This is the best summary I could come up with:

Scientists have discovered a vast, hidden landscape of hills and valleys carved by ancient rivers that has been “frozen in time” under the Antarctic ice for millions of years.

This landscape, which is bigger than Belgium, has remained untouched for more than 34m years, but human-driven global warming could threaten to expose it, the British and American researchers warned.

The main way to “see” beneath it is for a plane flying overhead to send radio waves into the ice and analyse the echoes, a technique called radio-echo sounding.

When combined with radio-echo sounding data, an image emerged of a river-carved landscape of plunging valleys and sharply peaked hills similar to some elsewhere on the Earth’s surface.

The fact that retreating ice over past warming events – such as the Pliocene period, 3m to 4.5m years ago – did not expose the landscape, was cause for hope, he added.

The study was released a day after scientists warned that the melting of the neighbouring west Antarctic ice sheet is likely to substantially accelerate in the coming decades, even if the world meets its ambitions to limit global warming.

The original article contains 549 words, the summary contains 187 words. Saved 66%. I'm a bot and I'm open source!