Mapping Stamp Sand Dynamics: Gay, Michigan

Abstract

Monitoring coastal change is vital because a high percentage of the world's population lives in close proximity to coastal areas. This paper examines a portion of Lake Superior's shoreline where coastal landscape has been shaped by the introduction of 25 billion kg of stamp sand from the copper industry and subsequent dynamics associated with longshore currents. Shoreline areal change from this movement is documented through comparison of archival and current air photos. A series of historical air photo mosaics were processed with a Geographic Information System (GIS). Sets of spatially registered, temporal map polygons were developed to illustrate and allow measurement of the areas of erosion and deposition, relevant to shoreline planning and measurement. Measurements indicate that the length of shoreline affected by the stamp sand increased by 2.4 km during a 59-year period. Measurements of area indicate a decrease of 8 ha in the same amount of time. Breadth of the stamp sand shows discernable decline of 630 m width at the original deposit area at the north near Gay, Michigan, and increase of 410 m width 1,500 m southward along the coast. The methodology and results are relevant to a diversity of linear and areal landscape considerations along shorelines (property rights, planning, conservation, etc.).