Fiscal Year	2015
Division	Research & Sponsored Programs
Department	Naval Research Program
Investigator(s)	Reeder, Davis B.
Sponsor	NPS Naval Research Program (Navy)
Summary	Very large subaqueous sand dunes were discovered on the upper continental slope of the northern South China Sea (SCS) in the spring of 2007 on the upper continental slope in water depths of 160 m to 600 m. While subaqueous dunes are found in many locations throughout the world’s oceans and coastal zones, these particular dunes appear to be unique for two principal reasons: their location on the upper continental slope and their distinctive formation mechanism (approximately 30 episodic, extremely energetic, large amplitude trans-basin non-linear internal wave events (NLIW’s) each lunar cycle). These sand dunes are important acoustical features, as it is expected that they will cause operationally significant anomalies in the acoustical field, which will impact the performance of both active and passive sonar systems. Knowledge of the impact of these dunes will inform ASW asset placement and performance assessment. This work consists of analysis of data collected during the 2013 and 2014 field experiments and associated modeling to fully understand the acoustic propagation characteristics and operational impacts of the sand dunes.
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Publications	Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data	Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal