The GROSMARIN
(which stands for GrandROSMARIN) cruise is proposed by UMR Géosciences Azur (with fellow
french and italian research groups). Its goals are to better characterize active structures along this zone and to assess the resulting seismic hazard in a sort of continuation with respect to the MALISAR
experiment, which has already surveyed some active structures through shallow observations.
The GROSMARIN cruise is in fact the necessary counterpart to characterize them at depth

Anglade, A.

Bellier, O.

Beslier, M. O.

Bethoux, N.

Brunel, D.

Courboulex, F.

Deschamps, A.

Desprez, O.

Dessa, J. X.

Eva, C.

Eva, E.

Ferretti, G.

Flueh, E.

Hello, Y.

Klingelhoefer, F.

Lefeldt, M.

Manchuel, K.

Pavan, M.

Ruiz Fernandez, M.

Scafidi, D.

Solarino, S.

Spallarossa, D.

Verdier, E.

Zunino, E.

Earth-prints Repository

in progress and the interpretation of the anomalies found should be tested. In-land results suggest
the occurrence of 5 tsunami events within the past 4100 yr yielding an average recurrence for tsuna-
mi inundations of about 1000 yr. For the off-shore results more events are found in the same peri-
od of time. Even though we do not know if the anomalies in the MS-06 core are representative of
tsunamis only or alternatively of local earthquakes, the results suggest that the marine environment
is more preservative with respect to the littoral one with the advantage of a sedimentary record gen-
erally more continuous and potentially more sensible to anomalous events like earthquakes and
tsunamis. 
Acknowledgements. Research funded within the agreement INGV-DPC 2004-2006, project S2 “Valutazione
del potenziale sismogenetico e probabilità dei forti terremoti in Italia”, RU 2.2a (M.S. Barbano) and 2.2b (P.M.
De Martini) and by EU project TRANSFER CT n. 037058 (Coord. S. TInti - U. of Bologna).
References
Coltelli M., Del Carlo P. & Vezzoli L. (1998) - The discovery of a Plinian basaltic eruption of Roman age at Mt. Etna. Geology, 26,
1095-1098.
CPTI Working group 2004 - Catalogo Parametrico dei Terremoti Italiani, version 2004 (CPTI04). INGV, Bologna.
http://emidius.mi.ingv.it/CPTI/.
Smedile A., De Martini P.M., Barbano M.S., Gerardi F., Pantosti D., Pirrotta C., Cosentino M., Del Carlo P. & Guarnieri P. (2007)
- Identification of paleotsunami deposits in the Augusta Bay area (eastern Sicily, Italy): paleoseismological implication. XXVI
Convegno GNGTS, Extended Abstract Volume, 207-211.
Smedile A., P.M. De Martini, L. Bellucci, L. Gasperini, L. Sagnotti, P. Del Carlo, A. Polonia, D. Pantosti, M.S. Barbano, F. Gerardi
(2008). Paleotsunami deposits in the Augusta Bay area (Eastern Sicily, Italy): preliminary results from offshore data, Rend.
online Soc. Geol. It., 2, 1-3.
THE GROSMARIN EXPERIMENT
S. Solarino1, J.X. Dessa2, N. Béthoux2, M.O. Beslier2, Y. Hello2, A. Anglade2, O. Desprez2, 
M. Ruiz Fernandez2, K. Manchuel2, E. Verdier2, A. Deschamps3, F. Courboulex3, D. Brunel3, 
F. Klingelhoefer4, O. Bellier5, M. Lefeldt6, E. Flueh6, E. Eva1, C. Eva7, M. Pavan7, E. Zunino7, 
D. Scafidi7, D. Spallarossa7, G. Ferretti7
1 Istituto Nazionale di Geofisica e Vulcanologia, CNT, Roma, Italy
2 UMR Geosciences Azur, Villefranche sur Mer, France
3 UMR Geosciences Azur, CNRS, Sophia Antipolis, France
4 Ifremer DRO/GM, Plouzané, France
5 CEREGE, Aix-en-Provence, France
6 IFM-GEOMAR, Kiel, Germany
7 DipTeRis, Università di Genova, Italy
The Ligurian margin is a passive margin, seismically active and subjected to gravitative move-
ments. The data provided from different disciplines indicate that the active deformation in this sec-
tor is among the strongest ever experienced in Western Italy and Southern France.
The current geodynamics of the basin is not completely understood yet, and somewhat under
interest and debate of the scientific community. The latest results on the recent evolution of the
