GIS-based geomorphologic study of Presque Isle Peninsula, a compound lacustrine barrier-spit system along the south-central Lake Erie margin

摘要

The Presque Isle peninsula is a sandy barrier-spit system situated along the south-central Lake Erie coast. This investigation focuses on landform succession along its eastern terminus, where nautical charts and aerial images chronicle morphologic change over the last century. A conceptual framework of this recent terrain evolution provides a blueprint for understanding the process-landform interactions responsible for constructing the compound peninsula over the late Holocene. Presque Isle is compartmentalized into four distinct en echelon strandplains, each comprised of multiple beach ridges of similar orientations, heights and spacing. These strandplain segments are separated by topographically prominent ridgelines that extend across the width of the peninsula and obliquely truncate landward paleoshorelines. The processes responsible for this landform juxtaposition are exemplified by recent spit growth and decay along Presque Isle's eastern terminus, where net lateral accretion has extended the peninsula by similar to 0.8 km(2) since the early 1900s. Truncation of newly formed ridge morphologies here since the 1990s provides a reference frame for understanding broader peninsular evolution, as reflected in Presque Isle's morphological segmentation. Episodes of spit accretion and low elevation beach-ridge formation sequentially construct strandplains with little internal heterogeneity in way of beach-ridge spacing and height. Net-depositional episodes are subsequently punctuated by extensive erosion and the formation of high-elevation ridgelines at oblique angles to paleoshorelines. While this process is demonstrated over the recent similar to 100 years as a function of human-altered coastal hydrodynamics and sediment-supply reductions, potential linkages between older erosive landforms and major lake-level transgressions are inferred and could potentially be elucidated upon continued research. (C) 2016 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.