TerraSond Performs Hydrographic and Geophysical Surveys in South AmericaFeb 17, 2010 - TerraSond Limited
TerraSond Limited was contracted to perform a single beam hydrographic survey, side scan sonar survey, and a magnetometer geophysical survey in the Gulf of Arauco near the coastal cities of Lota and Arauco, Chile. TerraSond responded quickly and was on-site conducting the survey work within three weeks of the client’s initial request. The intent of the survey was to provide a hazard survey to map the bathymetry at 150 meter line spacing and to verify possible obstructions with side scan sonar data in anticipation of a seismic survey. Magnetometer data was also acquired for use in mapping features associated with the local geology. The magnetometer data would be used subsequently in the analysis of the seismic data. Data acquisition was continuous from February 17th – 27th, when a major 8.8 magnitude earthquake occurred near the survey area. Survey operations ceased and crew members were evacuated to safe ground. Data acquisition resumed on March 4th and continued until the project was completed on March 14th. Because bathymetry data was acquired immediately prior to and after the earthquake, this data was unique in being able to show the considerable uplift, >1m, in the survey area. Echo sounder data was also recorded as the tsunami waves passed the survey vessel. Data was obtained utilizing an Odom CVM Echo Sounder (200 kHz), C-NAV 2050G Real-Time GIPSY Differential Navigation System, Odom Digibar Pro Sound Velocimeter, EdgeTech 4200 Side Scan Sonar, and a Klein 3900 Side Scan Sonar systems. Data was processed using HYPACK navigation, acquisition, and processing software, CARIS HIPS processing software and SonarWiz software from Chesapeake Technology.