Alps-Mediterranean system, which acknowledge a halting of the collision at the level of Alps and
a transfer of the active collision to the Algerian margin (Jolivet and Facenna, 2000; Nocquet and
Calais, 2004; Wortel and Spakman, 2000) suggest that the area under study experience extension,
but studies made at a local level (Bethoux et al., 1992; Eva and Solarino, 1998) would instead show
that the area is under compression and hypothesize a closure of the Ligurian basin. The complex
origin is not the unique element that renders this sector of peculiar importance. In fact, the interest
for the area is reinforced by its seismic activity that, although of low to moderate energy, acts in a
sector of high vulnerability. Some historical events involved dramatic social and material damages,
like the 1831 and 1854, M=5.5 and M=5.7 respectively, earthquakes or the 1887, M=6.3 event (600
185
GNGTS 2008 SESSIONE 2.1
casualties) that also caused tsunami waves observed along the 250 km of the Ligurian coast from
Genoa to Cannes, with run-up heights around 1-2 metres (Eva and Rabinovich, 1997). The recent
growth of population (that now accounts for more than 2.500.000 inhabitants between Cannes and
Genoa), the setting of numerous industries and the tourist business of the area are additional moti-
vation for monitoring the area from the seismic point of view and especially to make specific stud-
ies on the seismogenic structures of this sector. Events with magnitude greater than 4.5 to 5.0 are in
fact recorded every 5 years (Courboulex et al., 2007), but apart from these strong events, the area
undergoes a rather weak microseismicity that often remains undetected and always poorly located
by land seismic networks.
Finally, the natural risks associated to this sector are boosted by the presence of steep canyons
that incise the offshore margin and favour gravitative slopes. The sediment masses accumulate on
top of these canyons and may slip even after an earthquake of moderate magnitude. Within this
frame, the identification, the location and the detailed description of both the seismogenic and the
gravitative structures, on land and at sea, assume a paramount importance. The GROSMARIN
(which stands for GrandROSMARIN) cruise is proposed by UMR Géosciences Azur (with fellow
french and italian research groups). Its goals are to better characterize active structures along this
zone and to assess the resulting seismic hazard in a sort of continuation with respect to the MAL-
ISAR experiment, which has already surveyed some active structures through shallow observations.
The GROSMARIN cruise is in fact the necessary counterpart to characterize them at depth. The
activity within the project is organized into two steps. 
The first part of the experiment, conducted at sea with the R/V’s l’Atalante, has consisted in an
active survey to (1) study the
microseismicity along a part
of the northern margin of the
Ligurian Basin, offshore
France and Italy, roughly
extended from Villefranche
to Imperia and (2) to realise
a 3D tomography by wide-
angle seismics. In the eight
days between 19 and 27
April 2008 shots every 60
seconds have been made on
profiles parallel (about 150
km length) and perpendicu-
lar (about 100 km offshore)
to the coast.
The second part of the
experiment is instead based
on the recording of natural
seismicity and is more tuned
to the seismotectonic
aspects. In fact, among its
goals are the definition and
characterization of the rela-
tionships between structures
on land and at sea, to get a
3D tomographic model
updated with respect to the
186
GNGTS 2008 SESSIONE 2.1
Fig. 1 - Main features of the GROSMARIN project. The circles show the
location of the 21 OBS stations. The squares indicate the temporary or
permanent seismic stations operating on French and Italian land. The lines
show the shooting profiles.
 
