Antarctic glaciers that resisted effects of climate change
A new study has found that the effects of , which are apparent in other parts of the Antarctic continent, are not yet observed for glaciers in the western Ross Sea coast. The typical pattern of glacier advance and retreat has not changed along the western Ross Sea coast, in contrast to the rapidly shrinking glaciers on the Antarctic Peninsula. The study found that the drivers of glacier response to climate - such as air temperatures, snowfall, and ocean temperatures - have not changed much over the past half century in the region. The major glaciers of the western Ross Sea coastline terminate in ice tongues - which are particularly sensitive to changes in flow rate and calving. However, these glaciers have not been retreating in the same way as glaciers on the Antarctic Peninsula - for example the recently calved Larsen C ice shelf that was about the size of Delaware. For the study, based at Portland State University and the University of Colorado, Boulder used historic maps and satellite imagery spanning 60 years, from 1955 to 2015. They analyzed the terminating positions of icebergs, ice speed, calving rates, and ice front advance and retreat rates for 34 glaciers. They also analyzed changes in regional ice flow speed from 2008 to 2014. Although each glacier showed advances and retreats, there was no overall pattern over time or with latitude. This implies that the conditions associated with ice tongue stability haven't changed. The researchers did however note that a weak trend of glacier advance may be present in the nothernmost part of the coast, which is consistent with estimates of increased snow accumulation and glacier mass in that region. In their study, the researchers wrote: 'The stability of these glaciers over the past half century contrasts sharply with the rapidly shrinking glaciers of the Antarctic Peninsula and suggests that no significant climate change, as manifest in glacier change, has reached this region of Antarctica.' Earlier studies had documented little change in the western Ross coastline prior to 1995, and this new study both confirms the earlier work and extended the analysis to the present. The researchers say that this work highlights the complexity of Antarctic climate change and glacier response.