In a landmark study, researchers used nearly 1,000 historical photographs to reconstruct the status of Antarctic glaciers before their dramatic collapse.
This new approach made it possible to deliver insights regarding the contributions of those glaciers to sea level rise, which had never been attained previously and given stark reminders of climate change impacts.
Before the Fall: A Snapshot of History (Photo : JUAN BARRETO/AFP via Getty Images)
Before this event, the glaciers discharging into the ice shelf were poorly recorded, leaving a gap for historical data.
On the other hand, detailed efforts by United States Navy cartographers between 1946 and 2000 took more than 330,000 high-quality images of Antarctica.
Using these photos, scientists have managed to digitally reconstruct the ice sheets as they were in 1968, using a method called photogrammetry.
This method easily creates precise 3D models from the 2D images, making it now possible to establish the contribution of these ice accurately ranges to the rise in sea levels since then.
The Larsen B Ice Shelf collapse had a domino effect on the glaciers formerly feeding into it, accelerating their melt and consequent flow into the ocean.
It is called 'ice shelf buttressing' and is critical to understanding the potential future responses of Antarctica's glaciers to ongoing climate change.
These archival pictures form an essential record that allows a glimpse of the past comparable in clarity to today's satellite imagery.
Not just this, what has allowed scientists to measure how much has changed in recent decades; they can also use these pictures to predict future shifts in these fragile ecosystems.
This research, in particular, points out the significance of historical records in any studies related to environmental change.
This piecing together of the past lets us have a more lucid view of our planet's future and our responsibility toward shaping it.
Cause of diminished Antarctic ice
The decline of Antarctic ice is a complex issue; its multiple factors are part and parcel of the more significant phenomenon of global climate change.
First, there is warming in the Southern Ocean, which is thought to melt the ice from beneath.
Secondly, over some successive years, this warming has been held responsible for bringing near-historic sea-ice coverage lows in succession, indicating the remarkable shift of climatic conditions over the region.
The loss of part of this ice-shelf buttressing, following breakup events like that of the Larsen B Ice Shelf, has given way to an increased discharge to the ocean, thus contributing to sea level rise.
Moreover, declining sea-ice extent enables even more heat and moisture exchange between the ocean and atmosphere, feeding back into melting in both cases.
These things interact and build on one another to construct a self-reinforcing feedback loop, where warming begets more ice loss that begets more warming-a cycle perilous for the Antarctic ecosystem and one that contributes significantly to worldwide sea level rise.
