Tower-High Channels Gouge Antarctic Ice
July 23, 2012 --
This week Google debuted a new set of panoramic images from the South Pole. Taken in partnership with on-site researchers from the University of Minnesota’s Polar Geospatial Center, these interactive views shed light on remote locations such as Ernest Shackleton’s early shelter and the Adélie penguin rookery. The images were captured using off-the-shelf equipment that included a digital SLR camera with a fisheye lens, said Alex Starns, a Google technical program manager for Street View whose work covers operations in Asia Pacific and Antarctica. Brad Harried, a researcher with the Polar Geospatial Center, took the latest photos. “Brad would often carry extra batteries in his pocket and use a chemical hand warmer to keep them from freezing,” Starns said. “It’s a little challenging to operate the camera wearing thick winter clothes and mittens.” Explore the frigid Antarctic landscape in this slide show of high-resolution images.
The South Pole Telescope building shown here contains an enormous scientific instrument that took more than 30 engineers and scientists to construct. “The South Pole Station is actually at a really high altitude,” Starns said. Located 1.7 miles above sea level, the telescope is used by a team of scientists seeking to answer crucial questions such as “How old is the universe?” Since the South Pole has such clear atmosphere, it’s an ideal location for observing the thermal radiation that fills our universe. Starns hopes that Street View users who interact with the new images from Antarctica will be excited to learn more about the continent. He also wants them to have a greater appreciation for the explorers of 100 years ago and modern researchers, he said. Particularly the challenges inherent in a place NASA scientists used to prepare the landers for conditions on Mars. ANALYSIS: 100 Years Ago Today: Scott Reaches South Pole
Anglo-Irish explorer Ernest Shackleton survived what seemed like certain death. His first attempt to reach the South Pole in 1901 nearly killed him. In 1908 he returned, getting even closer to the South Pole. Although Norwegian explorer Roald Amundsen got there first in 1911, Shackleton was still determined. His ship Endurance would get trapped in the ice, forcing the crew on an epic adventure to safety. New images show the entire interior of Shackleton’s 1908 hut at Cape Royds. “Having this immersive imagery of the supply depot they built really reinforces the sense of just how incredible that journey was,” Starns said. Reading materials remain on the beds, tossed aside as if their owners will be back momentarily. And yet the objects inside hut have stayed in place for more than a century. “His
was unique because they had some early photographic equipment on board,” Starns said of Shackleton. “In the hut you can still see some of the photographic chemicals that they used to develop their film.” Photographer Frank Hurley’s images from the Endurance expedition would become famous. HOWSTUFFWORKS: Can You Vacation in Antarctica?
A 50-foot-long wooden cabin was built in 1911 at Cape Evans on Ross Island to house several dozen men. British explorer Robert Falcon Scott used this building as a base for his Terra Nova expedition to the South Pole, but he and his team ultimately reached the pole weeks after Amundsen. Scott and the four other men in his party died in the frozen wilderness while attempting to return. A letter found with his body read, "Had we lived, I should have had a tale to tell of the hardihood, endurance, and courage of my companions which would have stirred the heart of every Englishman." Although the cabin has remained largely unchanged since Shackleton locked it up in 1917, scientists have to regularly keep it from being swallowed by ice and snow. "You look at the food and the equipment that they brought and imagine how isolating and how lonely it must have been down there," Starns said, adding that he couldn’t imagine spending years eating tea biscuits and gravy. "It’s amazing to me that not only did these men do this, but many of them volunteered for it." NEWS: Two Aussies Reach South Pole Unaided
Back in 2010, Google first unveiled Street View images taken from Half Moon Island on the northern edge of the Antarctic Peninsula. Visitors from cruise ships that stopped there helped take the panoramic photos at the time, Starns said. Instead of a human, the Street View icon turned into a little penguin. The Adélie penguins at a remote rookery on Cape Royds aren’t accustomed to humans taking their pictures, but they seem more focused on soaking up the summer sun. From here the waters of McMurdo Sound are visible. Adélie penguins use the sun to navigate from land to the sea, according to scientific data from the Polar Conservation Organization. Unlike the humans in Google’s shots, none of the penguins have blurred faces to protect their identities. “If we get any blurring requests from them, we’ll be sure to tend to them,” Starns joked. ANALYSIS: Paralyzed Athlete Sit-Skis to the South Pole
Flags from the nations that signed the Antarctic Treaty encircle the Ceremonial South Pole. In 1959 the original treaty among 12 nations included provisions stating that Antarctica would only be used for peaceful purposes and ensuring continued scientific research there. Since then, the list of signatories has grown to 50. Besides flags, the Ceremonial South Pole is marked by a pedestal with a reflective globe on top. In the background stands the Amundsen-Scott South Pole Station, an American scientific facility. When the Google panoramic images were shot on the polar plateau, the conditions weren’t just windy -- the temperature was negative 60 degrees F. The ice that the station is built on moves annually so the geographic South Pole location is in a different position every year, Starns said. "The ceremonial pole always stays in the same place." VIDEO: Frozen Planet: Journey to the South Pole
Channels nearly as tall as the Eiffel Tower gouge into the undersides of floating ice in western Antarctica. The recently discovered channels could influence how quickly Antarctic ice sheets slip into the sea, melt, and contribute to rising sea levels.
Torrents of water from melting ice sheets may carve the approximately 250-meter (820-foot) tall and equally wide channels. The channels start where geographers calculated that melt water would run off the solid ground of Antarctica and under the floating Filchner–Ronne Ice Shelf. This suggests that melt water moves along a distinct course like a river beneath the kilometer-thick ice sheet, as opposed to a thin layer beneath the entire sheet.
Satellite image of the ice shelf channel (MODIS Mosaic of Antarctica (MOA) Image Map / Anne Le Brocq)
Understanding how these channels form could alter the way scientists model melting ice and help them understand events such as when a massive chunk of the Filchner–Ronne Ice Shelf broke away and shattered in less than 24 hours during January of 2010. That chunk was larger than the state of Rhode Island.
“If we are to understand the behavior of the ice sheet, and its contribution to changes in sea level, we need to fully understand the role of water at the base of the ice sheet,” said lead author Anne Le Brocq of the University of Exeter in a press release. “The information gained from these newly discovered channels will enable us to understand more fully how the water system works and, hence, how the ice sheet will behave in the future.”
A schematic diagram indicating the approximate scale of one of the ice shelf channels, similar in height to the Eiffel Tower, and Tower Bridge of London in width. (Anne Le Brocq)
Once that hidden river of melt water reaches the sea, it forms a plume and warms the surrounding salt water. The warmed waters then wears a channel into the floating ice of the Filchner–Ronne Ice Shelf of western Antarctica.
The process seems like the inverse of how a canyon forms on dry land. Except instead of water burrowing a channel down into the Earth, the warm water carves a channel up into the ice shelf.
However, since all of this occurs beneath hundreds of meters of ice in one of the most inhospitable environments on Earth, scientists must use satellite images and radar measurements from airplanes to estimate the how the hidden ice behaves as it melts away.
Scientists had observed the channels before, since they leave a distinctive line on the surface of the ice sheet. However, Le Brocq and her team have interpreted the channels as signs of hidden rivers of melt water.
Nature Geoscience published this new explanation of the melt water channels.
TOP IMAGE: A massive piece of the Filchner–Ronne Ice Shelf breaking off in January of 2010 (NASA, Wikimedia Commons)