National Park Service U.S. Department of the Interior

National Register of Historic Places Program:
Archeology Month - Archeology and Climate Change

The National Register of Historic Places is the official list of the Nation's historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Park Service's National Register of Historic Places is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America's historic and archeological resources.

 

[photo] Photo from wikipedia http://en.wikipedia.org/wiki/File:Mendenhall_Glacier_pano_Aug2011.jpg
Retreating of the Mendenahall Glacier in Alaska.
Photo from wikipedia

 

Archeology and Climate Change in Alaska

In general, it would be difficult to think of a cultural resource within the Alaskan Region of the United States that is in one way or another not being impacted or in danger from climate change. The region has produced a myriad of significant archeological resources that provide tribes, parks, and researchers the opportunity to study the heritage and cultural remains of those people who faired for thousands of years in its extreme conditions.

Archeological sites in coastal areas in this region have either already been eroded or are about to be lost due to sea level rise, seismic activity,  increased storm surges, lack of sea ice, and melting permafrost. National Register listed sites  such as those within the Anangula Archeological District located on a small island in the midst of strandflats, are continually threatened by coastal erosion which has already damaged a fair portion of its northern and southern coast.  The archeological data found on the island tell the story of a human occupation that dates back to ca. 8700 years before present (BP) in an area that yielded an abundant amount of food supply through both inland or maritime hunting.  This site is particularly significant because most, and possibly all, other archeological sites located on the coast and occupied before 8000 B.P. have already been lost due to erosion.  Similar to today, the site was occupied during a time of rapid sea-level rise and contains valuable data on early Holocene human migration.  Tsunamis and extensive volcanic activity that dumped two meters of ash on the village may have triggered further migrations of the inhabitants westward along the Aleutians.  Migration is a common adaption stories between settlements that face the impeding threat of climate change.  In this case, they occupied the area during the Hypsithermal, a period of warmer and drier climate than what prevailed before.  Even today, Native Americans who have been confronted with floods produced by receding glaciers have taken drastic action to the extent of moving their settlements permanently away from the coast. 

[photo] Eroding shorelines and melting permafrost damage at Bering Landbridge National Preserve (NPS photo). NPS archeologists mapping an eroding site in Amalik Bay
http://www.nps.gov/katm/historyculture/amalik-bay.htm

Many non-coastal sites in the Alaska region are also being lost or adversely affected due to melting permafrost, increased precipitation (both rain and snow), decrease in precipitation, increased wildfires and increased erosion from rivers and streams.  Like those sites on the coast, many of these archeological properties hold some of the earliest and best preserved remains of human contact and subsidence patterns that made inhabitation of the early North American climate possible.  The National Register listed Swan Point Archeological site for example, is currently the earliest archeological site in the Alaskan Region, dating to ca. 14,500 BP. This site is situated on a relatively stable knoll in the Tanana Valley in central Alaska, but the surrounding area is experiencing rapid melting permafrost which is affecting access to the site.  Prior to about six years ago, researchers used ATVs on a dry trail to reach the site. Now one must wade through shin-high water to reach it. This site is part of the Shaw Creek Flats Archaeological District (representing three of the earliest sites in AK), which is being nominated as a National Historic Landmark.  The Swan Point Archeological Site has yielded significant information and will likely yield even more concerning the peopling of the Americas during the late Pleistocene.  It establishes the first use of the wedge-shaped core and blade technology in Alaska and is also one of the few sites found to date with evidence that humans and mammoths coexisted as interpreted by its affiliated ivory artifacts.  Further research of the coexistence of human, animal, and plants could yield insight into human adaptation of early post-glacial environments.

Amalik Bay Archaeological District is another endangered site located in Katmai National Park on the coast of the Alaska Peninsula. Currently this is the only archeological NHL within the boundary of a National Park in Alaska.  Today, the district is eroding and threatened by coastal storms as well as sea level rises.  The archeology has yielded and, in the future, is likely to yield important information for investigating the initial peopling of Alaska’s southern coastline and the dynamics of human migrations in the millennia that followed.  With evidence for human occupation going back ca. 7,600 years and continuing through much of the prehistoric period, the Amalik Bay Archeological District preserves sites representing almost a complete sequence of prehistoric human occupation for the Alutiiq region.  Located on the upper Alaska Peninsula, a natural geographic crossroads between the interior and the coast, Amalik Bay was a gateway for the widespread exchange of ideas and technological innovations, including ground-slate tools and Norton-style pottery, hallmarks in the development of coastal Eskimo economies across the far northern reaches of the continent. Currently, research questions have been aimed to find information regarding the paleo-environmental reconstruction of the entire region and human adaptation to abrupt environmental change including devastating earthquakes, rapid sea level rise, and volcanic activity. 

[photo] NPS photo This ice patch at Danali National Park illustrates the typical gentle slope and flat forefield characteristic of a site likely to yield artifacts and paleobiological materials. http://www.nps.gov/dena/naturescience/upload/IcePatch-Lee2010.pdf

“Ice patch” archeology surveys have been becoming more frequent in the past decade as rising temperatures continue to prevail in the north.  “Ice patch” archeology refers to the archeological occurrences at permanent snow and ice patch features which, unlike glaciers that move, are stable and preserve perishable materials at their location of use for thousands of years.  Most of the perennial ice patches that have produced rare organic artifacts at locations such as the National Register listed Tangle Lakes Archeological District located in central Alaska are completely melted.  In effect, organic artifacts such as wood shafts, feather fletching, leather leggings and organic paint are threatened by deterioration due to climate exposure and instances of looting.  These remains are particularly valuable because ancient organic artifacts are rarely discovered due to their deteriorating nature.  Ice patches have also exposed biological ecofacts such as ancient plant and animal remains which have given researchers an opportunity to recreate the former environments in which humans have left signs of their presence.

Archeology, through its interdisciplinary perspective, bridges the gap between the natural and social sciences.  Not only can climate change damage or destroy cultural resources themselves, but can hinder the discovery of important information encoded in the archeological record which contain insights into the dynamics of how people adapted to environmental change through a range of temporal and spatial scales.  In Alaska, these time scales span more than 14,000 years. 

References:
Anangula Archaeological District National Register Form,
The Swan Point Archaeological Site National Register Form,
Amalik Bay Archaeological District National Register Form

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