Continuous seiche in bays and harbors

The article of record as published may be found at http://dx.doi.org/10.5194/osd-12-2361-2015Discussion PaperSeiches are often considered a transitory phenomenon wherein large amplitude water level oscillations are excited by a geophysical event, eventually dissipating some time after the event. However, continuous small-amplitude seiches have recently been recognized presenting a question as to the origin of continuous forcing. We examine 6 bays around the Pacific where continuous seiches are evident, and based on spectral, modal and kinematic analysis suggest that tidally-forced shelf-resonances are a primary driver of continuous seiches

Field Performance of Reinforced Dunes for Improving Coastal Resilience

Increased coastal erosion rates have forced communities to rethink how to manage vulnerable coastlines. In many locations there is a trend towards implementing temporary engineering solutions, such as geotextile sand containers (GSCs) and geo-tubes, to stabilize erosion hot spots and assess the impact of these designs while long-term solutions are developed. GSCs and geo-tubes have the potential to increase the resilience of natural systems to protect coastlines from smaller storm events (e.g. 25-year storms) while providing flexibility in design considering the uncertainty regarding future rates of sea level rise and storm frequency. The objective of this paper is to summarize the performance of geotextile stabilized coastal sites and present results of on-going field studies to assess the performance of GSC reinforced dunes in Montauk, NY. The better-than-expected, resilient performance of GSCs and geo-tubes at most locations and recent reinforcement of dunes, bluffs, and shorelines in New York, Massachusetts, and Hawaii emphasizes the need for continued field research and in situ monitoring to collect high-quality performance data to better evaluate laboratory experiments and numerical models developed to predict the hydraulic stability of these systems