Publication Date

1989

Document Type

Dissertation/Thesis

First Advisor

Powell, Ross D.

Degree Name

M.S. (Master of Science)

Department

Department of Geology

LCSH

Ice on rivers, lakes, etc.--Illinois||Beach erosion--Illinois--Wilmette||Michigan, Lake

Abstract

During winters 1987-88 and 1988-89, the Lake Michigan icefoot complex at Wilmette, Illinois, was monitored to determine its conditions of formation and destruction, and to determine the relative importance of those factors. Icefoot-complex formation is controlled primarily by air temperature, with all ice additions to the complex occurring in subfreezing conditions. Wave- heights above 0.4 meters are a secondary facilitating factor, as is the presence of preexisting ice fragments offshore. Icefoot-complex destruction is primarily mechanical, caused by wave impacts. After breakup, ice fragments are transported from the area by longshore currents. Air temperature has only a gross correlation to ice destruction, probably due to the relatively slow speed at which ablation operates. Another secondary destructive process observed to occur is wind transport of ice fragments, which only occurs under limited circumstances. A sediment budget for the complex was prepared through sampling of the ice. The concentration of sediment in the complex is related to the type of incorporated ice. The total amount of sediment incorporated in the 1988-89 complex and transported by mechanical ice breakup was 2.6 cubic meters/meter of shoreline. In comparison, at the same time, wave and wind transport accounted for 105.4 and 1.25 cubic meters/meter, respectively.

Comments

Includes bibliographical references (pages 83-86)

Extent

viii, 89 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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