The major factor in natural coastal rock art submersion is climate change, the warming of the earth by the addition of greenhouse gases to the atmosphere. “Global mean sea level has risen about 8-9 inches (21 - 24 centimeters) since 1880, with about a third of that coming in just the last two and a half decades. The rising water level is mostly due to a combination of meltwater from glaciers and ice sheets and a thermal expansion of seawater as it warms. In 2019, global mean sea level was 3.4 inches (87.61 mm) above the 1993 average - the highest annual average in the satellite record. From 2018 to 2019, global sea level rose 0.24 inches (6.2 millimeters).” (Lindsey 2020) Sites that currently lie just a few inches to a few feet above mean sea level will inevitably become submerged as rising waters continue to creep up year by year.
One rock art site listed by Tiwary (2014) is the Alta Fjord site in Norway which, although currently exposed, he expects to be submerged by rising sea-levels. “The World Heritage Rock Art in Alta is a rich cultural monument consisting of several carvings and paintings localized in the inner parts of Altafjord in Finnmark, Norway. The rock art in Alta was made over a period of time from 4200 B.C. to 200 A.D. After a few years it may get submerged into the sea.” (Tiwary 2014)
“The Alta site is at the head of the fjord, and is very well protected from the swells of the Norwegian Sea. The depth of the fjord increases rapidly from about 60 metres close in shore to more than 400 metres further out in the fjord. It was used as an anchorage by the German battleships Tirpitz and Scharnhorst in 1943 during WWII.” (Hitchcock 2019)
“At the end of the last ice age, the land ‘rebounded’ after the bulk of the ice melted, and so this part of Norway slowly lifted by a process known as isostasy. The ice sheet reached its greatest extent and thickness 20,000 years ago, and most melting occurred between 16,000 and 10,000 years ago. This uplift did not stop when the ice had melted, it continues to this day.” (Hitchcock 2019)
This isostasy will be competing with the sea-level rise caused by global warming, but the projections for sea-level rise suggest that it will win the competition and that the Alta petroglyphs are eventually as doomed as the other sites I have listed.
Waianae coast, Oahu, Hawaii. Internet photo, Public Domain.
There are many other rock art sites that sit near sea level that will become underwater rock art sites with continued sea-level rise. One site is a recently discovered petroglyph site on Hawaiia’s Waianae coast on Oahu. “Archaeologists from the Hawaii Department of Land and Natural Resources and the U.S. Army have been working together to record and document the petroglyphs; which now number at least 17 figures.” (Sci-News 2016) The figures stretch over sixty feet of beach. These figures are on the beach and were covered by sand until recently and, depending on wave action and storms, may be covered again. A few inches of sea-level rise, however, will submerge them.
Orca petroglyph, Wrangell, Alaska. Photo Peter Faris, August 2, 2001.
Another major petroglyph site which will inevitably be covered by sea-level rise is Petroglyph Beach at Wrangell, Alaska. Produced by the Tlingit people it is representative of much of the rock art on the northwestern coast of North America.
Mask petroglyph, Wrangell, Alaska. Photo Peter Faris, August 2, 2001.
“While Tlingit rock art (especially petroglyphs) may sometimes have been made to attract the salmon, the figures include clan crests, ancestors, mythological figures and sailing ships, as well as symbols of wealth or victory. Tlingit rock art may, like the elaborate totemic figures on poles and house screens, serve as illustrations of important events, mythic or historical, in the clan traditions and so bear witness to the achievements, wealth, or supernatural powers obtained by the clan ancestors.” (De Laguna 1990:215) Of the rock art at Petroglyph Beach, the figures are pecked and carved into basalt boulders on the beach. Many of them seemingly consist of masklike faces, but the famous orca there is undoubtedly a clan figure as described above. Again, if left as they are, a foot or two of sea level rise will submerge almost all of them.
Undoubtedly many other locations like this exist. It has not been my intention to present a complete catalog of threatened rock art sites, but to present a different angle to rock art conservation, one not commonly considered. Next week I will discuss some rock art sites that are underwater as a result of human, not natural, activity.
NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.
Additionally - I wish to express my gratitude to Dr. Sachin Tiwary for his permission to quote his study as well as reproduce images from it.
REFERENCES:
De Laguna, Frederica, 1990 Tlingit, pp. 203-228, in Handbook of North American Indians, Volume 7, Northwest Coast, Wayne Suttles, editor, Smithsonian Institution, Washington D.C.
Hitchcock, Don, 2019, Norwegian Rock Art - Alta Fjord, Don’s Maps, https://www.donsmaps.com/norge.html
Lindsey, Rebecca, 2020, Climate Change: Global Sea Level, National Oceanic and Atmospheric Administration (NOAA), https://www.climate.gov
Staff, 2016 400-Year-Old-Petroglyphs Found on Hawaii Shoreline, Ausust 11, 2016, www.sci-news.com
Tiwary, Sachin Kr., 2014 Underwater Rock Art: In Global Context, En Rupestreweb, http://www.rupestreweb.info/underwaterrockart.html
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Wonderful work. Every begginer should learn this way of work.
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