By Alister Doyle, Environment Correspondent
OSLO (Reuters) - A pre-Viking woolen tunic found beside a thawing glacier in south Norway shows how global warming is proving something of a boon for archaeology, scientists said on Thursday.
The greenish-brown, loose-fitting outer clothing - suitable for a person up to about 176 cms (5 ft 9 inches) tall - was found 2,000 meters (6,560 ft) above sea level on what may have been a Roman-era trade route in south Norway.
Carbon dating showed it was made around 300 AD.
"It's worrying that glaciers are melting but it's exciting for us archaeologists," Lars Piloe, a Danish archaeologist who works on Norway's glaciers, said at the first public showing of the tunic, which has been studied since it was found in 2011.
A Viking mitten dating from 800 AD and an ornate walking stick, a Bronze age leather shoe, ancient bows, and arrow heads used to hunt reindeer are also among 1,600 finds in Norway's southern mountains since thaws accelerated in 2006.
"This is only the start," Piloe said, predicting many more finds.
One ancient wooden arrow had a tiny shard from a seashell as a sharp tip in an intricate bit of craftsmanship.
The 1991 discovery of Otzi, a prehistoric man who roamed the Alps 5,300 years ago between Austria and Italy, is the best known glacier find. In recent years, other finds have been made from Alaska to the Andes, many because glaciers are receding.
The shrinkage is blamed on climate change, stoked by man-made emissions of greenhouse gases from burning fossil fuels.
The archaeologists said the tunic showed that Norway's Lendbreen glacier, where it was found, had not been so small since 300 AD. When exposed to air, untreated ancient fabrics can disintegrate in weeks because of insect and bacteria attacks.
"The tunic was well used - it was repaired several times," said Marianne Vedeler, a conservation expert at Norway's Museum of Cultural History.
The tunic is made of lamb's wool with a diamond pattern that had darkened with time. Only a handful of similar tunics have survived so long in Europe.
The warming climate is have an impact elsewhere.
Patrick Hunt, a Stanford University expert who is trying to find the forgotten route that Hannibal took over the Alps with elephants in a failed invasion of Italy in 218 BC, said the Alps were unusually clear of snow at 2,500 meters last summer.
Receding snows are making searching easier.
"I favor the Clapier-Savine Coche route (over the Alps) after having been on foot over at least 25 passes including all the other major candidates," he told Reuters by e-mail.
The experts in Oslo said one puzzle was why anyone would take off a warm tunic by a glacier.
One possibility was that the owner was suffering from cold in a snowstorm and grew confused with hypothermia, which sometimes makes suffers take off clothing because they wrongly feel hot.
(Editing by Jeremy Gaunt.)