Sea Technology

MAY 2013

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New Sea Level Rise Models Predict Early Pacifc Inundation Dynamic modeling of sea level rise, which takes storm wind and wave action into account, indicates future problems for some low-lying Pacifc islands under climate-change scenarios, compared to the passive computer modeling used in earlier research, according to a new U.S. Geological Survey (USGS) report. The report compared passive "bathtub" inundation models with dynamic models for two of the Northwestern Hawaiian Islands in the Papahanaumokuakea Marine National Monument. Midway Atoll, with islands on the shallow (2 to 8 meters deep) atoll rim and a deep, central lagoon, and Laysan, which is higher, with a 20 to 30 meter deep rim and an island in the center of the atoll, were studied. The two locations exhibit landforms and coastal features common to many Pacifc islands. Managed by the U.S. Fish and Wildlife Service, they are also among the world's most important nesting and breeding sites for migratory birds and other wildlife. Passive "bathtub" inundation models typically used to forecast sea-level rise impacts suggest that most of the low-lying atolls in the Pacifc Islands will still be above sea level for the next 50 to 150 years. But when taking wave-driven processes into account, the new forecast predicts that many of the atolls will be inundated, contaminating freshwater supplies and thus making the islands uninhabitable much sooner than had been expected. At least twice as much land is forecast to be inundated on Midway and Laysan by sea level rise than was projected by passive models. These fndings have importance not only for island wildlife, but for the tens of thousands of people who live on other low-lying Pacifc Island groups such as those in the Republic of the Marshall Islands and the Federated States of Micronesia. The new models offer tools for forecasting where agricultural land may be damaged by repeated saltwater overwash, as well as where groundwater may be contaminated by saltwater. Copepods Swim With Power Strokes to Escape Predators To escape from the jaws and claws of predators in cold, viscous water, ma- QINSy The modular design, user friendly user interface, comprehensive help and support of international standards and exchange formats, mean QINSy is equally well suited to less complex bathymetric surveys as it is to highly complex multi-vessel and multi-sensor offshore construction projects. rine copepods switch from a wave-like swimming stroke to big power strokes, a behavior that has been revealed via 3D high-speed digital holography, according to a study in the Proceedings of the National Academy of Sciences. The technique uses a microscope with a laser and a high-speed digital camera to catch the rapid movements of the microscopic animals in a 3D volume of liquid. Copepods are key components of marine food webs. Understanding how they might respond to changes in the environment is important for assessing the health of oceans now and in the future. Water viscosity naturally increases as the temperature drops. The researchers discovered that the power stroke is triggered only by colder temperature, not viscosity alone because the muscles that control the copepods' appendages are affected by temperature. If viscosity increases without temperature change—e.g., during an algal bloom or pollution event—the copepods' escape ability declines. This affects their populations as coastal algal blooms and pollution increase. n Fledermaus Hydrographic Laser scanning Coastal mapping Environmental Rig moves Exploration Dredging Geological Pipe laying Rock dumping Offshore Habitat mapping Hydrographic Academic Sidescan Sonar Offshore ROV inspection Fledermaus is the industry leading interactive 4D geospatial processing and analysis tool. The intuitive user interface allows users to rapidly gain insight and extract more information from their data, that in turn promotes data processing efficiency, quality control accuracy, and data analysis completeness. Marine construction Marine Data Management Marine Data Management QINSy Qastor Fledermaus The company with the solutions for your hydrogeomatics data and maritime projects www.sea-technology.com www.qps.nl For details contact: sales@qps.nl MAY 2013 / st 73

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