of the arrivals used for the origin computation (sec) | 0.7 |
| Epicentral distance of station closest to the epicenter (degree) | 0.00413 |
| Epicentral distance of station farthest from the epicenter (degree) | 0.04986 |
| Number of stations at which the event was observed | 33 |
| Number of stations from which data was used for origin computation | 33 |
Magnitude information
Md:2.8
| Field | Value |
|---|---|
| Value | 2.8 |
| Uncertainty | |
| Num. used stations | 6 |
| Type of magnitude | Md |
| Reference to an origin | 150649 |
| Agency | INGV |
| Autore | Bollettino Sismico Italiano INGV |
| Time of creation (UTC) | 2013-01-04 19:20:36 |
Picking and Arrival
| SCNL | Time | Uncertainty | Polarity | Evaluation_mode | Phase | Azimuth | Distance(km) | Takeoff_angle | Residual | Weight |
|---|---|---|---|---|---|---|---|---|---|---|
| --.LOR.Z. | 1991-10-06T23:30:44.60 | 10.0 | undecidable | manual | SN | 308 | 5.2614 | 1.02 | 0.3 | |
| --.LBF.Z. | 1991-10-06T23:30:38.60 | 10.0 | undecidable | manual | SN | 306 | 5.0505 | 0.3 | 0.5 | |
| --.SMF.Z. | 1991-10-06T23:30:37.00 | 10.0 | undecidable | manual | SN | 302 | 4.9617 | 0.79 | 0.4 | |
| --.CDF.Z. | 1991-10-06T23:30:28.40 | 10.0 | undecidable | manual | SN | 337 | 4.6398 | -0.07 | 0.6 | |
| --.HAU.Z. | 1991-10-06T23:30:28.40 | 10.0 | undecidable | manual | SN | 328 | 4.5843 | 1.09 | 0.3 | |
| --.BSF.Z. | 1991-10-06T23:30:20.00 | 10.0 | undecidable | manual | SN | 330 | 4.2735 | 0.03 | 0.6 | |
| --.BGF.Z. | 1991-10-06T23:29:50.40 | 10.0 | undecidable | manual | PN | 298 | 5.5389 | 0.92 | 0.7 | |
| --.AVF.Z. | 1991-10-06T23:29:47.60 | 10.0 | undecidable | manual | PN | 302 | 5.3169 | 1.08 | 0.6 | |
| --.LOR.Z. | 1991-10-06T23:29:46.80 | 10.0 | undecidable | manual | PN | 308 | 5.2614 | 1.02 | 0.7 | |
| --.LBF.Z. | 1991-10-06T23:29:44.00 | 10.0 | undecidable | manual | PN | 306 | 5.0505 | 1.27 | 0.5 | |
| --.LRG.Z. | 1991-10-06T23:29:42.20 | 10.0 | undecidable | manual | SN | 256 | 2.6862 | -0.04 | 0.8 | |
| --.SMF.Z. | 1991-10-06T23:29:42.00 | 10.0 | undecidable | manual | PN | 302 | 4.9617 | 0.48 | 1.2 | |
| --.LMR.Z. | 1991-10-06T23:29:39.80 | 10.0 | undecidable | manual | SN | 253 | 2.6196 | -0.88 | 0.5 | |
| --.HAU.Z. | 1991-10-06T23:29:37.30 | 10.0 | undecidable | manual | PN | 328 | 4.5843 | 0.91 | 0.9 | |
| --.CDF.Z. | 1991-10-06T23:29:37.20 | 10.0 | undecidable | manual | PN | 337 | 4.6398 | 0.16 | 1.4 | |
| --.FRF.Z. | 1991-10-06T23:29:36.80 | 10.0 | undecidable | manual | SN | 257 | 2.4642 | -0.02 | 0.8 | |
| --.BSF.Z. | 1991-10-06T23:29:33.20 | 10.0 | undecidable | manual | PN | 330 | 4.2735 | 1.06 | 0.8 | |
| --.CTI.Z. | 1991-10-06T23:29:30.57 | 10.0 | undecidable | manual | SN | 31 | 2.22 | -0.55 | 0.6 | |
| --.SBF.Z. | 1991-10-06T23:29:21.60 | 10.0 | undecidable | manual | SN | 262 | 1.8426 | -0.41 | 0.7 | |
| --.PGF.Z. | 1991-10-06T23:29:20.80 | 10.0 | undecidable | manual | SN | 204 | 1.7538 | 0.88 | 0.5 | |
| --.FVI.Z. | 1991-10-06T23:29:16.00 | 10.0 | undecidable | manual | PN | 38 | 3.1302 | -0.34 | 1.6 | |
| --.CRE.Z. | 1991-10-06T23:29:14.00 | 10.0 | undecidable | manual | SN | 110 | 1.5207 | -0.38 | 0.7 | |
| --.SAL.Z. | 1991-10-06T23:29:13.97 | 10.0 | undecidable | manual | SN | 15 | 1.4874 | 0.16 | 0.8 | |
| --.IMI.Z. | 1991-10-06T23:29:11.89 | 10.0 | undecidable | manual | SN! | 261 | 1.5096 | -2.2 | 0 | |
