Overpressure within upper continental slope sediments from CPTU data, Gulf of Lion, NW Mediterranean Sea

Lafuerza, Sara; Sultan, Nabil; Canals, Miquel; Frigola, Jaime; Berné, Serge; Jouet, Gwénaël; Galavazi, M.; Sierro, Francisco J.

doi:10.1007/s00531-008-0376-2

Cited by 23 publications

(21 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both methods lead to consistent results with the presence of high excess pore pressure in the superficial (< 10 m) sediments. These results confirm what was already observed by Lafuerza et al () who calculated an excess pore pressure profile from in situ piezocone measurements. Lafuerza et al () suggested that the origin of this superficial excess pore pressure and the presence of pockmark fields in the area (Fig.…”

Section: Resultssupporting

confidence: 92%

“…These results confirm what was already observed by Lafuerza et al () who calculated an excess pore pressure profile from in situ piezocone measurements. Lafuerza et al () suggested that the origin of this superficial excess pore pressure and the presence of pockmark fields in the area (Fig. ) is a combination of the accumulation of free gas in deep permeable sediment layers and the gas exsolution processes related to sea level variations.…”

Section: Resultssupporting

confidence: 92%

“…The Ifremer piezometer was used during the PRISME cruise. It is a free‐fall device with a sediment‐piercing lance attached to a recoverable instrument part (Sultan et al ). It is ballasted with lead weights to penetrate a range of sediment types in water depths of up to 6000 m. The length of the lance used depends upon the stiffness of the sediment, up to a maximum length of 12 m. Pore pressures are measured relative to hydrostatic pressure at different ports on the 60 mm diameter lance using specially adapted differential pressure sensors connected to the pressure ports and the surrounding seawater.…”

Section: Geophysical Datamentioning

confidence: 99%

See 2 more Smart Citations

A multi‐disciplinary approach to marine shallow geohazard assessment

Marsset

Thomas

Sultan

et al. 2012

Near Surface Geophysics

Self Cite

View full text Add to dashboard Cite

Seismic velocities together with sediment/rock compaction models are of common use in the oil industry to predict reservoir pressures and to detect and identify any potential hazard associated with over‐pressured formations. Excess pore pressure is a key parameter for geohazard assessment, nevertheless this approach is very seldom applied to shallow offshore engineering as it requires expensive ground‐truth boreholes. The simultaneous availability in the Bourcart‐Hérault canyon interfluve (Gulf of Lion – NW Mediterranean) of 1) geotechnical and sedimentological data (300 m boreholes) from the PROMESS project; 2) in situ pore pressure measurements; and 3) High Resolution (HR) seismic geophysical data showing the presence of active structures in relation to fluid circulation, allows the importance of a multi‐disciplinary approach to shallow geohazard assessment to be illustrated through a case study. The velocity field obtained from HR seismic data is interpreted in light of the neighbouring boreholes and resulting velocity anomalies are translated in terms of fluid overpressure and free gas content. Additional in situ surface geotechnical measurements (piezometers) are then taken into account and the role of these parameters is discussed.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Resultssupporting

confidence: 92%

Section: Geophysical Datamentioning

confidence: 99%

See 1 more Smart Citation

A multi‐disciplinary approach to marine shallow geohazard assessment

Marsset

Thomas

Sultan

et al. 2012

Near Surface Geophysics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Indeed, Lafuerza et al . [] and Riboulot et al . [] have proposed that relative sea level falls decrease hydrostatic pressure and thus increase gas volume in the fluid reservoir, with the formation of gas bubbles subsequently inducing pockmark formation.…”

Section: Introductionmentioning

confidence: 99%

Control of Quaternary sea‐level changes on gas seeps

Riboulot

Thomas

Berné

et al. 2014

Geophysical Research Letters

View full text Add to dashboard Cite

Gas seeping to the seafloor through structures such as pockmarks may contribute significantly to the enrichment of atmospheric greenhouse gases and global warming. Gas seeps in the Gulf of Lions, Western Mediterranean, are cyclical, and pockmark "life" is governed both by sediment accumulation on the continental margin and Quaternary climate changes. Three-dimensional seismic data, correlated to multi-proxy analysis of a deep borehole, have shown that these pockmarks are associated with oblique chimneys. The prograding chimney geometry demonstrates the syn-sedimentary and long-lasting functioning of the gas seeps. Gas chimneys have reworked chronologically constrained stratigraphic units and have functioned episodically, with maximum activity around sea level lowstands. Therefore, we argue that one of the main driving mechanisms responsible for their formation is the variation in hydrostatic pressure driven by relative sea level changes.

show abstract

“…An additional factor might be the lowering of the storm-wave base (and related storm-triggered mass wasting), and possibly the exsolution of free gas contained in organic-rich clinoforms of the shelf-edge deltas. This latter process has been demonstrated to be an important factor in the formation of pockmarks situated along the Bourcart/Herault interfluve (Lafuerza et al, 2009;Riboulot et al, 2014).…”

Section: Accepted Manuscriptmentioning

confidence: 94%

Sea-level control on the connection between shelf-edge deltas and the Bourcart canyon head (western Mediterranean) during the last glacial/interglacial cycle

et al. 2015

Self Cite

View full text Add to dashboard Cite

A dense grid of high-and very high resolution seismic data, together with piston cores and borehole data providing time constraints, enables us to reconstruct the history of the Bourcart canyon head in the western Mediterranean Sea during the last glacial/interglacial cycle. The canyon fill is composed of confined channel-levee systems fed by a series of successively active shelf fluvial systems, originating from the west and north. Most of the preserved infill corresponds to the interval between Marine Isotope Stage (MIS) 3 and the early deglacial (19 cal ka BP). Its deposition was strongly controlled by a relative sea level that impacted the direct fluvial/canyon connection. During a period of around 100 kyr between MIS 6 and MIS 2, the canyon "prograded" by about 3 km. More precisely, several parasequences can be identified within the canyon fill. They correspond to forced-regressed parasequences (linked to punctuated sea-level falls) topped by a progradational-aggradational parasequence (linked to a hypothetical 19-ka meltwater pulse (MWP)). The bounding surfaces between forced-regressed parasequences are condensed intervals formed during intervals of relative sediment starvation due to flooding episodes. The meandering pattern of the axial incision visible within the canyon head, which can be traced landward up to the Agly paleo-river, is interpreted as the result of hyperpycnal flows initiated in the river mouth in a context of increased rainfall and mountain glacier flushing during the early deglacial.Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. Graphical abstract :Highlights ► First detailed chronology of canyon head infill, which took place between 38 and 19 ka BP during the last glacial cycle, ► Fluvial connection (in relation with sea-level changes) is the key controlling parameter. ► The seismic stratigraphic motif consists in confined channel-levee systems with chaotic infill, topped by fluvial facies. ► Large MTDs are related to Bond cycles.

show abstract

Overpressure within upper continental slope sediments from CPTU data, Gulf of Lion, NW Mediterranean Sea

Cited by 23 publications

References 35 publications

A multi‐disciplinary approach to marine shallow geohazard assessment

A multi‐disciplinary approach to marine shallow geohazard assessment

Control of Quaternary sea‐level changes on gas seeps

Sea-level control on the connection between shelf-edge deltas and the Bourcart canyon head (western Mediterranean) during the last glacial/interglacial cycle

Contact Info

Product

Resources

About