Fast ice near the shoreline of McMurdo Sound. Seen here in December 1990. Among other roles, such ice protects continental ice from ocean waves and provides an important base for research. Credit: Michael Van Wort/NOAA, Public Domain
Sea ice that lasts for at least 15 days and is anchored to the coastline is called “fast ice.” Around Antarctica, fast ice protects continental ice from ocean waves, creates unique ecological habitats for everything from zooplankton to penguins, and is an important hub for research.
The conditions for the formation of thick, strong ice have historically been difficult to measure. Satellite observations provide powerful analysis of other aspects of Antarctic sea ice cover, such as extent, but are less suitable for assessing fast ice thickness.
In the Journal of Geophysical Research: Oceans, researchers provide a historical record of rapid ice thickness in McMurdo Sound off the coast of Antarctica from 1986 to 2022 and describe environmental variables that correlate with rapid ice thickness. I’m doing it.
The results could tell scientists when it’s safe to cross ice floes, and also shed light on how climate change may affect the ecosystems they support. There is.
Researchers based their study on a variety of information. Manual measurements through drill holes and simultaneous recording of internal ice and ocean temperatures allow researchers to measure fast ice thickness and infer ocean heat fluxes acting on the ice from below.
The researchers found that the ice thickness in McMurdo Sound was surprisingly stable from decade to decade, with no clear trend toward thickening or thinning the ice over the 37 years the study was conducted. .
However, on an annual basis, ice thickness varied by up to 0.7 meters. The researchers also confirmed previous findings that different climate factors act on different time scales. That is, global climate influences rapid ice formation on multidecadal time scales, whereas monthly and seasonal weather fluctuations influence year-to-year variations.
The researchers observed that three factors in particular caused the thicker fast ice: cooler temperatures, winds blowing from the south, and fewer “storms” (measurements of temperature and pressure) during the winter. There were no storms and long cold days, but winds from the south produced the thickest fast ice.
Further information: Maren Elisabeth Richter et al, “Interannual variation in Antarctic pack ice thickness in the McMurdo Sound and its relationship to climate,” Journal of Geophysical Research: Oceans (2024). DOI: 10.1029/2023JC020134
This article is republished courtesy of Eos, sponsored by the American Geophysical Union. Read the original story here.
Citation: Decades of observations reveal secrets of Antarctic fault ice (December 23, 2024) https://phys.org/news/2024-12-decades-uncover-secrets-antarctic-fast.html Retrieved January 1, 2025 from
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