Whaling Log Books Reveal Depth of Arctic Ice Loss

Arctic ice fronts from the early 19^th century were far more advanced than they are today, according to whaling log analyses from University of Sunderland researchers, giving scientists a clue to just how much climate change is affecting this region.

As part of the ARCdoc research project, scientists analyzed historical logbooks recorded by explorers, whalers and merchants during epic expeditions between 1750 and 1850, including famous voyages such as Parry's polar expedition in HMS Hecla and Sir John Franklin's lost journey to navigate the Northwest Passage.

Interestingly, these documents have provided the ARCdoc team with the most detailed map of sea ice fronts before greenhouse gas emissions became a global concern.

Some 60 whaling logbooks revealed the depth of ice loss in the Arctic, and that the ice was far more advanced than it is today.

"Significantly this is the first time we have ever had direct observational information on the ice fronts in the North Atlantic and Davis Straits area before 1900," Dr. Dennis Wheeler said in a statement.

"As a result of this data, you can begin to build up a clearer picture of climate change, before human impact begins to exercise any control on the global climate, this is the Arctic under natural weather conditions," he added.

To understand how the data relates to today's ice cover decline, Phd Student Matthew Ayre had to translate the whalers' archaic terminology into the first ever sea ice dictionary in standard 21^st Century observational vocabulary.

"Apart from modern-day research vessels, these are the only books in history from ships which seek out the ice edge in great detail and follow it," he explained. "They describe various type of ice from 'loose' to 'heavy'; using this data I was able to map the ice edge, which has never been done before in any great detail because it melts and freezes every year."

The research team believes this newly found data can possibly lead to the origins of climate change today, whether it is the result of solar influences, volcanoes or internal changes in oceanic circulation.

"Those answers could give us the key to understanding the climate of the past and that means if you want to predict the future climate, you can do so with a little bit more confidence than we do now," Wheeler said.