Walter Munk. Portrait of Austrian-American oceano- grapher and geophysicist, Walter Heinrich Munk (born 1917). Munk was born in Vienna and emigrated to the USA at the age of 16. He studied at the California Institute of Technology. He has held academic positions at Scripps Institute of Oceanography of the University of California. Munk's major research subject is the rotation of the Earth. In 1961, with G. MacDonald, he showed how tides, air circulation, and glaciation - all measurably affect the length of the day. Day length varies by some 0.002 seconds from summer to winter.