Earlier this year, an iceberg the size of Chicago broke off the Antarctic Peninsula. When the gigantic iceberg calved, it revealed a previously hidden 209-square-mile area of seafloor that had never been accessible to humans before.

Researchers were working off the coast of Antarctica when it happened: a gigantic iceberg about 30km long cracked off the ice sheet on January 13, revealing a swath of ocean that had not been exposed to daylight in decades.

Never seen, perhaps, but that doesn't mean forever to remain unknown. For years, the British Antarctic Survey has been flying planes over the frozen southern continent, using radar, sound waves, and gravity mapping to ascertain the shape of the bedrock sequestered below.