His work won awards including the National Medal of Science, the Kyoto Prize, and induction to the French Legion of Honour.

Munk and his doctoral advisor Harald Sverdrup developed methods for forecasting wave conditions which were used in support of beach landings in all theaters of the war.

Additionally, Munk and his wife Judy were active in developing the Scripps campus and integrating it with the new University of California, San Diego.

Munk's career included being a member of the JASON think tank, and holding the Secretary of the Navy/Chief of Naval Operations Oceanography Chair.

[10] After serving 18 months in Field Artillery and the Ski Troops,[13] he was discharged at the request of Sverdrup and Roger Revelle so he could undertake defense-related research at Scripps.

In December 1941, a week before the Japanese Attack on Pearl Harbor, he joined several of his colleagues from Scripps at the U.S. Navy Radio and Sound Laboratory.

[13][9]: 3  Munk and Sverdrup found an empirical law that related wave height and period to the speed and duration of the wind and the distance over which it blows.

And then he did decide, in spite of the fact that conditions were not favorable, it would be better to go in than lose the surprise element, which would have been lost if they waited for the next tidal cycle [in] two weeks.In 1946, the United States tested two fission nuclear weapons (20 kilotons) at Bikini Atoll in the equatorial Pacific in Operation Crossroads.

Munk helped to determine the currents, diffusion, and water exchanges affecting the radiation contamination from the second test, code-named Baker.

[11][8] Six years later he returned to the equatorial Pacific for the 1952 test of the first fusion nuclear weapon (10 megatons) at Eniwetok Atoll, code-named Ivy Mike.

[9]: 25  Roger Revelle, John Isaacs, and Munk had initiated a program for monitoring for the possibility of a large tsunami generated from the test.

[23][9]: 81 In the late 1980s, plans for an expansion of IGPP were developed by Judith and Walter Munk, and Sharyn and John Orcutt, in consultation with a local architect, Fred Liebhardt.

[3][25] As Carl Wunsch, one of Munk's frequent collaborators,[26] commented:[9]: vi [Walter has] a sometimes uncanny ability to delineate the essence—that had eluded his predecessors—of a central problem.

One of his explicitly stated themes is that it is more important to ask the right questions than it is to give the right answers.In 1948, Munk took a year's sabbatical to visit Sverdrup in Oslo, Norway on his first Guggenheim Fellowship.

[10] He worked on the problem of wind-driven ocean circulation,[9]: 34  obtaining the first comprehensive solution for currents based on observed wind patterns.

Over longer times (a century or more), the largest influence is the tidal acceleration that causes the Moon to move away from the Earth at about four centimeters per year.

[29][30] In 1957, Munk and Harry Hess suggested the idea behind Project Mohole: to drill into the Mohorovičić discontinuity and obtain a sample of the Earth's mantle.

Initial test drillings into the sea floor led by Willard Bascom occurred off Guadalupe Island, Mexico in March and April 1961.

[32] However, the project was mismanaged and grew in expense after the construction company Brown and Root won the contract to continue the effort.

To trace the path and decay of the waves, he established measurement stations on islands and at sea (on R/P FLIP) along a great circle from New Zealand, to the Palmyra Atoll, and finally to Alaska.

[9]: 48  By the 1970s, there were extensive published observations of internal-wave variability in the oceans in temperature, salinity, and velocity as functions of time, horizontal distance, and depth.

Its universality is interpreted as a sign of profound processes governing internal wave dynamics, turbulence and fine-scale mixing.

"[9]: 50 Beginning in 1975, Munk and Carl Wunsch of the Massachusetts Institute of Technology pioneered the development of acoustic tomography of the ocean.

During six days in January 1991, acoustic signals were transmitted by sound sources lowered from the M/V Cory Chouest near Heard Island in the southern Indian Ocean.

These signals traveled half-way around the globe to be received on the east and west coasts of the United States, as well as at many other stations around the world.

According to Sandström's theorem (1908), without the occurrence deep mixing, driven by, e.g., internal tides or tidally-driven turbulence in shallow regions, most of the ocean would become cold and stagnant, capped by a thin, warm surface layer.

[72][73] Munk recognized that the tidal energy from the scattering and radiation of large-scale internal waves from mid-ocean ridges was significant, hence it could drive abyssal mixing.

[75][76] This work described what came to be known as "Munk's enigma", a large discrepancy between observed rate of sea level rise and its expected effects on the earth's rotation.

[92] The award was retired in 2018, and The Oceanographic Society "established the Walter Munk Medal to encompass a broader range of topics in physical oceanography.

She was an active participant at Scripps for decades, where she contributed to campus planning, architecture, and the renovation and reuse of historical buildings.