Coastal Erosion Responses for Alaska - the National Sea Grant ...

Coastal Erosion Responses for Alaska: Workshop Proceedings
likely causal. Bluff erosion on the scale of tens of meters per year was occurring
even 100 years ago in the eastern Beaufort Sea, as de Leffingwell observed.
High rates of erosion occurred throughout the 1970s between the Colville
River and Prudhoe Bay, as documented by Erk Reimnitz and Peter Barnes
for USGS, based only on map comparisons. One concrete result of the BIG
STORMS project is the very detailed hazard map of the 1963 storm, available
to residents on the Web, which has engendered considerable interest at community
meetings.
Wainwright and Point Lay also have erosion problems. At Wainwright,
people can retreat as bluff erosion proceeds with permafrost melting. Beach
nourishment at Wainwright may have had some ameliorating effects in the
short term. Point Lay, at its re-founding in the 1970s, elected to move to the
mainland, away from the eroding barrier island: at least one problem was
solved!
Although not presently under siege by erosion, Point Hope suffers from
the same free-floating global change angst that has captured most north Alaska
communities: fear of entrapment without an evacuation route and the possibility
of storm surge flooding through the beach ridge swales near town. Point
Hope, home to nearly 900 people, moved east in the mid 1970s, about 2 km
from its ancestral locale of Tikigaq at the eroding north margin of the spit.
Fierce storms have occurred repeatedly at Point Hope, although the storm
of record occurred in 1893, when a surge of at least 3 m flooded the town site.
Point Hope community members have had occasion and partial funding to
employ a number of folk-based and half-baked engineering remedies to the
perennial erosion on the north margin, that now lacks any structures to protect
(except for the unprotected margin of the concrete air strip. Erosion acts differentially
on the north margin of the Point Hope spit, related to the percentage of
silt and frozen ground that is higher within the middens of Tikigaq (dating to
AD 1400-1950) than in the dunes that cap the older settlement of Ipiutak on the
oldest ridges of the spit. An incompletely realized revetment, consisting of sizable
Nome boulders, was laid atop several stretches of the north shore of Point
Hope in 1997. Funding (via a no-bid contract to Tikigaq Corporation, NSB resolution
#41-97 dated June 3, 1997) and design for this project arose from within
the North Slope Borough with minimal (if any) oversight from the Army Corps
or other agencies; apparently no EIS was prepared for this project. The original
design parameters were not met, so that a series of groins were not placed
along with the rock revetment. Nonetheless, the revetment, as it stood in 2004,
did not offer protection to the airstrip—instead it exposed it to erosion—and
only extended landward of a portion of the two threatened archaeological sites.
One of the foremost concerns to Point Hope residents involves the erosion of
archaeological sites employed as cache pits to properly season muktuk. While
cultural pejoratives should be respected, it seems extravagant and ill-advised