Ross Ice Shelf, the largest ice shelf in Antarctica, comparable in size to France, experiences significant daily movement, posing intriguing questions for scientists studying ice dynamics in the region.
Located in the Ross Sea and extending into the Southern Ocean, the Ross Ice Shelf has garnered attention due to its remarkable daily oscillations. Scientists, led by Doug Wiens, have uncovered that this colossal ice shelf shifts approximately 6 to 8 centimeters, or 3 inches, once or twice every day. This movement, triggered by slips on the ice streams flowing into the shelf, presents a phenomenon akin to seismic events experienced along Earth’s fault lines.
The interaction between ice shelves and ice streams is a focal point for researchers, particularly concerning the stability of Antarctica’s ice shelves amidst a warming climate. Ice shelves act as barriers, obstructing the flow of glaciers and ice streams toward the ocean, thereby aiding in the accumulation of ice on the continent. However, the potential collapse of an ice shelf could remove this impediment, accelerating the flow of glaciers into the ocean and exacerbating sea-level rise.
The observed movement, attributed to slip events, reflects a significant strain on the Ross Ice Shelf. Particularly noteworthy is the stationary section of the Whillans Ice Stream juxtaposed with the creeping motion of the rest of the stream. This disparity in movement underscores the complexity of ice dynamics in the region, with some streams accelerating while others decelerate over time.
Utilizing seismographs, scientists can detect the sudden motion of ice streams, providing insights into the factors governing their behavior. The velocity of elastic waves traveling through the ice shelf aligns with expectations for guided plate waves, highlighting the dynamic nature of Antarctica’s icy terrain.
The displacement of the entire Ross Ice Shelf, spanning an area of 500,000 square kilometers, by approximately 60 millimeters during these slip events underscores the magnitude of the strain exerted on the shelf. This strain not only triggers ice quakes but also potentially enhances the deformation of the ice shelf itself.
The findings shed light on the intricate interplay between ice streams and ice shelves in Antarctica, offering valuable insights into the dynamics of these critical components of the polar ice system. As researchers delve deeper into understanding these processes, they contribute to our comprehension of the impacts of climate change on Antarctica’s ice cover and its repercussions for global sea levels.
