Scientists confirmed the Conger ice shelf, which had an approximate surface area of 1200 square kilometres, collapsed suddenly around March 15.
The collapse has shocked scientists, as East Antarctica is one of the highest, coldest and driest places in the world.
However, temperatures have soared over recent weeks.
Dr Catherine Colello Walker, an earth and planetary scientist at NASA and the Woods Hole Oceanographic Institution said the collapse could herald further ice loss in the frozen continent.
“It is most likely, a sign of what might be coming.”
Why ice shelves are crucial to frozen continent
Ice shelves act like “corks” the Woods Hole Oceanographic Institution explained in the a statement.
“They ring the continent’s coast and serve as buttresses, as a buffer between the (warming) ocean and the massive interior ice sheet.
“This is the first time an ice shelf collapse has ever occurred, observable to humans, in East Antarctica, and it was completely unpredicted.”
The Woods Hole Oceanographic Institution said the loss of East Antarctica could raise sea levels by five times more than West Antarctica.
“That won’t happen for centuries, but it’s processes like this one that will eventually allow that to happen”.
The Thwaites glacier, which equals the size of Florida or Great Britain, is known as the “Doomsday glacier,” as its demise could lead to irreversible changes throughout the planet.