Archive for the ‘History’ Category

A monumental history   1 comment

On September 15, 2016, President Obama designated the first marine national monument in the Atlantic Ocean. The Northeast Canyons and Seamounts Marine National Monument includes two areas: one that includes four undersea mountains, called “seamounts” – Bear, Mytilus, Physalia, and Retriever; and an area that includes three undersea canyons – Oceanographer, Lydonia, and Gilbert – that cut deep into the continental shelf. These sea features have monumental histories.

Monuments map, by Leland Snyder, Office of Coast Survey

Coast Survey cartographer Leland Snyder used several data sources to create this map of the Northeast Canyons and Seamounts Marine National Monument.


Bear, Mytilus, and Physalia Seamounts were discovered by oceanographers with Woods Hole Oceanographic Institution, and they were named for small Woods Hole vessels that began making forays into the deep sea in the 1950s. The Bureau of Geographical names does not know the origin of the name “Retriever Seamount,” but NOAA historian Skip Theberge thinks it was probably discovered and named for the Cable Repair Ship Retriever, which started service in 1961 working off the East Coast. The canyons were named in the 1930s, for U.S. Coast and Geodetic Survey ships. (C&GS is the earliest NOAA predecessor agency.) Oceanographer Canyon was named for the C&GS Ship Oceanographer, which discovered many canyons incising the continental slope between the Georges Bank area and Cape Hatteras; Gilbert Canyon was named after the C&GS Ship Gilbert, which took an active part in the survey of the Georges Bank, 1930-32; and Lydonia Canyon was named for the C&GS Ship Lydonia.

The monument, which encompasses 4,913 square miles, has been the subject of scientific exploration and discovery since the 1970s. But the original discoveries of the canyons were made more than 80 years ago, when the U.S. Coast and Geodetic Survey surveyed the canyons with TNT bombs.

Yes, you read that right.

Some of the C&GS ships in the 1930s were anchored-station vessels, hanging a hydrophone over the side at a well-determined point. TNT bombs were thrown over the sides at about fifteen minute intervals. The explosion being “time zero,” the sound waves traveled through the water to the hydrophone, which in turn activated an automatic radio signal back to the survey vessel. The time interval between reception of radio signal and time of explosion, times the velocity of sound in sea water, gave the distance. This system, called “radio-acoustic ranging,” was developed by C&GS as the first non-visual survey system.

The survey of these canyons, using (for then) modern methods gave an unprecedented view of the seafloor generating debates as to the cause of the canyons, and in a larger sense, generating the birth of marine geology. Indeed, Dr. Francis Shepard, recognized by many as the “father of marine geology,” got his start on these surveys.

This excerpt from International Aspects of Oceanography, a National Science Foundation publication, was written by Wayland Vaughn of the Scripps Institution of Oceanography in 1937. He describes the contribution of both echo-sounding and the navigation system termed "radio-acoustic ranging" to the mapping of the seafloor. C&GS developed RAR and used it to survey U.S. continental margins in the 1930s.

This excerpt from International Aspects of Oceanography, a National Science Foundation publication, was written by Wayland Vaughn of the Scripps Institution of Oceanography in 1937. He describes the contribution of both echo-sounding and the navigation system termed “radio-acoustic ranging” to the mapping of the seafloor. C&GS developed RAR and used it to survey U.S. continental margins in the 1930s.


The history of these early explorations is fascinating. So as not to give it short shrift, we are going beyond our normal blog post format and including a full-length article contributed by NOAA’s historian, retired Capt. Skip Theberge.

♦ ♦ ♦

A History of Exploration and Discovery in the Northeast Canyons and Seamounts Marine National Monument

By Capt. Albert “Skip” Theberge,  Jr., NOAA (retired), Acting Chief of Reference, NOAA Central Library

The recent designation of the Northeast Canyons and Seamounts Marine National Monument is the culmination of over eighty years’ involvement in this area by NOAA and its predecessor agencies. It is no accident that the canyons in this area were named for ships of the U.S. Coast and Geodetic Survey (C&GS), NOAA’s oldest ancestor agency. Oceanographer, Gilbert, and Lydonia Canyons were named for three of the four ships that conducted surveys of the area between the years 1930 and 1932. The fourth ship, Welker, is commemorated by the naming of Welker Canyon, just to the west of the new monument boundaries, and a fifth ship, Hydrographer, was commemorated by the naming of the next canyon to the west of Welker Canyon.  These ships completed the first comprehensive survey of the continental slope in this area, using the most modern equipment available: a combination of advanced echo-sounding equipment and the radio-acoustic ranging system, the first survey-quality non-visual navigation system. This system was developed in the Coast and Geodetic Survey.

