Tonga, Fanga'uta Lagoon, 2003, High Resolution Bathymetry Survey Chart

This record holds the bathymetry chart within the island of Tongatapu, Fanga'uta Lagoon. The chart is the result of the multibeam bathymetry survey that was undertaken by the Applied Geoscience and Technology Division (SOPAC) of SPC over a period of 5 weeks from 13 of November to the 7th of December 2003 in Tongatapu and within Fanga’uta Lagoon. The surveyed area extends from the coast to approximately 10 km offshore. Water depths within the surveyed area ranged from 10 to 1500 m offshore and between 0 to 7 m within the lagoon. Minimum water depths were measured near the coast on the outer slope of the fringing reef with depths becoming deeper in a general seaward direction at a mean slope angle of 25o towards the offshore limits of the survey area. Bathymetry survey was carried out using a Reson 8160 deep water MBES and a Echotrac Single beam echosounder. The magnetometer was deployed throughout the duration of the survey and the extent of seabed data indicates the area where magnetometer was collected. The resultant data was used to produce a bathymetry chart of Fanga'uta at 1:75 000 and dataset in XYZ text file, available from a separate record.This work was initiated by the SOPAC/EU Reducing Vulnerability of Pacific ACP States Project (Task no.: NR 1.1.1). Bathymetry chart can be downloaded from this record under the Distribution Info section with appropriate permission from the Secretariat.This bathymetric map gives a descriptive picture of the ocean bottom terrain, vividly revealing the size, shape and distribution of underwater features, and serve as the basic tool for scientific, engineering, marine geophysical and environmental studies, as well as marine and coastal resource management.Multibeam Bathymetry data by SOPAC/EU:Date of Survey November/December 2003; Acquisition system - Reson 8160 Multibeam EchosounderCollection software - Hypack 4.3 Processing software, Hypack 4.3A Data presentation - Surfer 8.03Survey vessel - M/V TuragalevuObserved soundings have not been reduced to vertical datum Geodetic datum WGS84 Ellipsoid WGS84 Projection UTM Zone 1 South Horizontal positioning Stand alone GPS.