A massive canyon system about 621 miles long and over 3,000 feet deep in places has been discovered underneath the ice in Antarctica, according to a story on cnet.com.

Using newly acquired satellite data from sources like NASA, ESA, and the US National Snow and Ice Data Center, researchers found striations on the surface of an ice area that seemed to indicate the shape of a canyon below the surface.  The team used radio-echo sounding to confirm their suspicions, and also found a sub-glacial lake as large as 483 square miles.

The team is in the process of re-confirming the findings by using the radio-echo devices to cover the entire region by air and will complete the task later this year.

The team believes the canyon was carved by running water, but they are unclear if the canyon was formed before the area became covered by ice, or if the water running underneath the ice sheet caused the canyon to form.

Lead researcher Stewart Jamieson, from the Durham University’s Department of Geology in the UK, said it was astonishing to think that such a massive structure could have taken so long to discover.  He added this was the first evidence of a huge canyon and lake beneath the ice in Princess Elizabeth Land.

Jamieson went on to say the area under investigation is larger than the United Kingdom, but we still know so little about it, and for comparison, he says we know more about the surface of Mars than we do about Antarctica.

The research team hopes a better understanding of the landscape underneath the ice sheets will prepare us to understand how the changes in the climate will impact the ice sheet itself, and the underlying bedrock.

Study co-author Neil Ross, of Newcastle University, said the team was grateful to the various agencies that provided data and assistance in the project and said the discovery would not have been made without them and the radio-echo sounding data acquired by the ICECAP project over the past field seasons.

The team’s findings were published in the January issue of the journal Geology.