GHASS

Type Oceanographic cruise
Ship Pourquoi pas ?
Ship owner Ifremer
Dates 31/08/2015 - 30/09/2015
Chief scientist(s) KER Stéphan, RIBOULOT Vincent

GM-GEOSCIENCES MARINES

IFREMER Centre de Bretagne

ZI Pointe du diable

CS 10070

29280 PLOUZANE

+33(0)2 98.22.42.24

geosciences.marines@ifremer.fr

http://wwz.ifremer.fr/gm

DOI 10.17600/15000500
Objective The GHASS cruise's objective was to study the possible link between the presence of free gas, gas hydrates and underwater landslides and sedimentary deformations. To this end, a detection and imaging phase was first conducted based on water column acoustics and seismic tools (HR and SYSIF). On specific sites revealed by this first phase, a second phase was undertaken to sample sediments by coring and collect in-situ measurements. Geotechnical (Penfeld and piezometer) and geochemical (CTD and on cores) measurements and sedimentology analyses were performed in this way. The scientific objectives of the second phase were to study the source and composition of free gas and gas hydrates, the dynamic nature of hydrate/gas systems and the mechanical properties of surface sediments. Data integration should make it possible to quantify the concentration in hydrates and free gas and establish whether there is a proven link between their presence and the gravity instabilities and deformations observed during the cruise. The related project is called Aléas géologiques REM/GM.

Data managed by SISMER

Sampling operations

Bibliography

Publications

Ballas Gregory, Garziglia Sebastien, Sultan Nabil, Pelleter Ewan, Toucanne Samuel, Marsset Tania, Riboulot Vincent, Ker Stephan (2018). Influence of early diagenesis on geotechnical properties of clay sediments (Romania, Black Sea). Engineering Geology, 240, 175-188. http://doi.org/10.1016/j.enggeo.2018.04.019

Hillman Jess I. T., Klaucke Ingo, Bialas Joerg, Feldman Howard, Drexler Tina, Awwiller David, Atgin Orhan, Cifci Gunay, Badhani Shray (2018). Gas migration pathways and slope failures in the Danube Fan, Black Sea. Marine And Petroleum Geology, 92, 1069-1084. http://doi.org/10.1016/j.marpetgeo.2018.03.025

Marsset Bruno, Ker Stephan, Thomas Yannick, Colin Florent (2018). Deep-towed high resolution seismic imaging II: Determination of P-wave velocity distribution. Deep-sea Research Part I-oceanographic Research Papers, 132, 29-36. http://doi.org/10.1016/j.dsr.2017.12.005

Riboulot Vincent, Ker Stephan, Sultan Nabil, Thomas Yannick, Marsset Bruno, Scalabrin Carla, Ruffine Livio, Boulart Cedric, Ion Gabriel (2018). Freshwater lake to salt-water sea causing widespread hydrate dissociation in the Black Sea. Nature Communications, 9(117), 1-8. Publisher's official version : http://doi.org/10.1038/s41467-017-02271-z , Open Access version : http://archimer.ifremer.fr/doc/00418/52981/

Riboulot Vincent, Cattaneo Antonio, Scalabrin Carla, Gaillot Arnaud, Jouet Gwenael, Ballas Gregory, Marsset Tania, Garziglia Sebastien, Ker Stephan (2017). La géomorphologie des fonds marins et la présence d’hydrates de gaz contrôlent les émissions de gaz dans la Mer Noire au large de la Roumanie / Control of the geomorphology and gas hydrate extent on widespread gas emissions offshore Romania. Bulletin De La Societe Geologique De France, 188(4), 26 (1-12). Publisher's official version : http://doi.org/10.1051/bsgf/2017182 , Open Access version : http://archimer.ifremer.fr/doc/00407/51860/