Ellis, Gary D. (Division of Historic Preservation and Archaeology)
INDIANA SHIPWRECK RESEARCH AND SITE EVALUATIVE STRATEGIES
Shipwrecks are a unique class of cultural resources. Random but dynamic marine
environmental effects such as ice, wave, and sand action on Lake Michigan may
largely influence the extent and direction of shipwreck site degradation in a
predictable fashion. Assessment of the site deposition process requires a thorough
evaluation of marine environmental impacts to, first, understand their interrelated
sets of effect and, secondly, understand the dynamic nature of those effects on
the shipwreck degradation process. The Division of Historic Preservation and Archaeology
is testing for such effects on four large Lake Michigan shipwreck sites (Pat Herner/Unknown
1, Muskegon, Car Ferry No. 2, and Unknown 4) to develop more efficient site evaluation
strategies. Test data collected to date support the Hypothesis that late 19th
and early 20th century and larger late 20th century man-made groyne structures
placed into the lakebed may disrupt the normal Northeast to Southwest flow of
bottom materials and result in substantial bottom depletion. The net effect of
this disruptive action on shipwreck site context is an alteration in the direction
of the horizontal plane of deposition. An understanding of groyne size, marine
environmental factors, and subsurface geology is therefore essential to the formulation
of Lake Michigan shipwreck site evaluations and our ability to predict the extent
and direction of the site degradation process.
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