A nearly 100-year history of East Antarctic aerial photos has given a unique perspective to the region’s history amid the greatest challenge for the southernmost continent.
Combining historical photos, including some dating back 87 years, researchers have compiled a short-term evolutionary history of glaciers in East Antarctica, generally considered the more stable Antarctic half.
The photography of 2,000km of coastline overlayed with current satellite technology shows two contrasting stories.
First, East Antarctica has remained particularly stable for much of the past century – withstanding much of the ice loss seen on the continent’s western side.
The analysis shows the east has grown slightly since 1937 with the aid of increasing snowfall. But more recent satellite imagery paints a different picture – where like the rest of Antarctica, warming air and ocean temperatures threaten to eat away at its critical land ice and glaciers.
“Early observations of glaciers are extremely valuable as they give us a unique insight into how the ice has evolved through a varying climate and whether current changes in the ice exceed the glaciers’ normal cycle of advance and retreat,” says lead researcher Mads Dømgaard, a glacier researcher at the University of Copenhagen.
Nazi’s Norway and nearly no analysis
Dømgaard’s research group all but fluked the analysis.
The oldest aerial photos used to piece together East Antarctica’s glacial history were captured by a Norwegian whaler during a 1937 expedition and stored at the Norwegian Polar Institute, along with maps charted from the images.
But the invasion of Norway by the Nazis at the start of World War II meant the maps were never published and the photos remained under lock and key.
Only through reading records about the expedition were Dømgaard and his colleagues able to unlock and study the photographic records.
“It’s fantastic that these old images can be used to generate new research almost 100 years after they were taken,” says Dømgaard.
The Norwegian photos were the only records used in the study but provide a crucial starting point for the 9-decade history of the region.
165 Australian survey photographs of the same region were also included in the study, filling out the middle of the data set (from 1950-1974).
The findings are published in Nature Communications.
