How climate change is leading to archeological discoveries

The Herald Scotland

a day ago

If it weren't for climate change, the wreckage might never have been recovered.
Those who worked for more than a year to identify the Earl of Chatham credited an uptick in stormy weather and new, unusual wind patterns for its discovery. The accelerating transformation of the coastline, known as the "cradle of shipwrecks," could lead to similar finds in the future, they say.
Such discoveries are happening in many other places, too.
As the planet continues to warm, causing glaciers to melt and sea levels to rise, scientists say discoveries like the one found on the Scottish island of Sanday are becoming increasingly common across the globe.
"It's a double-edged sword," said James Delgado, a maritime archeologist who has studied wreckages for more than 40 years. "There are more discoveries happening, climate change being a factor in that, but we're also seeing things ... that we discovered in the past that are now disappearing."
Shipwrecks galore
Coastal erosion has long led to the surfacing of old shipwrecks, but the number of vessels turning up has "intensified" as global temperatures have increased, said Delgado, who wrote the book "The Great Museum of the Sea: A Human History of Shipwrecks."
Since 1992, the global sea level has risen nearly 4 inches, according to data from the National Aeronautics and Space Administration. Scientists estimate that every inch of sea level rise equates to about 8.5 feet of beachfront loss across coasts.
Higher sea levels also mean stronger storm surges.
"We're seeing more dramatic churn on beaches during storms and that is causing the stripping away of the sand and other things that have been covering up these shipwrecks for decades," said Delgado. "More storms and higher sea levels have really started to bring them out of hiding."
The same year the Earl of Chatham was discovered in Scotland, a storm in Massachusetts exposed a wrecked schooner from 1909, another on North Carolina's Outer Banks's revealed the remains of a boat from 1919 and storms in Maine resurfaced yet another 18th century vessel on a beach.
The hurricanes Matthew in 2016 and Irma in 2017 eroded Crescent Beach in St. Augustine, Florida, helping lead to the 2020 discovery of a Civil War ship. A couple walking along the beach spotted the wooden planks of the Caroline Eddy, a Union supply ship that was heading toward Philadelphia in 1880 when it was damaged by a giant wave.
Treasures hidden in the ice
As the climate warms, melting glaciers have also begun to reveal frozen artifacts from thousands of years ago.
Dramatic melting of ice in Norway's high mountains in 2006 led to a boom in findings. Since then, archeologists have collected more than 3,000 items, spanning 6,000 years of history, from the nation's glaciers and ice patches as part of an initiative called Secrets of the Ice.
Humans have hunted reindeer and traveled along the Norwegian mountain ranges since the Stone Age. Julian Robert Post-Melbye, who has worked on the program since 2011, said items found in the ice have given historians a more vivid understanding of what life was like back then.
The artifacts are literally frozen in time.
"They look like they've been lost for 10 days, but they've been there for 4,000 years," Post-Melbye said.
Archeologists have found birch bark containers with wax candles still inside them. They've found dogs with collars that fell into the ice. They've analyzed horse manure from 800 years ago to discover what the animals ate and the pollen count at the time, Post-Melbye said.
"All these ice artifacts are just traces of a very rich and diverse communities and society stretching thousands of years that we had no, or virtually no possibility of studying 20 years ago."
'Artifacts are getting destroyed'
For Post-Melbye, any excitement about the influx of new archeological finds - and what they mean for understanding the past - quickly gives way to a more potent feeling of despair.
It's hard to ignore what the artifacts mean: "6,000 years of ice has been melting away during the last 20 years in Norway," he said.
While the changing climate is leading to more discoveries, it's also destroying some existing archeological sites and leading to increased challenges for researchers.
Post-Melbye said a team of about six archeologists in Norway is running against the clock each year to collect newly un-frozen artifacts from 70 glacial sites before they dry up, crack or blow away in the wind.
The longer items are exposed to the elements, the more they degrade.
"There's no way we can get to every site," said Post-Melbye. "We know every year artifacts are getting destroyed."
In other areas of the world, increased rain and rougher seas are wearing down previously preserved historical sites.
For instance, the Bouldnor Cliff, a submerged prehistoric settlement from the Stone Age off England's southern coast, has experienced four meters of erosion in 10 years, according the Maritime Archaeology Trust, a charity in the United Kingdom. Researchers are racing against time to rescue perfectly kept artifacts - from flint tools to hazelnuts - found at the underwater site.
A worm-like marine mollusk has also now migrated to the Baltic Sea, where it is eating ships that have otherwise stayed intact in the cold, brackish waters, Delgado said.
He sees the onslaught archeological finds and the increasing preservation challenges brought on by climate change as "canaries in the coal mine."
"Maybe them also being victims to climate change is yet another reminder that we need to do something to try to slow the progression of what's happening," he said.