Quansoo Beach: Recent Geological History
A Brief Analysis by Tim
and Alex Cohn
25 August 2000
The following analysis should be attributed to the
The work has not been reviewed or approved by anyone
The analysis presented here is limited in scope ("quick
The analysis does not consider the impact of future
climate change, sea-level rise, etc.
Over a hundred years ago, Henry Whiting reported that the South Beach of
Martha's Vineyard was rolling northward at a rate of approximately 5 feet
per year (Whiting 1888). Although the
geology of beach recedence is relatively well understood, this situation
is somewhat unusual and of sufficient practical interest -- particularly
to owners of property in Quansoo -- to justify some investigation.
In any case, land that evolves from backwoods through beachfront to submarine
property clearly deserves special treatment -- not even considering the
legal issues that it raises. The purpose of this page is to document,
in a crude way, what has occurred during the hundred years since Henry
Whiting first called attention to this phenomenon.
The Geologic History of Cape Cod and Martha's Vineyard: Some References
Fortunately, a lot of good material has already been written about the
geologic history of the Cape Cod region, of which Martha's Vineyard
and Nantucket are a part. For starters:
History of Cape Cod, Massachusetts, by Robert N. Oldale of the U.S.
Geological Survey, provides an excellent introduction.
After reading about the regional geological history, you should take
a few minutes to read the fascinating early account of Martha's Vineyard's
beaches contained in Whiting (1888); it explains
Finally, an excellent review of coastal issues affecting the Nation
can be found in Coasts in
Crisis, by S. Jeffress Williams, Kurt Dodd, and Kathleen Krafft Gohn.
The Cartographic Record of South Beach
The Island of Martha's Vineyard appears, at least in concept, on many early
maps of New England. Some of these are available on the web at http://www.vineyard.net/vineyard/history/maps.htm.
Of particular interest is the J. Reid map of 1796,
which shows that at one time all of the ponds on the South shore of Martha's
Vineyard were connected. This is consistent with reports of ice skating
along the sound from Chilmark to Edgartown. It also explains
the origins of the names for some isolated ponds such as Long Cove and
High-accuracy mapping of Martha's Vineyard began in the 19th century.
The Island has been surveyed and mapped at least three times by the U.S.
These maps have been periodically "photoinspected" and revised, most recently
in 1977. All of the maps are available from the USGS.
Aerial Photographs of Martha's Vineyard
The National Aerial Photography Program has been operating since the 1940's,
and the Island has been photographed periodically ever since.
A set of these photographs have been ordered and will be available on this
web page in the near future. For now, the best available recent aerial
photograph is from 1994 (see below).
The Rate of Beach Recedence
A quick analysis was conducted comparing
the 1887 map (right) with the 1994 aerial photograph. This reveals
that the Quansoo Beach migrated to the north by approximately 500 feet
during 107 years, for an average rate of slightly less than 5 feet per
year. This is consistent with Whiting's findings: Whiting
(1888) estimated that in the 40 years between 1846 and 1886 the beach
had "rolled" between 175 and 200 feet, an annual average of slightly less
than 5 feet.
1994 Aerial Photograph
It is also interesting to note some of the consequences: In 1887,
Chilmark Pond, Quename Cove, Blackpoint Pond, Tisbury Great Pond, and Long
Cove were connected by natural channels.
By 1942 (above), the beach had moved northward by about 250 feet and
apparently had cut off essentially all of the links. The two that
remained, connecting Black Point Pond to Tisbury Great Pond to Long Cove,
appear to have been constructed.
Various records indicate that South Beach at Quansoo has been "rolling"
northward at a fairly steady rate of approximately 5 feet per year for
the past several hundred years.
Page created 25 August 2000; Page last modified
13 September 2000
Please email comments or suggestions to Tim Cohn at: firstname.lastname@example.org