A Lagrangian flow model is used to investigate highly nonlinear, dispersive waves generated by moving seabed deformation (MSD) of an otherwise horizontal seabed. Applications include free surface wave responses co-seismic displacements and novel bed-driven making systems in surfing competitions. This paper considers gravity viscous liquid, without restrictions on steepness, dispersion coefficie...

− We can obtain the performance of the marine seismometer upon the sediment to know its coupling in the bottom sea. This paper deals with the coupling parameters in order to obtain the geophone response through the frequency. The use of the shake table and vibration calibrator allows to deduce the coupling transfer function between the geophone and the sediment sea without using a detailed mode...

strict new safety rules announced after the Deepwater Horizon disaster, but in most cases won't be subjected to new environmental reviews. The announcement means that some drilling could resume within weeks, although the exact timing remains unclear. But the policy doesn't affect the more than a dozen permit requests that were pending when the moratorium took effect or have been filed since. Th...

The coupled interaction of long standing hydrodynamic waves with a deformable non-Newtonian seabed is examined using a two-layer model for which the upper layer fluid is inviscid and the lower layer is bi-viscous. The two-dimensional response of the system to forcing by a predominantly longitudinal (cross-shore) standing wave perturbed by a small transverse (along-shore) component is determined...

Computational modeling is a valuable complementary tool to assess behavior of bottom trawl fishing gears. A simplified model of the gear that mainly affects to the net is proposed. The model is constrained to steady towing conditions, flat seabed and gear symmetry. Simulations proportionate a number of relevant outcomes like distribution of tensions at the warp, balance of forces at the otterbo...

This proposal is a direct response to Challenge 22: Target detection in clutter. The Oceans Systems laboratory have a large experience in Target Detection and Classification in high resolution sonar imagery using a variety of techniques based on target responses and highlight shadow pairs[1,2,3]. Experiments on real scenarios show that these techniques work well in benign environments (flat and...

Reported measurements of seabed scattering are largely confined to relatively low frequencies, up to 300 kHz, see, e.g., [Jackson and Richardson] and references therein. Still higher frequencies, up to a few megahertz, are used in seafloor imagery (e.g., in pencil-beam sonars), particularly to observe dynamic processes at the seafloor in shallow water. From the physics of sound-sediment interac...

This research stream is focussed on offshore hazards, with particular attention to the mobility of the seabed – whether through large scale geological events, or local scale sediment transport processes. This report is divided into two broad areas. We have extensive activity to report on the subject of seabed mobility, through studies around the O-Tube program (see also the separate report on t...

The laboratory miniature vane shear test (MVST) has been widely used to measure the undrained strength of marine sediments in offshore engineering. However, transfer soil sample tube samplers from seabed releases situ confining stress acting on and will decrease strength. In this research, order investigate effects sediments, Coupled Eulerian-Lagrangian (CEL) approach ABAQUS is model three-dime...

A model suited for control tasks is developed for a submerged offshore pipe during the pipelay operation. The pipe is fixed in the touchdown point at the seabed in one end and attached to a pipelay vessel in the other end. The developed model is discrete and is on the form of the robot equation with minimal coordinates. Thus the methods of controller synthesis and stability analysis can be appl...