C&GS map of submarine valleys on Georges Bank, 1932

C&GS map of submarine valleys on Georges Bank, 1932


Besides being used for navigational charts, the data from these surveys was used in a number of scientific publications, first by Francis Shepard, known as the father of marine geology. Although going on to become a famous Scripps Institution of Oceanography scientist, some of his earliest work was initially published in the Bulletin of the Field Engineers of the Coast and Geodetic Survey. However, the greatest work associated with these surveys was a paper published in 1939 by the geologist A.C. Veatch and the brilliant C&GS officer Lieutenant Paul Smith. This paper was titled “Atlantic Submarine Valleys of the United States and the Congo Submarine Valley” and was Geological Society of America Special Papers Number 7. Included in this paper was a beautiful map that extended from Lydonia Canyon on its northeast corner to Norfolk Canyon off Chesapeake Bay at its southern limit. Shown on this map were thirteen named canyons as well as a number of other canyons incised in the continental shelf.

Veatch and Smith bathymetic map

This famous Veatch and Paul Smith bathymetric map from 1939 generated an ongoing interest in marine geology by showing that the seafloor was not dull and featureless.


This map served to call the attention of the geological community to the rugged and grand nature of the seafloor, previously believed by many to be bland and featureless. It also served to ignite a fierce debate in the scientific community regarding the mode of formation of canyons. There were two competing theories. The first theory was that the canyons formed sub-aerially with sea level dropping as much as 10,000 feet worldwide. The second theory was that sediment-laden density currents carved out the canyons. Both theories had influential backers but, ultimately, as a result of Woods Hole Oceanographic Institution (WHOI) sediment sampling in the early 1950s on the oceanic extension of Hudson Canyon, the density current theory won out as layers of poorly graded sands and gravels were found far at sea. This, combined with knowledge of the sequential breaking of further downslope submarine cables over a period of 13 hours following the 1929 earthquake on the Grand Banks, served to prove the concept of density currents.

The Second World War brought new studies in this area as the continental shelf and slopes of the United States were the locus of fierce submarine warfare. Woods Hole Oceanographic Institution and the Coast and Geodetic Survey combined efforts to map the location of known shipwrecks and bottom sediment types on a series of charts extending from east of Georges Bank to the tip of Florida. This was not WHOI’s first work in the area, as Maurice Ewing had conducted early seismic reflection and refraction experiments in this area before the war.

Chart 1107-A in 1943

C&GS issued chart 1107-A in 1943, showing names of canyons. This was a restricted chart (used in anti-submarine warfare) overprinted with bottom characteristics and known shipwrecks.


Following the war, WHOI sent numerous expeditions into the Atlantic and discovered three of the seamounts included in the Northeast Canyons and Seamounts National Marine Monument. These three were Bear, Mytilus, and Physalia and were named for small inshore vessels operated by WHOI. Although the earliest mention of these seamounts in the unclassified literature was in 1962, John Ziegler of WHOI first discovered and named these features in 1955 on a classified survey. A prototype Heezen-Tharp physiographic diagram that was probably produced in the mid-1950s clearly shows the New England Seamount Chain and seamounts in the vicinity of the three Woods Hole seamounts of the monument.  The fourth seamount in the monument, Retriever Seamount, was probably discovered by and named for the cable repair ship Retriever which operated off the east coast of the United States in the early 1960s.

Geological discovery and interpretation of the canyons and seamounts dominated research until the late 1960s. At this time, studies began of the dynamic oceanography of Oceanographer and other New England canyons. The first manned submersible dives into the canyon also occurred at this time, with 1966 Alvin dives followed in 1972 and 1974 by dives in the Navy’s nuclear research submersible NR-1. Oceanographer Bruce Heezen was aboard and suggested a “balanced concept in which canyons are created by some tectonic forces or drowned river valleys, are shaped and kept alive by the tides and are coursed by turbidity currents at certain long term intervals when especially large supplies of sediment are delivered to the heads of their system.” In the late 1970s and early ‘80s, there were sporadic efforts to begin studying the biology of the canyon systems, which has continued up to the present day. Since 2000, there has been a significant increase in studies related to these systems. The first dive on a seamount of the new monument was made on July 24, 1968, on Bear Seamount, by K. O. Emery in the submersible Alvin. Minimal information was obtained, but in 1974 a series of dives was made from the vicinity of Corner Seamount to Mytilus Seamount under the direction of James Heirtzler as chief scientist. In his words, this was the first time that “man had directly viewed the expanse of the earth between the Mid-Atlantic Ridge and the North American continent.” Dive 7, the final dive, was made on Mytilus Seamount; it was described as “unique” as it is capped by approximately 300 meters of shallow water reef material. As this occurs at a depth of over 3,000 meters, it is apparent that this seamount has subsided over two miles while being rafted to the northwest from its original location over the Great Meteor hotspot.

