The Role of Tidal Currents in Melting Antarctic Ice Shelves

The melting of ice shelves in Antarctica is a well-known consequence of rising atmospheric temperatures. However, a recent study suggests that there may be another factor contributing to this phenomenon – tidal currents. Researchers from China have found that tidal currents in Prydz Bay, the third largest bay in Antarctica, may be responsible for up to 69% of basal melting on the Amery Ice Shelf. This finding challenges previous assumptions about the role of tides in the melting process and highlights the need for further research and observation.

Understanding Basal Melting

Basal melting occurs when oceanic heat and compression contribute to the melting of ice shelves. It is a complex process that is not yet fully understood. The study conducted by the Chinese researchers aimed to quantify the contribution of tidal currents to basal melting in Prydz Bay. To do this, they utilized observational data from the Amery Ice Shelf Oceanographic Research experiment and the Chinese Antarctic Expedition, as well as numerical modeling analyses.

Tidal currents are formed by the gravitational forces of the sun and moon, which cause the water in oceans and bays to rise and fall. In Prydz Bay, the tidal currents are relatively weak compared to other larger bays in Antarctica. However, the researchers found that the maximum tidal velocity occurs at the front of the Amery Ice Shelf, and the tidal kinetic energy reaches about 31% of the total kinetic energy over the outer continental shelf. These findings suggest that tidal currents in Prydz Bay may play a significant role in regulating the circulation and hydrographic properties of the area.

By analyzing the observational data and conducting numerical modeling analyses, the researchers estimated that tidal currents may be responsible for up to 69% of basal melting on the Amery Ice Shelf. However, it is important to note that the models used in the study relied on simulated velocity, as there were no long-term velocity observations in the sub-ice-shelf cavity. This may have led to overestimating the tidal contribution to basal melting. The researchers emphasize the need for more long-term observations and advanced numerical models to improve our understanding of the basal mass balance of the Antarctic Ice Sheet.

This study provides a benchmark validation for future modeling studies focused on Prydz Bay. It highlights the need for more long-term observations to accurately quantify the contribution of tidal currents to basal melting. Further research is also needed to understand the specific mechanisms through which tidal currents affect the melting process. The researchers involved in the study plan to continue collecting more long-term observations in Prydz Bay to further inform our understanding of this complex phenomenon.

The role of tidal currents in melting Antarctic ice shelves is an important area of research. The study conducted by Chinese researchers in Prydz Bay sheds light on the significant contribution of tidal currents to basal melting on the Amery Ice Shelf. However, further research is needed to refine our understanding of this process and improve current models. By gaining a more comprehensive understanding of the factors contributing to ice shelf melting, scientists can better predict and mitigate the effects of climate change on Antarctica’s ice sheets.