Content area
Full Text
ABSTRACT
ADDITIONAL INDEX WORDS: Ice pile-ups, ice-regime, sediment/ice content, barrier islands, shoals, submerged lands act, land ownership, Supreme Court.
INTRODUCTION
A chain of barrier islands stretches along Alaska's Arctic coast from the Canning River in the east past Prudhoe Bay in the west, a distance of about 95 km (Figure 1). In 1949-50 the US Coast and Geodetic Survey charted the islands and the sea floor along this island chain. One apparently new island, "hundreds of yards long and hundreds of feet wide" and cresting 3-4 feet above sea level, was first observed during this survey (MANN, 1996). It was named Dinkum Sands after the survey launch Fair Dinkum, which carried a small punt Dinky Dinkum. Subsequent reports outlined in the present document, and my letter to the US Bureau of Land Management indicated that Dinkum Sands is no longer an island (MANN, 1996). With an offshore lease sale pending, the question of whether an island exists in the area became important in 1979. The Submerged Lands Act grants to Alaska that land under its tidal waters out to 3 miles from the coastline. Establishing the coastline at Dinkum Sands requires knowledge of the ground elevations in the area and of sea level. To acquire this knowledge, Alaska and the United States commissioned a joint study with a budget of over $2.5 million. The tasks included construction and operation of three tide gauges, with one each at Dinkum Sands, Cross Island, and Narwhal Island (Figure 1). The joint project also included surveys of the geomorphic feature Dinkum Sands several times over a 4-year period. Details of this work are provided in MANN (1996).
The precise determination of a partly submerged land surface on the sloping shore face in the Arctic is problematic because of the presence of a seasonal cover of ice and snow that undergoes almost unnoticeable horizontal movement. Movement causes warping of the ice plus crumbling, breakage, and even mixing of thin ice slabs with the shallow sea bottom. In the present report, I describe (a) my own observations and a survey of the area prior to the Supreme Court hearings in 1984, (b) my observations of Dinkum Sands made during the monitoring program by the State and Federal Governments, (c)...