The
Man and the Bank Named Stellwagen
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Captain
Henry S. Stellwagen near the end of his career.
Photo courtesy of the Stellwagen Family
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There
had been some knowledge of the area. Fishermen had called it
Middle Ground for years. Some charts had noted shallows in the
area. But it took Henry Stellwagen, a Lieutenant Commander of
the U.S. Navy on loan to the U.S. Coast Survey (the forerunner
to NOAA's Coast and Geodetic Survey) working from the US
Coast Survey Steamer BIBB, to actually map the full length
and breadth of the bank in 1854 and 1855.
He
wrote on October 22, 1854: "I consider I have made an important
discovery in the location of a 15 fathom bank lying in a line
between Cape Cod and Cape Ann -- with 40 and 50 fathoms inside
and to northward of it and 35 fathoms just outside it. It is
not on any chart I have been able to procure. We have traced
nearly five miles in width and over six miles in length, it
no doubt extending much further."
The
importance of this discovery was not lost on Alexander Bache,
the superintendent of the Coast Survey, who noted in the 1854
annual report that: "The hydrographer in Massachusetts Bay had
been rewarded for his labors by the discovery in the entrance
of an extensive bank, of which he had given the position and
defined the limits, with from ten and a half to fourteen and
a half fathoms on it, lying across the entrance, and serving
thus as an excellent mark for navigators entering this important
bay. I propose to call this, from the name if its discoverer,
Stellwagen's Bank."
View
copies of letters between Stellwagen and Bache
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SANCTUARY
TRIVIA
Accompanying
Henry Stellwagen on his surveying vessel were two other
individuals of note -- an amateur surveyor by the name
of Alexander Wadsworth Longfellow, brother of the famous
poet, and a fellow hydrographer, Edward Cordell. In 1869,
Cordell, now in charge of his own survey ship, discovered
a similar-sized bank on the west coast, which would eventually
be named after him. Today, both Cordell and Stellwagen
Banks are among the significant marine areas designated
as National Marine Sanctuaries.
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According
to Stellwagen, "I consider promulgation of this discovery as very
essential to navigators, and that the knowledge of it will highly
benefit commanders of vessels bound in during thick weather, by
day or night. By it they can not only ascertain their distance
to the eastward of the coast, but, by attention to the lead after
passing inside, a good idea of latitude may also be obtained."
This military man with a talent for hydrography was also an inventor
-- he developed a sounding device with a steel cup covered by
leather valves that could bring up specimens of the sea bottom.
Used for many years by the Coast Survey, the invention won for
him the Scott Premium Medal from the Franklin Institute.
With
his sounding device, Stellwagen not only measured the size of
the bank, but the type of sediment on and around it. Said he,
"The northern end of the bank has rocky bottom, with, however,
a slight covering of fine black sand. The middle and southern
parts are coarse white and yellow sand. The bottom inside of
the bank, in deep water is generally a green unctuous mud, or
ooze."
More
information on Stellwagen's sounding cup
Today,
we are fine tuning those observations with a detailed survey
of the seafloor in the sanctuary. New multi-beam side scan sonar
survey systems allow scientists to not only get a precise reading
of topography (depth), but backscatter of the sound source provides
information on the types of sediments.
View
the USGS backscatter map for Stellwagen Bank
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Stellwagen's
preliminary map for the newly discovered bank in Massachusetts
Bay. Map courtesy of NOAA Coast Survey.
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