The Health and Safety Executive have commissioned KW Ltd to carry out a fundamental assessment of the dynamic characteristics of jack-up structures. The overall objective of the study is to develop an understanding of the possible failure modes of such structures and to prepare a basis for the fundamental modelling of the dynamic interaction of the structure, loading and foundations of jack-up ...

Sound backscattered to a sonar from a seabed decreases in intensity with increasing range (R) due to geometrical spreading. As a far-range approximation, a geometrical spreading correction of +30 log R decibels may be applied. A correction based on an accurate estimation of the area of the seabed ensonified by the sonar pulse incorporates additional terms that are a function of: range, sonic ra...

Introduction: Our lack of understanding of the evolution of seabed roughness (e.g., sand ripples) in sandy coastal regions inhibits our ability to accurately forecast waves and currents and ultimately large-scale morphodynamics. Most wave and circulation models input a constant bottom roughness value (i.e., friction factor) or fixed bed profile that parameterizes the effects of seabed roughness...

We describe two new species amongst the most common sponges living on the seabed (inter-reef) of the Great Barrier Reef (GBR) collected during a multi-agency survey (GBR Seabed Biodiversity Project 2003–2006) of the shelf benthic biota using a trawl and dredge at 1254 sites. More than 1,200 sponge morphospecies (operational taxonomic units or OTUs) were recognised, many of which are potentially...

The MAPEX2000 experiments were conducted in the Mediterranean Sea in March, 2000 to determine seabed properties using a towed acoustic source and receiver array. Towed systems are advantageous because they are easy to deploy from a ship and the moving platform offers the possibility for estimating spatially variable (range-dependent) seabed properties. In this paper, seabed parameters are deter...

Solid Marine Wastes present on the seabed and floating on the sea surface were investigated in the Aegean Sea. Compared to other locations in the Mediterranean, litter concentration on Northern to Mid Aegean Seabed is moderate even in populated gulfs, whereas floating marine debris concentrations are low and dominated by recreational items, probably restricted to summer season.

In this paper, a two-dimensional numerical model for wave-seabed-pipeline interaction is developed to examine the wave-induced uplift force onto pipelines buried in sloping seabeds. The Reynolds-averaged Navier stokes equation and poro-elastic are used simulate wave motion seabed response, respectively. Meanwhile, pipeline considered be elastic. Firstly, three laboratory experiments taken verif...

The approach includes both theoretical and measurement components. One measurement approach exploits the very high geoacoustic information content in direct path measurements of seabed reflection and scattering. Another measurement approach, based on long-range reverberation, has much less information content but is nonetheless a powerful way to explore scales inherent in the seabed. Both kinds...

The ocean floor is home to a wealth of species, some of which—such as this bamboo coral (Isidella tentaculum)—have only recently been discovered. Proponents of seabed mining claim it causes less ecological damage than terrestrial extraction. But some researchers are concerned that seabed mining could overwhelm deep-sea ecosystems, adding to concerns about the health of the oceans.

Submarine pipelines failures lead to oil spills in water and may even lead to explosions with heavy financial and environmental damages. Trawl gear is one of the main factors in the failure of the submarine pipelines. In this paper, sensitivity analysis is performed on influence of height and span length alternations on the response of pipeline against the traction caused by trawling pull-over ...