When Arctic sea ice shrank to its lowest extent in September 2012, it made headlines. At the same time, though, scientists were puzzled about a missing piece of information. They wondered exactly what volume of ice floats on Arctic waters and how exactly it compared to previous summers. Both questions would help scientists better understand how vulnerable the ice was to warming: the more volume it had, the less likely it would melt.

Now, new satellite imagery has confirmed a University of Washington analysis that has produced widely quoted estimates of Arctic sea ice volume. The findings, published online in Geophysical Research Letters, used a system called the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), which provides a 34-year monthly picture of what is currently happening to the total volume of Arctic sea ice. The program combined weather records, sea-surface temperature and satellite pictures of ice coverage in order to calculate the total volume of the ice. It then verified the results with thickness measurements from individual moorings or submarines that drift below the ice.

But these weren't the only measurements. The system also checked its results against five years of precise ice thickness measurements that were collected by a satellite launched by NASA in 2003. It also used the U.K.'s CryoSat-2 satellite's data for the year of 2010 in order to check findings.

The thickness of the Arctic's ice is, worryingly, becoming thinner every year. In fact, since the sea ice is both shrinking and thinning at the same time, summer ice volume will continue to drop faster each year. Some scientists predict that the Arctic might even be ice-free in the summer in coming years.

"Other people had argued that 75 to 80 percent ice volume loss was too aggressive," said co-author Axel Schweiger in a press release. "What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid."

As the sea ice melts, it opens up the Arctic for other pursuits such as oil exploration and shipping channels. For the first time ever, industries may be able to receive access to the "Northwest Passage" on a habitual basis. The study shows a concerning new trend for the Arctic Ocean.