Biological studies of these seamounts did not begin in earnest until 2000, when NOAA Ship Delaware II made 20 exploratory trawls in the vicinity of Bear Seamount. Over 270 species were collected including 115 fish species, 26 cephalopod species, and 46 crustacean species. Over the next thirteen years, NOAA’s Office of Ocean Exploration and Research (OER) followed up the fisheries cruise with a number of expeditions to the vicinity of the newly designated national monument. The first of these cruises was the 2003 Mountains in the Sea Expedition which, following in the footsteps of Heirtzler years earlier, used the submersible Alvin to dive on Manning and Kelvin seamounts and conduct multibeam surveys of Bear Seamount. As opposed to the primarily geologic emphasis of the earlier dives, though, these concentrated on the remarkable biological diversity of the New England Seamount Chain. This expedition was followed by Mountains in the Sea 2004, in which the use of robotic vehicles instead of a manned submersible was used to conduct explorations. 2004 saw Retriever, Balanus, and Bear Seamounts explored and the acquisition of hundreds of spectacular photos of the seafloor. 2005 saw the North Atlantic Stepping Stones expedition which, although not studying seamounts in the national monuments, did explore a number of seamounts of the New England Chain. In 2012, NOAA ocean exploration ship Okeanos Explorer returned to the northeast continental shelf and slope area on the Northeast and Mid-Atlantic Canyons mapping expedition. This expedition was primarily concerned with multibeam mapping of the various canyons, including those in the monument, as preparation for the 2013 Northeast U.S. Canyons Expedition that investigated Oceanographer, Lydonia, and Gilbert Canyons, other large canyons of the regions, and Mytilus Seamount. This expedition marked the first use of NOAA’s 6,000 meter-rated remotely operated vehicle, Deep Discoverer and its accompanying Seirios camera sled which enabled telepresence ocean exploration. With this technology, OER was able to provide scientific and public audiences onshore a real-time view of ocean discovery in the grand canyons and hidden mountains of our Atlantic Ocean frontier.

Over eighty years of discovery and exploration, much of it accomplished by NOAA, its predecessor agencies, and academic partners have led to President Obama’s presidential proclamation of the Northeast Canyons and Seamounts Marine National Monument. The monument will assure that the unique ecosystems of this fragile area will be protected for posterity.

Posted September 27, 2016 by NOAA Office of Coast Survey in Geology, History

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Four Gulf of Mexico basins named for officers who led EEZ bathymetric mapping   1 comment

The U.S. Board on Geographic Names recently named four previously unknown basins in the United States Exclusive Economic Zone (EEZ) in the Gulf of Mexico, honoring retired NOAA officers who mapped the area in the late 1980s and early 1990s. The names — Armstrong Basin, Floyd Basin, Matsushige Basin and Theberge Basin — were proposed by Texas A&M University, based on their new compilation of bathymetry drawn largely from the NOAA multibeam mapping project conducted by now-decommissioned NOAA ships Whiting and Mt. Mitchell.

Newly named Armstrong Basin

A basin in the Gulf of Mexico was named after retired NOAA Captain Andrew Armstrong.


Retired NOAA Capt. Richard P. Floyd was the commanding officer of NOAA Ship Whiting from February 1990 to March 1992; he was followed by retired Capt. Andrew A. Armstrong III, who was CO from February 1992 to January 1994. Retired NOAA Capt. Roy K. Matsushige was commanding officer of NOAA Ship Mt. Mitchell from December 1988 to January 1991, followed by retired Capt. Albert E. Theberge, who served as CO from January to November 1991. The officers led the bathymetric mapping operations under the direction of NOAA’s Office of Charting and Geodetic Services, a predecessor of today’s Office of Coast Survey.

Cartographers rely on the Board of Geographic Names, for good reason!

Since 1890, federal cartographers have relied on the decisions of the U.S. Board on Geographic Names — the 125-year multi-agency federal program to standardize names of geographic features — that operates under the umbrella of the Department of the Interior.

“The Board on Geographic names has its intellectual roots in the earliest map-making efforts,” explains Theberge. To illustrate the need for standardization in the U.S., Theberge points to a November 7, 1805, report by the famed explorer William Clark.

“Ocian in view! O! the joy… Great joy in camp we are in view of the Ocian, this great Pacific Octean which we been So long anxious to See.”

As Theberge points out: “In one sentence, Clark gives the reasons for the Board.”

EEZ mapping project achieved policy and technical objectives for U.S.

The four NOAA commanding officers led surveys for the EEZ mapping project, which was active between 1984 and 1991. The project originated from President Ronald Reagan’s 1983 proclamation establishing a U.S. Exclusive Economic Zone, which created a 200-mile-wide nautical “belt” around the U.S. and territories, adding over 3,000,000 square nautical miles to the nation’s jurisdiction.

In response to the EEZ proclamation, both NOAA and the United States Geological Survey embarked on mapping programs. The USGS used a deep-water, very wide swath, side scan sonar system called GLORIA, which gave a qualitative picture of the seafloor somewhat akin to aerial photography; and NOAA used both medium depth multibeam sounding systems (150 meters to 1000 meters) and deep water systems (1000 meters depth to full oceanic depth), which gave quantitative (depth) values. As opposed to widely-spaced single beam trackline in deep water areas, NOAA’s program attained 100% bottom coverage with the then-new (to the civil community) multibeam systems.

