Shoreline Processes near Barrow, Alaska: A Comparison of the Normal and the Catastrophic

Abstract

The normal average yearly net transport of sediment along the Alaska coast west of Pt Barrow to the NE is 10,000 yd³, to the east of Barrow, 9,500 yd³. An Oct 1963 storm with gusts of up to 75 mi/hr, over an ice-free ocean, produced 10-ft waves and a storm surge of 11-12 ft; it moved >200,000 yd³ sediment, caused coastal flooding and >$3 million damage. If climate is warming, such storms can be expected more frequently. The normal daily tide at Barrow is about 6 in (except in storm) and an additional monthly variation of about 5 in. Storm tides of several feet are caused by rise of sea level under a low pressure area and by onshore wind. Ice damps waves and wave-generated currents. Freeze-up occurs 2 Sept- 19 Dec, breakup 17-23 July. Even when considered open and navigable, the water may have scattered ice near Barrow and sea ice a few mi offshore, which would act as a damper of waves. The northern Alaska coast is one of transgression, with the recent dominant action of coastal submergence. The gravel along beaches cannot be replaced by natural processes without a large amount of erosion. It should be left in place as protection.