May 11, 2019

Predicting Submerged Archaeology Sites in the Pacific Northwest

May 11, 2019/ webmaster

Isostatically Adjusted Paleoshorelines for Oregon and Washington: 20,000 Years of Changing Shorelines, Jon Krier

Synopsis of the GSOC Friday Night Lecture Given on April 12, 2019, with Speaker Jon Krier, MS from OSU

By Carol Hasenberg

Jon Krier’s work seeks to conduct ancient shoreline mapping in order to find possible locations of submerged archaeology sites along the western coast of North America. He combines modern bathymetry and other technological techniques to assess underwater contours with the oral traditions of indigenous tribes in his work.

Krier has recently been involved in a project along the Oregon coast for the Confederated Tribes of the Grand Ronde. The tribes’ objective in hiring the study was to determine where ancient settlements may be located on the submerged coast in anticipation of energy companies coming in to the area. They are having Krier predict where cultural resource assessments need to be done prior to any disturbances.

His work has evolved from several studies done in Denmark to evaluate archaeology and shipwreck sites. The Danish model differs from that done in the Americas by the difference in historical records and traditions. In Denmark the researchers first ask people for stories of what the land was like in the past. These can be oral or written accounts of past events. Then the researchers model the bathymetry and compare.

In the New World written history began with arrival of European settlers in the 1800’s. However, indigenous tribesmen in Alaska and the Pacific Northwest have mostly stayed in the same geographical areas since the first American people crossed the Bering Land Bridge and began the process of settling the continent. Their oral traditions stretch back over a history of several thousand years, or “time immemorial”.

Krier’s first work grew from an early fascination with the Bering Land Bridge, which included his childhood home in Nome, Alaska. Jon moved to Oregon in 2010 to begin undergraduate studies at UO. In 2018 Jon graduated from OSU with an MA in anthropology. His masters project focused on predictive modeling of submerged sites on the Beringia Land Bridge (BLB), a very large swath of land.

Krier also referred to other findings in which indigenous oral histories were confirmed with natural or human historic events. Studies have compared oral histories for natural events like the eruption of Mt. Mazama and the existence of the Bridge of the Gods. A more recent example is the finding of the wreckage of the HMS Terror and HMS Erebus, British explorer ships that set out in 1845 to find a Northwest Passage through Canada’s Arctic. Inuit oral history recorded the correct location of the sunken ships, more than 60 miles from the expected locations.

Other reports of the natural world of the past can be sifted from ancient creation legends from the oral traditions. On what English speakers refer to as the Queen Charlotte Islands, Haida Gwaii history says they came to the islands to escape advancing ice. The Nehalem Tillamook talk about ice and south wind, and the timing of the formation of the Clatsop Plains. Krier discovered the legend in an older book that was written about their tales. The Clatsop plains formed after the final retreat of the ice ages and this is also confirmed from geological studies.

Photograph of a human footprint (center) impressed into a 13,000-year-old paleosol at the Meay Channel I archaeology site on Calvert Island. Source: Sci News, March 29, 2018. Image credit: Duncan McLaren.

On Triquet Island along the central British Columbia coast, a Heiltsuk village site was found where traditional tales said it would be. This site was inhabited 14,000 years ago because it escaped inundation by the Cordilleran Ice Sheet, which covered much on British Columbia. On nearby Calvert Island, 13,000-year-old footprints were found on a beach reported by the Heiltsuk to be stable for many years.

NOAA provided the sonar data used in modeling the coastlines of the past. It was a bit of a challenge to make the ancient shoreline models because there are a lot of variables. For instance, silt and glacial deposits cover up land exposed in ancient times. One of the trickiest of the variables was to determine the glacial isostasy position of the ancient landforms. The continental glaciers represented a large mass of material, causing the land under them to depress, and the land around them to bulge upward. This bulge was greatest in the location of 150-180 kms from the edge of the ice sheet.

The final product of the study included a 15,000-year baseline coast map, which roughly coincides with oldest known settlements in the area. The bathymetry data helps Krier to delineate the drainage systems on submerged areas, which is an important part of determining potential ancient habitation sites. Krier also noted that the modern coastline dates from about 4000 years.

Looking at a map produced by Krier’s study of the Pacific Northwest coast over time, we see that far from being a relatively straight line, there were large “banks,” or portions protruding from the continental body. Krier modeled these submerged peninsulas looking for headland areas in the 10,000+ years range. West of Newport was a large peninsula now known as Heceta Banks. Loren Davis at OSU is another archaeologist doing some offshore exploration on the coast, and in 2001 a mussel shell was recovered 140 m down, in what was the Heceta Banks paleo shoreline.

In 1845, explorer Sir John Franklin set sail from England with two ships, HMS Erebus and HMS Terror, in search of a Northwest Passage across what is now Canada's Arctic. The ships and crew were last seen by Inuit on King William Island and never ret… — In 1845, explorer Sir John Franklin set sail from England with two ships, HMS Erebus and HMS Terror, in search of a Northwest Passage across what is now Canada's Arctic. The ships and crew were last seen by Inuit on King William Island and never returned to England. Their apparent disappearance prompted a massive search that continued unsuccessfully for nearly 170 years.
In September 2014, an expedition led by Parks Canada discovered the wreck of HMS Erebus in an area that had been identified by Inuit. Two years later the wreck of HMS Terror was located. Historical research, Inuit knowledge and the support of many partners made these discoveries possible. Now Inuit and Parks Canada are working together to jointly manage this fascinating National Historic Site. Source: Parks Canada website

The modern fishing ground now called the Nehalem Banks lies further to the north. Nehalem Banks was much more affected by the ice sheet than the Heceta Banks area. It was located on the forebulge and so even though it is deeper today than the Heceta Banks it also was exposed in earliest habitation times.

Another set of possible sites are offshore of Cape Meares and Cape Lookout, capes situated between the two banks. These rocky outcrops of Columbia River Basalt protrude out into the ocean and would have been much larger in the past.

There is some work to be done to increase the information to be evaluated. Current maps are not very accurate at large scales for close up work. This is because they are based on side-scan sonar surveys. This same technique was used in the 1980’s for sea floor mapping (see the previous issue of The Geological Newsletter).