The Gulf of Mexico was one region of the mapping program, as maps were produced for waters of the East Coast, Gulf of Mexico, West Coast, Alaska, and Hawaii. In a paper presented at the 1988 Exclusive Economic Zone Symposium, the goals of mapping in the Gulf of Mexico (actually applicable to all EEZ regions) were espoused:

  • Build the foundation of a marine environmental geographic information system for solving global and regional change problems.
  • Improve targeting of scientific and engineering efforts involving higher-cost, manned, submersible investigations and remotely-operated vehicle operations.
  • Better manage the living and mineral resources of the EEZ.
  • Better model the physical oceanography of the Gulf of Mexico, including factors affecting water mass movements, acoustic propagation paths, and sediment transport regimes.
  • Model geological and geophysical hazards affecting coastal regions and offshore construction.
  • Discover and/or define unique or previously unknown marine environments for designation as marine sanctuaries or protected areas.
  • Improve and enhance nautical charts and bathymetric maps.

This early multibeam mapping effort helped develop many concepts that Coast Survey later built on in shallow water multibeam charting, such as methods for correcting and calibrating beam pointing errors, use of GPS, ray-bending algorithms to account for refraction of beams, etc. Philosophically, the project also helped pave the way for the era of digital paperless survey data acquisition and processing, as EEZ survey operations significantly reduced the vast amounts of paper fathograms, printouts, and other products that accompanied classical hydrographic survey operations.

In 1992, a report by the Marine Board of the National Research Council addressed the needs of mapping the EEZ. It noted:

“EEZ mapping and survey activities of the USGS and NOAA have been impressive, especially given the limits on funding, assets, and human resources. …The current activities depend on individual efforts and assets that are, in many instances, borrowed or diverted from other projects.”

By the time the report was written, circumstances — including the grounding of the Queen Elizabeth II in Martha’s Vineyard Sound — dictated that NOAA devote more resources to inshore charting. The EEZ project was terminated but it left a legacy of new and improved methods, as well as a gentle nudge towards a paradigm shift from primarily paper data acquisition to digital data acquisition.

We still use the digital data gathered by the EEZ mapping project. During the monitoring of the Deepwater Horizon oil spill, NOAA used the data as its underlying bathymetric dataset. The spill was near Whiting Dome and Mitchell Dome, which were named respectively for their discovery by the NOAA ships Whiting and Mt. Mitchell during the EEZ project.

New project picks up where the EEZ project left off

Today, a new national deep-water bathymetric mapping project is underway, picking up where the EEZ project left off. The Office of Coast Survey’s Joint Hydrographic Center at the University of New Hampshire, along with NOAA’s Office of Ocean Exploration, is leading the bathymetric mapping work of the interagency U.S. Extended Continental Shelf (ECS) Project. Using today’s modern high-resolution descendants of the multibeam systems aboard Whiting and Mt. Mitchell, the ECS Project the ECS Project is mapping the continental slope in several regions, including the Gulf of Mexico, to establish the outer limits of the U.S. continental shelf in areas beyond the 200 nautical mile EEZ. Andy Armstrong, of recently named Armstrong Basin fame, continues to use his bathymetric mapping expertise, now conducting mapping operations for the ECS Project.

Happy 209th anniversary to the Office of Coast Survey, the oldest federal scientific organization   3 comments

The Office of Coast Survey dates from 1807, when much of the commerce between the states was by coastal shipping. And all foreign trade, especially critical to our prosperity, had to come by ship. With so many ships coming into our ports and harbors, shipwrecks were common, and it was clear the young maritime nation needed accurate nautical charts.

At the Second Session,
Begun and held at the city of Washington, in the territory of Columbia,
on Monday the first of December, one thousand eight
hundred and six.

AN ACT to provide for surveying the coasts of the United States.

Be it enacted by the Senate and House of Representatives of the United States of America, in Congress assembled, that the president of the United States shall be, and he is hereby authorized and requested, to cause a survey to be taken of the coasts of the United States, in which shall be designated the islands and shoals, with the roads or places of anchorage, within twenty leagues of any part of the shores of the United States; and also the respective courses and distances between the principal capes, or head lands, together with such other matters as he may deem proper for completing an accurate chart of every part of the coasts within the extent aforesaid.

Sec.2. And be it further enacted, that it shall be lawful for the president of the United States, to cause such examinations and observations to be made, with respect to St. George’s bank, and any other bank or shoal, and the soundings and currents beyond the distance aforesaid to the gulph stream, as in his opinion may be especially subservient to the commercial interests of the United States.

Sec. 3. And be it further enacted that the president of the United States shall be, and he is hereby authorized and requested, for any of the purposes aforesaid, to cause proper and intelligent persons to be employed, and also such of the public vessels in actual services, as he may judge expedient, and to give such instructions for regulating their conduct as to him may appear proper, according to the tenor of this act.

Sec. 4. And be further enacted, that for carrying this act into effect there shall be, and hereby is appropriated, a sum not exceeding fifty thousand dollars, to be paid out of any monies in the treasury not otherwise appropriated.

