It almost feels like science fiction: a 28-foot long, 2,200-pound robotic submarine that can fit through a 30-inch ice borehole. But observers in Tahoe this past week can attest to the realness — and world-class engineering — of the Sub-Ice Rover (SIR) created by DOER Marine of Alameda for North Illinois University. The craft is designed to explore the ocean underneath the half mile of frozen water known as the Ross Ice Shelf in Antarctica. To clear the borehole, SIR is designed to collapse to a diameter less than 30 inches.
Once beneath the ice, SIR expands and produces an array of high tech sensors and cameras which blast terabytes of data up the 2-mile cable to the control center. These instruments will ultimately seek to collect data about ice melt beneath the Ross Ice Shelf to better understand conditions at the interface between seawater and the base of the glacial ice, as well as investigate the sea floor and layers of sediment beneath. In the event of an emergency power loss beneath an ice sheet, hydraulic pumps return SIR to its collapsed form so it can be retrieved through the borehole.
“The robotic submarine undergoes a Transformer-like change in its shape as it prepares for ‘flight mode’ in the seawater,” said Reed Scherer, an NIU Board of Trustees professor of geology. “It’s an impressive piece of technology that should produce some amazing science.”
At Tahoe, SIR is being used to study the the West Tahoe Fault, located on the lake floor along its entire western shore, which is believed to cause large earthquakes every 2,000 to 4,000 years. Lake Tahoe is the second deepest lake in the United States and, as such, carries additional earthquake-induced tsunami hazard.
“The goal is to capture the first-ever high definition images and subsurface sediment profiles of the fault,” said Gordon Seitz of the California Geological Survey.
These exciting engineering feats in underwater exploration allow us to better understand our oceans by exploring some of the most extreme environments on earth. Hats off to DOER and NIU for a successful test of the SIR and we’ll be keeping an interested eye on the program as it progresses to the Ross Ice Shelf.