Greenland’s ice sheet was larger than expected Published 05.09.2024

Takussutissiaq 1. Immap assingani umiarsuarmit RV Tarajoq-mik ingerlaarfiit (qalipaatit erseqqarissut) immap naqqata ilusaa (qalipaatinik assigiinngitsunik immikkoortitigaq). Immap naqqani qaleriiaarnerit narsaamanerillu (qernertut) sermersuup ataani ilusilerneqarsimasuupput, immap naqqani qaleriiaarnerit (qaqortut) nunatta sermersuanit ilusilersorneqarsimasuupput, sermersuup annertunerpaaffiata nalaani taamatut ilusilerneqarsimagamik. Titarnerit nunatta qaarsuata killeqarfii immap naqqani innaannarsuaqarfiupput. Ilisimatuussutsikkut allaaserisami sukumiinerusumik samminnittoqarpoq.
Takussutissiaq 2. Baffin Bugtip avannaatungaani sermersuaqarnerpaaffiata nalaani sermip ataani sullorujussuup inikui ersipput. Aappaluttumik qalipaaserneqarsimasut sermip ataani sullorsuaasimasoq killeqarfigisimavai, tikkuussisullu tungujortumik qalipaatillit sermip qanoq ingerlaartarsimanerinik ersersitsipput. Paasissutissat annertunerit saqqummersitamiipput.

Researchers from Newcastle University and Greenland Institute of Natural Resources have discovered new details about the ancient ice sheets that once covered Greenland. This is crucial in understanding how these ice masses behaved during the Last Glacial Maximum, roughly 26,500 to 19,000 years ago. By analyzing newly acquired high-resolution geophysical data from the seafloor off northwest Greenland, scientists have mapped glacial landforms that challenge previous assumptions (Figure 1).

The data reveal that the Greenland Ice Sheet extended all the way to the shelf break along the entire northwest Greenland margin, much farther than previously thought. The data also suggest the presence of a vast ice shelf in northern Baffin Bay, which was fed by ice streams from the Canadian Arctic Archipelago (Figure 2). The study also found that this ice shelf was over 1,100 meters thick at its grounding zone, where it met the ocean floor.

The presence of this extensive ice shelf likely played a critical role in stabilizing the Greenland Ice Sheet during the Last Glacial Maximum by holding back the flow of large ice streams that flowed into Baffin Bay (Figure 2). As this ice shelf broke apart, it may have triggered the rapid retreat of the ice sheets that we see evidence of today. These findings are important for understanding how ice sheets respond to climate changes and will help improve models that predict future ice-sheet behavior and sea-level rise.

In addition to offering new perspectives on the extent of ancient ice coverage, the study also uncovered unusual features on the seafloor, such as deep channels carved by meltwater (Figure 1) and evidence of a short-lived ice stream. These discoveries provide a more detailed picture of how the ice sheets evolved over time, contributing valuable knowledge to the debate on climate change.

 

Paper link here: Shelf-break glaciation and an extensive ice shelf beyond northwest Greenland at the Last Glacial Maximum – ScienceDirect