[signed] Nathan Macon, Speaker of the House of Representative
[signed] Geo. Clinton, Vice President of the United States, and President of the Senate

I certify that this act did originate in the House of Representatives.
[signed] John Beckley, Clerk

February 10, 1807
[signed] Thomas Jefferson

See the NOAA library for more resources on Coast Survey heritage

An Act

Posted February 10, 2016 by NOAA Office of Coast Survey in History

Today in WWII history: Adm. Nimitz recognizes Coast & Geodetic Survey assistance in “making possible” Japanese surrender   2 comments

On September 2, 1945, the Japanese officially surrendered to end WWII. A photo from the day, showing Admiral Chester Nimitz signing the Japanese surrender document, has his personal message: “To Rear Admiral H. Arnold Karo, USC&GS — with best wishes and great appreciation of the assistance of the U. S. Coast and Geodetic Survey in making possible the above scene. C. W. Nimitz, Fleet Admiral, U. S. Navy.”

Adm. Nimitz inscribes photo, expresses appreciation for USC&GS contributions.

Adm. Nimitz was a signatory to the Instrument of Surrender. On this photo, he inscribed his appreciation for the contributions of U.S. Coast & Geodetic Survey personnel during WWII.

The U.S. Coast and Geodetic Survey was one of NOAA’s predecessor agencies, and today’s uniformed NOAA Corps had its beginnings with WWI, when the commissioned service of the USC&GS was formed. During WWII, the Coast and Geodetic Survey sent over 1000 civilian members and over half of its commissioned officers to the military services. (See The World Wars.) Coast Surveyors served as hydrographers, artillery surveyors, cartographers, army engineers, intelligence officers, and geophysicists in all theaters of the war. Civilians, on the home front, produced over 100 million maps and charts for the Allied forces. Eleven members of the USC&GS gave their lives during WWII. 

In recent remembrance of the service and sacrifice of those men and women, Cmdr. Matt Wingate, commanding officer of NOAA’s Marine Operations Center ‒ Pacific Islands, recently wrote this report:

Fireworks lit up the Honolulu night on August 15. Seventy years ago — August 15, 1945 — Emperor Hirohito broadcast news of Japan’s surrender to the Japanese people — and the world. As a result, August 14 (because of the international dateline) and 15 are forever known as VJ Day or “Victory over Japan Day.”

Peace Fireworks

Aug 15, 2015, Ford Island, Hawaii — The “Peace Fireworks” with NOAA’s new Inouye Regional Center silhouetted on the right.

To honor this historic event, the U.S. Navy and the cities of Honolulu, Hawaii, and Nagaoka, Japan, celebrated seventy years of peace with a solemn ceremony and spectacular fireworks. (Nagaoka is the home town of Admiral Yamamoto, the key planner behind the December 7, 1941, attack on Pearl Harbor.)

Commemorative Japanese Zero plane flies over Hawaii during celebration of peace.

Aug 15, 2015, Ford Island, Hawaii — A restored Japanese Zero flies over NOAA Ship Oscar Elton Sette in commemoration of seventy years of peace between Japan and the United States.

As I watched the fireworks with shipmates aboard NOAA Ship Oscar Elton Sette, an overwhelming sense of pride and humility descended. Proud to be witnessing such a historic event, proud to be part of this amazing agency and its legacy, and also humbled by history. What a difference 70 years can make. Take a look at the historic photo with Admiral Nimitz’s signed note. I hope you get goose bumps at what he wrote to the U.S. Coast & Geodetic Survey director, Rear Admiral Karo. That’s a proud chapter of our legacy!

Something happened recently that also made me proud of our mariners. I recently met the chief of staff for Joint Base Pearl Harbor Hickham. We were scheduled to meet for 30 minutes, but the meeting extended to almost an hour because the commander was so intrigued with NOAA’s mission and the mariners who sail NOAA ships. The amount of time NOAA mariners spend at sea was especially impactful on him. As I left him, I was proud of our mariners and their salty heritage. His admiration for NOAA’s mariners was palpable.

I hope NOAA mariners hold that feeling in your work vests, and pull it out when needed. Stay focused, stay safe, and be proud of your efforts. Others certainly are.

What does the age of the survey mean for nautical charts?   2 comments

Alaska’s nautical charts need to be updated — we all know that. The diagram below shows the vintage of survey data currently used for today’s charts in Alaska. The graphic includes all surveys done by NOAA’s Office of Coast Survey (and its predecessors), and some limited data acquired by other agencies, i.e., the U.S. Coast Guard. Areas that are not colored in have never been surveyed or have data acquired by another source — from Russia or Japan, for instance — before the U.S. was responsible for charting in that area.

Vintage of Alaska survey

What are the differences between data collected in 1900, 1940, or 1960? Let’s take a look at a…

Brief Historical Sketch of Survey Technologies

Nautical charts have a lot of information, but mariners especially are concerned with two major components: water depths (known as “soundings”) and obstructions (like underwater seamounts or wrecks).

Different eras used different technologies to find, measure, and determine the position of the two components. Note that adoption of new systems does not happen abruptly; rather, new technologies are phased in as techniques and equipment improves.

Measuring Water Depth (Soundings)

3.7 million years ago to present day: sounding pole

It isn’t inconceivable that the earliest humanoid, Australopithecus afarensis, used sticks to gauge water depths before crossing streams and rivers. People still do it today.