already existing one (Eva et al., 2001) by local earthquake inversion (Thurber, 1983) to be com-
pared with that obtained by wide-angle seismics and to infer more details (location, geometry,
extension) on the seismogenic structures of the Ligurian Sea. In order to get the best data coverage,
in the experiment a network of temporary seismic stations has been set. Offshore, 21 OBS’s (Ocean
Bottom Seismometers) have been deployed, 15 out of which operate for a 5-month period above the
active part of the margin. A dense temporary seismic network complements the observation zone on
land. In fact, 16 temporary stations have been deployed (see Fig. 1 for details) for the recording of
the active data; a part of these instruments will operate until all OBS are removed. 
Nowadays the comprehensive database of active data, which will contain the about 500000 seis-
mic recordings, is under compilation and processing. The preliminary analysis of the seismic wave-
forms show an excellent signal to noise ratio, in particular for the night shots, due to the careful
choice of number and types of guns to be used. It is noteworthy to underline that, in optimal condi-
tions, shots have been recorded even by seismic stations not included in the experiment and locat-
ed much further north of the study area, like those operating in the northern sector of the Piedmont
region (Fig. 2).
187
GNGTS 2008 SESSIONE 2.1
Fig. 2 - Example of waveforms recorded
within the active part of the GROSMARIN
project. The map on the bottom panel shows
the position of the stations. Even the far
stations (PZZ, PCP) exhibit a rather good
signal to noise ratio.
Acknowledgements. This project is strongly linked with those led by the teams of Geosciences Azur and focu-
sed on the study of the seismic hazard along the Riviera area (PASSERELLE programme, « Risque-Décision-
Territoire » of the ministry of environment ; IRIS project, « ACI risques naturels » programme, CURARE pro-
gramme) and with those led by INGV (Istituto Nazionale di Geofisica e Vulcanologia) within the DPC
(Dipartimento della Protezione Civile) 2007-09 frame under the task S1 (Determination of the seismic poten-
tial for the computation of the seismic hazard in Italy). The project is also included in the site characterization
that should lead to the installation of a multi-parameter sea bottom observatories (ESONET/NoE).
References
Bethoux N. , Fréchet J. , Guyoton F., Thouvenot F. , Cattaneo M. , Eva C. , Nicolas M., Granet M.; 1992: A closing Ligurian
Sea? Pure and Applied Geophysics., 139, 2, 179-194.
Courboulex F., Larroque C., Deschamps A., Kohrs-Sansorny C., Gelis C., Got J.L., Charreau J., Stephan J.F., Bethoux N., Virieux
J., Brunel D., Maron C., Duval A.M., Perez L., Mondielli P.; 2007: Seismic hazard on the French Riviera: observations,
interpretations and simulations. Geophys. Journ. Int. 170, 1, 387-400
Eva C., Rabinovich A.B.; 1997: The February 23, 1887 tsunami recorded on the Ligurian coast, Western Mediterranean. Geophys.
Res. Lett., 24, 2211-2214
Eva E. and Solarino S.; 1998: Variations of stress directions in the western Alpine arc. Geophys. Journ. Int., 135, 2, 438-449.
Eva E., Solarino S., Spallarossa D.; 2001: Seismicity and crustal structure beneath the western Ligurian derived from local
earthquake tomography. Tectonophysics., 339, 495-510
Jolivet, L., Facenna C.; 2000: Mediterranean extension and the Africa-Eurasia collision. Tectonics, 19, 6, 1095-1107.
Nocquet J.M., Calais E.; 2004: Geodetic measurements of crustal deformation in the Western Mediterranean and Europe. Pure and
Applied Geophysics, 161, 661-681.
Thurber C.;1983: Earthquake locations and three dimensional crustal velocity structure in the Coyote lake area, central California.
J.Geophys. Res., 88, 8226-8236.
Wortel M.R.J., Spakman W.; 2000: Subduction and slab detachment in the Mediterranean-Carpathian region. Science, 290, 1910-
1917.
LE VERSIONI 2008 DEL DATABASE MACROSISMICO ITALIANO (DBMI08) 
E DEL CATALOGO PARAMETRICO DEI TERREMOTI ITALIANI (CPTI08) 
Gruppo di Lavoro CPTI
c/o Istituto Nazionale di Geofisica e Vulcanologia, sezione di Milano-Pavia, Milano
A partire dalla pubblicazione delle versioni 2004 di CPTI e DBMI, nell’ambito delle attività isti-
tuzionali INGV e con il contributo dei progetti INGV-DPC 2004-2006 è stata continuata la raccol-
ta critica dei nuovi studi macrosismici prodotti negli uutlimi anni. Per dare collocazione stabile a
tale raccolta è stata avviata la compilazione di un inventario denominato ISMI (Inventario degli
Studi Storico Macrosismici Italiani), che comprende ad oggi circa 10000 studi relativi a più di 3500
terremoti avvenuti tra l’anno 1000 e il 2006. L’inventario è organizzato in famiglie di studi relativi
allo stesso evento, fra i quali viene scelto di volta in volta lo studio ritenuto più rappresentativo, da
utilizzarsi per la compilazione di DBMI e CPTI. I dati macrosismici selezionati per DBMI08 pro-
vengono in parte da studi che hanno già contribuito a DBMI04 (Stucchi et al., 2007), relativi a ter-
remoti per i quali non sono emersi dati aggiornati. In parte provengono invece da nuovi studi, fra i
quali:
• studi storici e rilievi macrosismici di autori INGV
• CFTI4med
• studi pubblicati da altri autori 
• selezione di dati del bollettino macrosismico INGV
• catalogo macrosismico dei terremoti etnei.
DBMI08 contiene in totale circa 85000 dati di intensità relativi a più di 1500 terremoti. Circa
24000 dati sono riferiti a 500 eventi non inclusi in DBMI04. Più di 34000 dati sono invece relativi
a eventi già compresi in DBMI04 di intensità e derivano da studi aggiornati rispetto a quelli utiliz-
zati in DBMI04. Come d’uso i dati confluiti in DBMI08 sono stati sottoposti a un processo di omo-
geneizzazione e di validazione, per quanto riguarda principalmente la georeferenziazione delle
188
GNGTS 2008 SESSIONE 2.1


The Grosmarin experiment

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The Grosmarin experiment

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