Cox spent the next four years working with the U.S. Geological Survey. After World War II, his career path lead him to accomplishing a good deal of research in hydrogeology, earthquake and tsunami research, and the environment. In 1946 he returned home to work for the Hawaiian Sugar Planters Association (HSPA). At HSPA, he was put in charge of the water development and research program of water and geology. For the next 14 years, Cox worked on Arno Atoll, Western Samoa, the Marshall Islands and the Marianas. He was the first to define the sigmoidal mixing curve in a fresh water lens, which he discovered by using a series of sampling tubes.
Cox was good at recognizing needs that could be taken care of by science. After the 1946 Aleutian Islands earthquake created a destructive tsunami, he wanted to make a wave-based warning system for tsunamis. He wanted to know the height and velocity of quake-generated waves, what time they would arrive, what direction they would come from, and what the destruction impact may be. In 1946, 1952, 1957, 1960, and 1964 Cox gathered data from tsunamis that struck Hawaii.[3] His data later became are part of today's Pacific Tsunami warning system.[1] In the early 1960s, Cox became a professor of geology at the University of Hawaii, remaining in that position until 1985.[1][2]
In 2002, Cox received a lifetime achievement award from the Hawaii Academy of Science for his contributions to science and education.[2] Cox died of cancer on April 21, 2003.
