Related: Alarming heat waves hit Arctic and Antarctica at the same time This means that the glacier was retreating almost three times faster than it was between 20, when it was receding at a rate of around 0.5 miles (0.8 km) per year, according to satellite data. "It really blows my mind how beautiful the data are." However, the eye-catching grooves on the seafloor are also cause for concern, he added.īased on the spacing of the ribs, the researchers estimated that when the Thwaites glacier was anchored on the bump, the icy mass retreated at a rate of between 1.3 and 1.4 miles (2.1 and 2.3 km) per year. "It's as if you are looking at a tide gauge on the seafloor," study lead researcher Alastair Graham, a geological oceanographer at the University of South Florida, said in the statement. (Image credit: Alastair Graham/University of South Florida) The seafloor map of the bump shows the parallel grooved lines, or ribs, spread across the grounding point's surface. During neap tides, high tides are lower and low tides are higher.) (During spring tides, high tides are higher and low tides are lower. The varying depths and spaces between the ribs match the cycle of spring (opens in new tab) and neap tides, with the glacier being moved farther and with greater force during the former. Each rib represents a single day collectively, the lines map out the gradual movement of the glacier over a period of around 5.5 months. These ribs are actually imprints that were left behind as the high tide briefly lifted the glacier off the seafloor, which slightly nudged the ice mass further inland before the low tide lowered it back down. The spaces between the ribs range short and wide, between 5.2 and 34.4 feet (1.6 and 10.5 m) apart, but they are most commonly around 23 feet (7 m) apart. These strange-looking grooves, which are also known as ribs, are between 0.3 and 2.3 feet (0.1 and 0.7 m) deep. The resulting map showed that the bump is covered with around 160 parallel grooved lines that give it a barcode-like appearance. Researchers mapped out the bump using the underwater robot Rán (named after the Norse goddess of the sea), which spent around 20 hours scanning a 5-square-mile (13 square kilometers) section of the former grounding point. "We should expect to see big changes over small timescales in the future." Reading between the lines "Thwaites is really holding on today by its fingernails," study co-author Robert Larter, a marine geophysicist with the British Antarctic Survey, said in the statement. This scenario could become more likely in the future if increasingly warmer waters melt away the glacier's guts, according to the statement. Researchers say the new map is like a "crystal ball" showing us what could happen to the glacier in the future if it becomes detached from its current grounding point - which is around 984 feet (300 m) below the surface - and gets anchored to a deeper one like the bump. Sections of seafloor that grab hold of a glacier's underbelly are known as "grounding points," and play a key role in how quickly a glacier can retreat. The Thwaites Glacier extends well below the ocean's surface and is held in place by jagged points on the seafloor that slow the glacier's slide into the water. Due to climate change, the enormous frozen mass is retreating twice as fast as it was 30 years ago and is losing around 50 billion tons (45 billion metric tons) of ice annually, according to the International Thwaites Glacier Collaboration (opens in new tab). The glacier gets its ominous nickname because of the "spine-chilling" implications of its total liquidation, which could raise global sea levels between 3 and 10 feet (0.9 and 3 meters), researchers said in a statement (opens in new tab). or the entirety of the United Kingdom - that is slowly melting into the ocean off West Antarctica (opens in new tab). Thwaites Glacier is a massive chunk of ice - around the same size as the state of Florida in the U.S.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |