1939 chart of the Caribbean by Navy Hydrographic Office showing state of knowledge of bathymetry of the Caribbean and surrounding seas.

1939 chart of the Caribbean by Navy Hydrographic Office showing state of knowledge of bathymetry of the Caribbean and surrounding seas.

1939 chart of the Caribbean by Navy Hydrographic Office showing state of knowledge of bathymetry of the Caribbean and surrounding seas.

Spectacular cross-section of the Mid-Atlantic Ridge clearly showing median valley obtained as the result of soundings taken on the German research vessel METEOR. This profile and the accompanying paper by Gunter Dietrich clearly establishes Dietrich as the first to recognize the continuity of the median valley of the Mid-Atlantic Ridge. 1938 original publication.

Profiles surmising the continuity of what are now called abyssal hills in the vicinity of the Mid-Atlantic Ridge. Illustration strikingly similar to tracing continuity of magnetic anomaly pattern. Produced by Gunter Dietrich 1938.

Title page of "Some Morphological Results of the Cruise of the "METEOR" January to May 1938" by Gunther Dietrich. Published in International Hydrograph ic Review 1939. This article clearly establishes Gunther Dietrich as the first to note the median valley of the Mid-Atlantic Ridge. Pp. 52-55.

2nd page of "Some Morphological Results of the Cruise of the "METEOR" January to May 1938" by Gunther Dietrich. Published in International Hydrograph ic Review 1939. This article clearly establishes Gunther Dietrich as the first to note the median valley of the Mid-Atlantic Ridge. Pp. 52-55.

3nd page of "Some Morphological Results of the Cruise of the "METEOR" January to May 1938" by Gunther Dietrich. Published in International Hydrograph ic Review 1939. This article clearly establishes Gunther Dietrich as the first to note the median valley of the Mid-Atlantic Ridge. Pp. 52-55. Note the final paragraph of this page.

4th page of "Some Morphological Results of the Cruise of the "METEOR" January to May 1938" by Gunther Dietrich. Published in International Hydrograph ic Review 1939. This article clearly establishes Gunther Dietrich as the first to note the median valley of the Mid-Atlantic Ridge. Pp. 52-55. Dietrich here describes the parallel undulations marching off the crest of the main ridge.

A very small-scale map of the world ocean produced by the International Hydrographic Bureau in 1939. Perhaps because of the patterning, this map has a somewhat odd appearance.

Josephine Bank as contoured by Albert Defant in 1939 from acoustic soundings.

Section of 1939 North Pacific chart 5486 by Navy Hydrographic Office showing hundreds of seamounts, the true configuration of the Aleutian Trench, and some of the southern seamounts of what became known as the Emperor Seamount Chain extending north from the vicinity of Midway Island.

Southeast section of 1939 North Pacific chart 5486 by Navy Hydrographic Office showing use of name Albatross Plateau for East Pacific Rise leading into Gulf of California. It was not until 1960 that H.W. Menard popularized the name East Pacific Rise.

Northeast section of 1939 North Pacific chart 5486 by Navy Hydrographic Office showing few of the seamounts surveyed by the C&GS during the years 1925-1939. See images map00126-map00128.

C&GS Chart 5101A, 1939, a prototype chart incorporating bathymetry acquired with RAR navigation by the C&GS out to oceanic depths. This chart was meant for navigation by following bottom contours. No other chart like this was ever produced as WWII intervened and the use of electronic navigation systems became widespread. The C&GS surveyed the continental margin of the U.S. by 1939.

The famous A.C. Veatch and Paul Smith map of the Mid-Atlantic continental slope which attracted great attention from the scientific world as it showed the results of precision radio acoustic ranging navigation and acoustic sounding. With the exception of Hudson Canyon, none of the other canyons were known at the time of publication of this map.

Harold Murray of the C&GS published this pioneering study of undersea mountains 1941. Many of the seamounts depicted on this chart were flat-topped seamounts later termed guyots by Harry Hess of Princeton.

Systematic mapping of the Gulf of Alaska by C&GS ships going to and from their Alaska nautical charting surveys led to the discoveries shown in images map00126 and map00128.

Flat-topped seamounts, later termed guyots, as noted by Harold Murray of the C&GS.

The discovery survey of Astoria Canyon off the Oregon coast. The lines of dots are lines of soundings navigated by means of radio-acoustic ranging, the first precision navigation system to eliminate the need for visual signals. This system was developed by the C&GS in the 1920's and used until WWII. Many discoveries were made because of it.