| --.LRG.Z. | 1991-10-06T23:29:11.00 | 10.0 | undecidable | manual | PN | 256 | 2.6862 | 0.64 | 1.5 | |
| --.ROB.Z. | 1991-10-06T23:29:11.19 | 10.0 | undecidable | manual | SN! | 276 | 1.4985 | -2.8 | 0 | |
| --.LMR.Z. | 1991-10-06T23:29:09.40 | 10.0 | undecidable | manual | PN | 253 | 2.6196 | -0.06 | 2 | |
| --.FRF.Z. | 1991-10-06T23:29:07.50 | 10.0 | undecidable | manual | PN | 257 | 2.4642 | 0.27 | 1.9 | |
| --.FIN.Z. | 1991-10-06T23:29:06.15 | 10.0 | undecidable | manual | SN | 273 | 1.2543 | -2.02 | 0.1 | |
| --.LSD.Z. | 1991-10-06T23:29:06.97 | 10.0 | undecidable | manual | PN | 304 | 2.3754 | 0.95 | 1.2 | |
| --.ASS.Z. | 1991-10-06T23:29:05.92 | 10.0 | undecidable | manual | PN | 118 | 2.22 | 1.99 | 0.2 | |
| --.CKI.Z. | 1991-10-06T23:29:04.66 | 10.0 | undecidable | manual | SN! | 283 | 1.2321 | -2.9 | 0 | |
| --.CTI.Z. | 1991-10-06T23:29:03.70 | 10.0 | undecidable | manual | PN | 31 | 2.22 | -0.87 | 1.2 | |
| --.PZZ.Z. | 1991-10-06T23:29:01.84 | 10.0 | undecidable | manual | PN | 281 | 2.0757 | -0.05 | 2 | |
| --.BHB.Z. | 1991-10-06T23:29:01.20 | 10.0 | undecidable | manual | PN | 290 | 2.0424 | -0.2 | 2 | |
| --.PCP.Z. | 1991-10-06T23:29:00.71 | 10.0 | undecidable | manual | SN! | 291 | 1.0767 | -3.28 | 0 | |
| --.ORX.Z. | 1991-10-06T23:29:00.00 | 10.0 | undecidable | manual | PN | 317 | 2.0313 | -1.31 | 0.7 | |
| --.SBF.Z. | 1991-10-06T23:28:59.00 | 10.0 | undecidable | manual | PN | 262 | 1.8426 | 0.32 | 1.9 | |
| --.STV.Z. | 1991-10-06T23:28:58.66 | 10.0 | undecidable | manual | PN | 274 | 1.887 | -0.68 | 1.5 | |
| --.PTF.Z. | 1991-10-06T23:28:58.40 | 10.0 | undecidable | manual | SG! | 104 | 0.8103 | 2.95 | 0 | |
| --.PGF.Z. | 1991-10-06T23:28:58.20 | 10.0 | undecidable | manual | PN | 204 | 1.7538 | 0.73 | 1.5 | |
| --.ENR.Z. | 1991-10-06T23:28:57.83 | 10.0 | undecidable | manual | PN | 273 | 1.8204 | -0.61 | 1.6 | |
| --.CRE.Z. | 1991-10-06T23:28:54.35 | 10.0 | undecidable | manual | PN | 110 | 1.5207 | 0.08 | 2 | |
| --.ROB.Z. | 1991-10-06T23:28:53.13 | 10.0 | undecidable | manual | PN | 276 | 1.4985 | -0.91 | 1.2 | |
| --.IMI.Z. | 1991-10-06T23:28:53.43 | 10.0 | undecidable | manual | PN | 261 | 1.5096 | -0.68 | 1.5 | |
| --.SAL.Z. | 1991-10-06T23:28:53.66 | 10.0 | undecidable | manual | PN | 15 | 1.4874 | -0.28 | 1.9 | |
| --.CKI.Z. | 1991-10-06T23:28:49.30 | 10.0 | undecidable | manual | PN | 283 | 1.2321 | -1.3 | 0.7 | |
| --.FIN.Z. | 1991-10-06T23:28:49.10 | 10.0 | undecidable | manual | PN | 273 | 1.2543 | -1.58 | 0.4 | |
| --.SEI.Z. | 1991-10-06T23:28:46.90 | 10.0 | undecidable | manual | PG | 95 | 0.999 | 0.09 | 2 | |
| --.PCP.Z. | 1991-10-06T23:28:46.70 | 10.0 | undecidable | manual | PN | 291 | 1.0767 | -1.57 | 0.4 | |
| --.MME.Z. | 1991-10-06T23:28:45.50 | 10.0 | undecidable | manual | SG | 86 | 0.5217 | -0.63 | 0.5 | |
| --.PTF.Z. | 1991-10-06T23:28:44.80 | 10.0 | undecidable | manual | PG | 104 | 0.8103 | 1.45 | 0.6 | |
| --.BDI.Z. | 1991-10-06T23:28:44.50 | 10.0 | undecidable | manual | SG | 102 | 0.4551 | -0.02 | 0.8 | |
| --.MME.Z. | 1991-10-06T23:28:37.00 | 10.0 | undecidable | manual | PG | 86 | 0.5217 | -0.96 | 1 | |
| --.BDI.Z. | 1991-10-06T23:28:36.00 | 10.0 | undecidable | manual | PG | 102 | 0.4551 | -0.77 | 1.3 |
TDMT - Time Domain Moment Tensor
Not available TDMT solution for this seismic event.
Fault Plane solutions in the area
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.