Egyptian use of sounding pole

Note the ancient Egyptian on the far right, using a sounding pole.

~ 2000 B.C. to 1930s: lead line

As good as they were for their eras, 19th and 20th century surveyors faced technological challenges. The first challenge was accounting for gaps between depth measurements. The second was the inability to be totally accurate in noting the position of the measurement. (In other words, a specific location out in the ocean may be 50 feet deep, but a surveyor must also accurately note the position of that specific location.)

Casting a lead line

This surveyor is casting a lead line.

Early Coast Survey hydrographers measured depths by lead lines — ropes with lead on one end — that were lowered into the water and read manually. Even though soundings were generally accurate, coverage between single soundings was lacking. And we need to remember that this was before the age of GPS. While sextants gave accurate positions when a hydrographer could fix on a shoreline feature, the further offshore the survey, the less accurate the position.

(Interesting fact: Hydrographers still use lead lines occasionally, in some circumstances — but not for a complete survey.)

There have been variations on lead lines through the centuries. From 1492 to the late 1870s, for instance, mariners used hemp rope for deep-sea soundings.

(Interesting fact: Christopher Columbus and Ferdinand Magellan each tried to measure mid-ocean depths with about 1,200 feet of hemp rope. Neither one of them found the sea bottom.)

In 1872, the hemp was replaced by small diameter piano wire (again, primarily for deep-sea work), and the weight of the lead was increased. Later, hydrographers added a motorized drum to wind and unwind the line, with a dial to record the length of the line.

(Interesting fact: In 1950, the British ship Challenger used piano wire in the first sounding that established Mariana Trench as the deepest place on earth.)

20th century to the present: echo sounders

comparison of survey technique coverage

Compare the bottom coverage achieved by the different survey methods.

1918 to 1990s: single beam echo sounder

Sonar came into its own in 1913. The first echo sounders (also known as “fathometers”) had single beams that measured the distance of the sea floor directly below a vessel. The echo sounders were able to take many more depth measurements than was possible with the lead line, but the technique still resulted in gaps between the lines where the beam measured the water depth.

The U.S. Coast and Geodetic Survey (a NOAA predecessor agency) adopted this acoustic sounding technique in 1923, installing it on USCGS Ship Guide. But full-fledged change didn’t happen right away. These early sounding systems were too large to install on survey launches used in harbor and inshore work, so from 1924 until the early 1940s many surveys were still conducted with a lead line, and many were totally acoustic — and some were hybrid, using soundings from both methods, depending on coverage area and seafloor configuration.

→ 1940: U.S. Coast and Geodetic Survey fully adopts single beam echo sounding technology

The development of smaller “portable” fathometers for shallow waters, about 1940, was a primary impetus in the obsolescence of lead line as survey technology and the adoption of acoustic systems. The development of World War II electronic navigation systems for bombing purposes led to the development in 1945 of the first survey-quality electronic navigation systems, which allowed for more accuracy in positioning.

1964 to current day: multibeam echo sounder

By mid-century, scientists were increasing the beams projected by the echo sounder, to get a broader swath of measurements. The multibeam echo sounder was developed for the Navy in 1964, but it remained secret until the late 1970s when commercially available systems were developed.

Coast Survey first used a MBES technique, called the “Bathymetric Swath Survey System,” in 1977 on NOAA Ship Davidson, for depths ranging from 160 to 2,000 feet. In 1980, NOAA Ship Surveyor installed a deep-water MBES system called “Sea Beam,” for depths from 1,600 to 33,000 feet.

About 1986, Coast Survey began using GPS to calibrate medium-frequency navigation systems while operating in the far reaches of the United States Exclusive Economic Zone. By the mid-1990s, GPS was the primary control for accurate positioning.

→ 2000: Coast Survey fully adopts multibeam surveying

By 2000, Coast Survey was performing full-coverage multibeam hydrographic surveys for charting purposes. NOAA survey ships now use multibeam echo sounders that measure navigable coastal depths from 45 to 1,000 feet. For shallower and more constricted waters, the ships deploy hydrographic survey launches with multibeam echo sounders that efficiently and safely survey areas from 12 to 200 feet deep. These systems make it possible to acquire 100% sea floor coverage in the survey grounds (excluding ultra-shallow, near-shore, or obstruction areas).

Finding Underwater Obstructions

1880s to early 1990s: wire drag

Surveyors used wire drag, not as a sounding system but as a way to look between the sounding lines to find obstructions to navigation and establish safe navigational channels. The first documented wire drag was conducted in the 1880s, in French Indochina, Gulf of Tonkin area, attaching the wire to buoys at each end and letting it drift with tidal currents.

Around 1900, the U. S. Lake Survey developed the technique of using a ¼-mile wire drag between two boats. In 1903, Coast Survey began using the technique, and within a few years was using it extensively in Alaskan waters as they looked for pinnacle rocks. Coast Survey’s Alaska wire drags were up to 3.5 miles long. (Initially, “least depths” over discovered obstructions were determined by lead line, then acoustic means and, ultimately, by divers with depth/pressure gauges.)

wire drag operations

Survey vessels conduct wire drag operations.

