LOS ANGELES, Dec 13 (Reuters) - A NASA-led international satellite mission was set for blastoff from Southern California early on Thursday on a major Earth science project to conduct a comprehensive survey of the world's oceans, lakes and rivers for the first time.Developed by the U.S. space agency in collaboration with its counterparts in France and Canada, SWOT was one of 15 missions listed by the National Research Council as projects NASA should undertake in the coming decade.Studying the mechanism by which that happens will help climate scientists answer a key question: "What is the turning point at which oceans start releasing, rather than absorbing, huge amounts of heat back into the atmosphere and accelerate global warming, rather than limiting it," said Nadya Vinogradova Shiffer, SWOT's program scientist at NASA in Washington.Taking inventory of Earth's water resources repeatedly over SWOT's three-year mission will enable researchers to better trace fluctuations in the planet's rivers and lakes during seasonal changes and major weather events.By comparison, previous studies of water bodies relied on data taken at specific points, such as river or ocean gauges, or from satellites that can only track measurements along a one-dimensional line, requiring scientists to fill in data gaps through extrapolation."