Portal de Periódicos da CAPES

Pleistocene Maximum and Late Wisconsinan glacier extents across Alaska, U.S.A.

2004; Elsevier BV; Linguagem: Inglês

10.1016/s1571-0866(04)80182-9

2212-1161

Darrell S. Kaufman, William Manley,

Climate change and permafrost

This chapter summarises the results of a collaborative effort among glacial geologists working in Alaska to produce an updated compilation of state wide glacier extents. It summarises evidence used to draw glacial limits in 15 regions across the state and highlights the most significant changes from previous mapping. The chapter provides an overview of the glacial-geological record in Alaska, identifies prior efforts to synthesise data on Alaskan glacial geology and briefly discusses the broader implications of the newly mapped glacial extents. The chapter focuses on the two glacial limits that can most confidently be determined across the state: (1) the maximum extent of glaciers and (2) the Late Wisconsinan. The placement of the maximum glacial limit in many places is essentially an educated guess, based on extrapolation of limited data and guided by regional geographical patterns and general geomorphology. The extent of Late Wisconsinan glaciers is delimited more accurately. The distribution of Pleistocene glaciers largely follows that of present-day glaciers, with the most massive accumulations of ice proximal to the southern moisture sources. The maximum glacier extent was greater relative to the Late Wisconsinan for the western Brooks Range and for the Seward Peninsula than for other regions. The most extensive glaciers in the western part of the state probably grew when the adjacent continental shelves were submerged and the glaciers were preferentially nourished by a proximal moisture source that was cut off during the Late Wisconsinan.