1960 to present day: side scan sonar

Side scan sonar is essentially the sonar equivalent of an aerial photograph. It improves the ability to identify submerged wrecks and obstructions. Evolving from submarine detection sonars of World War I and World War II, side scan sonar was fairly well developed by 1960, when the United Kingdom Hydrographic Office started using it regularly with their surveys.

→ 1990: Coast Survey fully adopts side scan sonar for East Coast and Gulf Coast surveys

NOAA Ship Whiting used the technology in 1984-1985 for approaches to New York. U.S. Coast Survey fully adopted side scan sonar (in place of wire drag) in the early 1990s.

lowering the tow fish for SSS

Side scan sonar operations use “towfish” like this one, lowered into the water and towed from the back of the vessel.

SSS image of wreck

Side scan sonar captures images of objects, which improves the ability to identify submerged objects.

Today’s Charts Reflect Different Tech Eras

Each of NOAA’s 1000-plus nautical charts, even today, can contain information collected by any or all of these sounding and positioning techniques.

Most nautical charts are an amalgamation of geospatial information collected using different techniques at different times. For example, one area of a specific current-day nautical chart might be based on a lead line and sextant survey conducted in 1910, and another area on the same chart might be based on a multibeam and GPS survey conducted in 2010. If we dig deep enough, we will probably find a sounding or two from the 18th century British explorer, Captain James Cook.

NOAA cartographers mold this disparate information so that it fits together as a coherent representation of the geographic area.

So when was the data acquired for the chart you’re using? NOAA cartographers add a “source diagram” to large-scale charts. (See the diagram on the current chart 16240, pictured below.) Check yours. That will give you the years of the surveys… and now you have a better idea on the technology used by the surveyor.

source diagram 16240

This is the source diagram on nautical chart 16240.

NOAA dedicates memorial at Absecon Lighthouse   Leave a comment

Sunday, June 21, was World Hydrography Day, a day set aside to recognize the important work of hydrographers.  Measuring and describing the physical features of oceans, seas, and coastal areas is essential not only to the safe navigation of the everyday mariner, but to our nation’s economic development, security and defense, scientific research, and environmental protection.

Absecon lighthouse with NOAA flag

The NOAA flag flies at the Absecon Lighthouse during the memorial dedication. Photo by David Hall

This year’s observation was particularly noteworthy for NOAA, as we honored the lost crew members of the U.S. Coast Survey Steamer Robert J. Walker, by dedicating a memorial at the Absecon Lighthouse in New Jersey.

On June 21, 1860, the Robert J. Walker was hit by a commercial schooner while transiting from Norfolk to New York after months of surveying in the Gulf of Mexico. The ship sank 12 miles offshore, as they were heading to the Absecon Lighthouse after they were hit. Coast Survey lost twenty crew members that night, and another man died from his injuries the next day, in the largest single loss of life in Coast Survey and NOAA history.

Dr. James Delgado, director of maritime heritage at NOAA’s Office of National Marine Sanctuaries, described the events of that long-ago day, and spoke of the partnership between NOAA and the New Jersey diving community in identifying the previously unidentified wreck.

Steve Nagiewicz, co-director of the Robert J. Walker Mapping Project, recognized a dozen private citizens who assisted with the project, as he talked about the importance of collaborative efforts in conserving the nation’s maritime history.

Recognizing private citizens

Steve Nagiewicz (center) and Dr. James Delgado (second from left) recognized the collaboration between NOAA and private citizens in identifying and conserving the Robert J. Walker wreck. Photo by Dawn Forsythe

Rear Admiral Gerd Glang, director of NOAA’s Office of Coast Survey, dedicated the memorial.

“With this memorial duly dedicated, we are assured that future generations will know what happened off these shores,” Glang said. “They will remember the sacrifices made to make our nation’s coasts safe.  And they will give these crew members a permanent honor that was so long denied.”

A historic hydrographer’s bell rang for every crew member that lost their life, similar to the memorial service held two years ago.

Glang, Delgado, and Oliver

Rear Admiral Gerd Glang dedicated the Walker memorial, with James Delgado and Cheryl Oliver. Photo by Dawn Forsythe

On the grounds of the Absecon Lighthouse you will now find a memorial consisting of a NOAA commemorative geodetic marker, as well as a plaque honoring the lost crew members, placed in a compass rose on the grounds outside the lighthouse entrance. The plaque is an iconic image that was proposed by NOAA Corps Basic Officer Training Class 102, in a design project headed by Lt. Cmdr. Jeff Shoup.

In expressing NOAA’s appreciation for all involved in the project, Glang thanked two people in particular. First, he noted the persistent efforts of Skip Theberge, our NOAA historian and a retired NOAA commissioned officer.

“I would dare say that very few people in NOAA even knew about the Robert J. Walker until Captain Theberge told us about this tragic event,” Glang said. “It is because of his knowledge — and especially his persistence in telling the story — that NOAA made the effort to find and identify the Walker.”

