Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 2.4 on date 18-03-1991 and time 01:07:03 (UTC) in region Costa Toscana settentrionale (Massa Carrara, Lucca, Pisa)

A magnitude Md 2.4 earthquake occured in region: Costa Toscana settentrionale (Massa Carrara, Lucca, Pisa), on

  • 18-03-1991 01:07:03 (UTC)
  • 18-03-1991 02:07:03 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 43.9890, 9.9660 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.

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Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Ameglia SP 9 4365 4365
Lerici SP 11 10228 14593
Ortonovo SP 12 8277 22870
Portovenere SP 13 3630 26500
Castelnuovo Magra SP 13 8415 34915
Sarzana SP 14 21976 56891
Carrara MS 15 63133 120024
Arcola SP 15 10607 130631
Massa MS 15 69479 200110
Forte dei Marmi LU 16 7510 207620
Fosdinovo MS 17 4883 212503
Montignoso MS 17 10323 222826
La Spezia SP 17 93959 316785
Vezzano Ligure SP 18 7356 324141
Santo Stefano di Magra SP 20 9360 333501

Municipalities with at least 50000 inhabitants

An earthquake occurred to
15 Km SW of Carrara (63133 inhabitants)
15 Km W of Massa (69479 inhabitants)
17 Km SE of La Spezia (93959 inhabitants)
27 Km NW of Viareggio (62467 inhabitants)
46 Km W of Lucca (89046 inhabitants)
46 Km NW of Pisa (89158 inhabitants)
56 Km NW of Livorno (159219 inhabitants)
77 Km W of Pistoia (90315 inhabitants)
91 Km W of Prato (191150 inhabitants)
95 Km E of Genova (586655 inhabitants)
95 Km SW of Parma (192836 inhabitants)
95 Km SW of Reggio nell'Emilia (171345 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 2.4
M 2.4 		1991-03-18
01:07:03		 43.989 9.966 10 2013-07-15
08:41:04		 Bollettino Sismico Italiano INGV 137689
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-03-18 01:07:03 ± 0.25
Latitude 43.9890 ± 0.0294
Longitude 9.9660 ± 0.0256
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 137689

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) 3857.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 102
Number of associated phases, regardless of their use for origin computation 21
Number of defining phases 21
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) 0.02477
Number of stations at which the event was observed 13
Number of stations from which data was used for origin computation 13
Magnitudes information

Md:2.4

Field Value
Value 2.4
Uncertainty
Num. used stations 2
Type of magnitude Md
Reference to an origin 137689
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:08:26

M:2.4

Field Value
Value 2.4
Uncertainty
Num. used stations
Type of magnitude M
Reference to an origin 137689
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 09:42:56
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.LRG.Z. 1991-03-18T01:08:15.20 10.0 undecidable manual SN! 260 2.6529 -2.28 0
--.LMR.Z. 1991-03-18T01:08:14.00 10.0 undecidable manual SN 256 2.5752 -1.71 0.1
--.FRF.Z. 1991-03-18T01:08:11.00 10.0 undecidable manual SN 261 2.4309 -1.13 0.3
--.SBF.Z. 1991-03-18T01:07:56.40 10.0 undecidable manual SN 267 1.8204 -1.29 0.3
--.PGF.Z. 1991-03-18T01:07:52.40 10.0 undecidable manual SN 206 1.5984 0 0.8
--.LPL.Z. 1991-03-18T01:07:48.00 10.0 undecidable manual PN 305 2.7528 0.32 1.3
--.LRG.Z. 1991-03-18T01:07:46.40 10.0 undecidable manual PN 260 2.6529 0.06 1.5
--.CKI.Z. 1991-03-18T01:07:46.00 10.0 undecidable manual SN 290 1.2765 1.22 0.3
--.LMR.Z. 1991-03-18T01:07:44.90 10.0 undecidable manual PN 256 2.5752 -0.41 1.3
--.FRF.Z. 1991-03-18T01:07:43.00 10.0 undecidable manual PN 261 2.4309 -0.25 1.5
--.SBF.Z. 1991-03-18T01:07:34.50 10.0 undecidable manual PN 267 1.8204 -0.41 1.6
--.PGF.Z. 1991-03-18T01:07:32.80 10.0 undecidable manual PN 206 1.5984 0.94 1.1
--.CRE.Z. 1991-03-18T01:07:31.77 10.0 undecidable manual PN 104 1.4763 1.63 0.4
--.SFI.Z. 1991-03-18T01:07:29.15 10.0 undecidable manual PN 93 1.3431 0.68 1.5
--.CKI.Z. 1991-03-18T01:07:28.00 10.0 undecidable manual PN 290 1.2765 0.54 1.6
--.PGD.Z. 1991-03-18T01:07:27.47 10.0 undecidable manual PN 94 1.2654 0.21 1.9
--.BOB.Z. 1991-03-18T01:07:21.66 10.0 undecidable manual PG 335 0.8547 0.81 1.3
--.MME.Z. 1991-03-18T01:07:21.70 10.0 undecidable manual SG! 69 0.555 -2.78 0
--.BDI.Z. 1991-03-18T01:07:17.66 10.0 undecidable manual SG! 81 0.4551 -2.79 0
--.MME.Z. 1991-03-18T01:07:14.16 10.0 undecidable manual PG 69 0.555 -1.21 0.8
--.BDI.Z. 1991-03-18T01:07:11.68 10.0 undecidable manual PG 81 0.4551 -1.73 0.3
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