Except in the deep ocean, the seabed has a major influence on low-frequency acoustic propagation. The formulation of an adequate geoacoustic model of the seabed is therefore one of the most important tasks facing anyone carrying out acoustic propagation modelling to predict underwater sound levels in coastal and continental shelf waters. It is often assumed that seabed layering on scales signif...

A new, closed-form hysteretic model of the capillary pressure-saturation and relative permeability-saturation relationship has been implemented into ITOUGH2. The hysteretic capillary pressure function is based on the van Genuchten model, with a modified version of the dependent domain model of Mualem to describe the scanning curves. Hysteresis in the relative permeability relations is considere...

In this study, the hydrodynamic forces acting on the seabed around the pipeline in unidirectional ocean currents have been investigated numerically. Two types of seabed are considered, i.e., plane and distorted seabed. The influences of gap between pipeline and seabed on the distribution of forces along the seabed are studied in detail. Computational results show that the pressure at the upstre...

Following the approach of [22], we derive a system of FokkerPlanck equations to model a stock-market in which hysteretic agents can take long and short positions. We show numerically that the resulting mesoscopic model has rich behaviour, being hysteretic at the mesoscale and allowing bubbles and volatility clustering in particular.

Propagation and reverberation of acoustic fields in shallow waters depend strongly on the spatial variability of seabed geoacoustic parameters, and lack of knowledge of seabed variability is often a limiting factor in acoustic modeling applications. However, direct sampling (e.g., coring) of vertical and lateral variability is expensive and laborious, and matched-field and other long-range inve...

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...

Propagation and reverberation of acoustic fields in shallow waters depend strongly on the spatial variability of seabed geoacoustic parameters, and lack of knowledge of seabed variability is often a limiting factor in acoustic modeling applications. However, direct sampling (e.g., coring) of vertical and lateral variability is expensive and laborious, and matched-field and other long-range inve...

This paper deals with the determination of the conditions for which the hysteretic Bouc-Wen model is consistent with the physical phenomenon it is supposed to represent. In particular, we derive the conditions on the model parameters under which the model is stable, asymptotically dissipative and verifies the hysteretic property. These conditions are in the form of algebraic inequalities to be ...

Nature conservation and fisheries management often focus on particular seabed features that are considered vulnerable or important to commercial species. As a result, individual seabed types are protected in isolation, without any understanding of what effect the mixture of seabed types within the landscape has on ecosystem functions. Here we undertook predictive seabed modelling within a coast...