Glang also offered special appreciation to Cheryl Oliver, exhibit manager for the Office of National Marine Sanctuaries and the senior program advisor for NOAA’s Preserve America Initiative. She is also the president of the U.S. Coast and Geodetic Survey Heritage Society. Cheryl was NOAA’s moving force behind the development of this memorial.

Cheryl Oliver and James Delgado

NOAA Preserve America Initiative advisor Cheryl Oliver and Maritime Heritage Program Director James Delgado at the Robert J. Walker interpretive sign at Absecon Lighthouse. Photo by David Hall

The Robert J. Walker was positively identified in 2013 after NOAA Ship Thomas Jefferson set aside a day to survey the site while it was in the area conducting operations after post tropical storm Sandy. The ship’s physical scientists were guided by historical accounts in the 1860 Coast Survey Annual Report. Then, using the Thomas Jefferson data and armed with additional information from researchers and archaeological advisers, divers pinpointed the exact location and confirmed the ship’s identity.

NOAA would like to express our appreciation to U.S. Coast Guard Station Atlantic City (in particular, Seaman Philip Zinna and Fireman Apprentice Christopher Barreras) for presenting the colors at the event.

A color guard from U.S. Coast Guard Station Atlantic City presents the colors. Photo by David Hall

A color guard from U.S. Coast Guard Station Atlantic City presents the colors. Photo by David Hall

Jean Muchanic

Absecon Lighthouse Executive Director Jean Muchanic welcomed the crowd of 50 people to the Walker memorial dedication. Photo by David Hall

Coast Survey adds historical publications to online collection   5 comments

by Melissa Volkert, Coast Survey communications associate

NOAA’s Office of Coast Survey has added a wide range of publications to our Historical Map and Chart Collection. The collection of publications consists of annual reports, catalogs, United States Coast Pilot, Notes on the Coast, and special reports.

Collection logo

The collection contains over 35,000 documents from the earliest days of the U.S. Coast Survey.

  • Annual Reports are yearly publications, from 1837 to 1965, that detail the many scientific and technological activities of Coast Survey.
  • Aeronautical charts, U.S. nautical charts, charts of the Philippines, and the old U.S. Lake Survey charts are detailed in Catalogs.
  • The Coast Pilot collection carries two centuries of volumes, from a 1796 version of the American Coast Pilot, through the 1800s and 1900s, until the 2012 versions of the U.S. Coast Pilot.
  • Written in 1861 by the Coast Survey while Superintendent Alexander Bache served on the Blockade Strategy Board, Notes on the Coast were instrumental in the Union naval strategy during the Civil War.
  • When geodetic, hydrographic, geophysical, and oceanographic methods were hard to find in annual reports, over 400 Special Reports, issued between 1898 and 1956, made the information easier to disseminate.

These publications provide context to the tens of thousands of maps and charts in the collection. Use the “Search Images” and “Search Publications” pages to explore the historic documents.

As an example, consider the great naturalist John Muir, whose 179th birthday is this month. He was a guide and artist on the Survey of the 39th Parallel across the Great Basin of Nevada and Utah from 1874 to 1877.

One result emerges: the 1875 Annual Report. This report notes, on page 62, that John Muir recorded the geological and botanical characteristics of Mount Shasta in Northern California. A “related maps” option, showing maps and other images mentioned in the publication, will be to the left of this result. In this case, the related maps include a map titled “Sketch Showing the Progress of the Survey on the Atlantic Gulf of Mexico and Pacific Coast of the United States with Sub Sketch Showing the Progress on the Pacific Coast.” This particular map was continually updated as new areas were surveyed and discovered. 1875 was the first year that Mt. Shasta was recorded on it.

You can also use the information from an image to locate a publication. This month marks the 99th anniversary of the 1906 San Francisco earthquake. Using Search Images on the Historical Map and Chart Collection:

Since this map is from 1907 and there are no images from 1906, assume findings after the earthquakes were not published until 1907.

  • Search publications for the Annual Report of 1907.
  • When the report is opened, use the “Ctrl+F” search function (press Ctrl & F together)
    • Type California in the search bar that appears at the top right.
    •  California will be highlighted every time it is stated in the document.

On page 67, there is a section entitled “Earth Movements in the California Earthquake of 1906.” This section ‒ that highlights new vs. old triangulation, and the permanent displacements of the areas affected ‒ states, “…the effects of the earthquake of April 18, 1906, indicated that there had been relative displacements of the earth’s surface from 2 meters (7 feet) to 6 meters (20 feet) at various points near the great fault accompanying the earthquake.”

chart 1

chart 1 Continued

The tables indicate the permanent displacements of various points caused by the earthquake of 1906. These permanent displacements were determined by comparing the positions of identical points upon the earth’s surface as determined by triangulation before and after the earthquakes in question. (Discover how the U.S. Coast and Geodetic Survey aided the recovery of the San Francisco earthquakes of 1906 by reading the 1907 Annual Report.)

The Historical Map and Chart Collection documents Coast Survey’s discoveries throughout history. Make your own discoveries in the collection, and let us know if you have any comments, questions, or concerns.

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