Monterey Canyon as published by George Davidson in 1897. This canyon was the second canyon ever discovered, Hueneme Canyon being first in 1855 and Monterey Canyon in 1857. In: "The Submerged Valleys of the Coast of California", Proceedings of California Academy of Sciences, Series, Vol.1, No. 2.

Hueneme Canyon as published by George Davidson in 1897. This canyon was the first submarine canyon ever discovered and was found as the result of United States Coast Survey hydrographic surveys in 1855. In: "The Submerged Valleys of the Coast of California", Proceedings of California Academy of Sciences, Series, Vol.1, No. 2.

Gulf of Mexico bathymetric map ca. 1888. All deep soundings are from work of the Coast and Geodetic Survey Steamer BLAKE. This map is one of the first to have relatively high density sounding information. The Coast Survey had taken thousands of soundings which were culled down to produce this map.

Gulf of Mexico bathymetric map ca. 1888. All deep soundings are from work of the Coast and Geodetic Survey Steamer BLAKE. This map is one of the first to have relatively high density sounding information. The Coast Survey had taken thousands of soundings which were culled down to produce this map. This map is reproduced in Alexander Agassiz's "Three Cruises of the BLAKE."

Perhaps the first three-dimensional image of a portion of the deep ocean. This map was produced from soundings primarily obtained by the C&GS Steamer BLAKE. An early rendition of this model is found in the C&GS Annual Report for 1884. This image is found in Alexander Agassiz's "Three Cruises of the BLAKE" published in 1888.

The Mendocino Escarpment as compiled by Harold Murray of the Coast and Geodetic Survey and reproduced in the Bulletin of the Association of Field Engineers in 1938. This is the first hint at the nature of what later were termed fracture zones by H.W. Menard in the 1950's.

Davidson Seamount, the first undersea feature to be officially termed a seamount by the U.S. Board on Geographic Names. This feature was surveyed by the C&GS in in 1933 and named in honor of the great Coast Survey West Coast pioneer George Davidson, 1825-1911.

This excerpt from International Aspects of Oceanography, an NSF publication, was written by Wayland Vaughn of the Scripps Institution of Oceanography in 1937 and describes the contribution of both echo-sounding and the navigation system termed Radio-Acoustic Ranging (RAR) to the mapping of the seafloor. RAR was developed by the C&GS and used to survey U.S.continental margins in the 1930's.

Names and features overlay to map produced by International Hydrographic Organization as shown in image map00119. Note tracing of ridges on this 1939 overlay.

The prototype 3-D image of the seafloor developed by Heezen and Tharp. Note the similarity to the Veatch and Smith map in image map00125. The Veatch and Smith map had been produced as a 3-D relief model by the Braund Reliefograph, a machine developed within the C&GS to produce relief models for WWII bombardiers and pilots.

Portion of the Pacific Ocean physiographic map published by H. W. Menard in his 1964 publication 'Marine Geology of the Pacific."

Portion of map showing axis of Mid-Atlantic Rift Valley as interpreted by Bruce Heezen, Marie Tharp, and Maurice Ewing

Portion of physiographic diagram of Mid-Atlantic Ridge by Bruce Heezen and Marie Tharp

Overlapping spreading center at 12 54 North Latitude on the East Pacific Rise.

3-D view of Zealandia Bank.

3-D view of West Rota Volcano.

3-D view of the continental slope and Cape Fear Diapir on the continental slope off North Carolina. This map also shows a huge submarine slide with its headwall noted by the scarps on the left of the image.

Bathymetric map of Blake Ridge Diapir

Ocean trenches and volcanic arcs of the western Pacific Ocean from the Equator to 40 North

The Southern Mariana Back-arc Spreading Center showing location of a large hydrothermal plume

3-D view of Astoria Canyon, west of the Columbia River entrance showing locations of science transects (appear as colored ribbons on canyon walls)

Full disc map of Pacific Ocean showing location of Submarine Ring of Fire Expeditions from 2002 through 2006

3-D view of Pioneer Seamount and Pioneer Canyon on the California coast showing cable route to Pioneer Seamount hydrophone installation.

3-D view of Seamount-X.

3-D view of Ruby Seamount.

3-D view of Northwest Rota Volcano.

3-D view of an un-named bank and the slopes of Lisianski Island in the Northwest Hawaiian Islands. The tops of these features are in shallow water or break the surface so no data is available giving the impression of hollow seamounts.

3-D view of Northwest Eifuku Volcano.

3-D view of Nikko Volcano.

3-D view of Lyman Seamount. North Atlantic Stepping Stones 2005 Expedition. The map shows the entire East Corner Rise seamount complex, tentatively named Lyman Seamount.