Grounding‐line dynamics during the last deglaciation of Kveithola, W Barents Sea, as revealed by seabed geomorphology and shallow seismic stratigraphy

• Published in: Boreas
• Main Authors: Bjarnadóttir, Lilja R., Rüther, Denise C., Winsborrow, Monica C. M., Andreassen, Karin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Barents Sea
• Online Access: http://dx.doi.org/10.1111/j.1502-3885.2012.00273.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2012.00273.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2012.00273.x

A marine geophysical study reveals a complex deglaciation pattern in the K veithola trough, W B arents S ea. The data set includes multibeam swath bathymetry and sub‐bottom sediment profiler (chirp) data acquired for the whole extent of a palaeo, marine‐terminating ice stream, along with high‐resolution single‐channel seismic data from chosen profiles. The multibeam data show a geomorphic landform assemblage characteristic of ice streams. The results of a combination of seismic and chirp unit stratigraphy reveal that the seabed geomorphology is governed by a deeper‐lying reflector. The reflector dominates surface expressions of several subglacial and ice‐marginal units, each connected to a separate episode of ice‐margin stillstand/advance. Analysis of the combined data set has resulted in a conceptual model of the ice‐stream retreat. The model depicts complex deglaciation of a small, confined ice‐stream system through episodic retreat. It describes the formation of several generations of grounding‐zone systems, characterized by high meltwater discharges and the deposition of fine‐grained grounding‐line fans. The inferred style of grounding‐zone deposition in K veithola deviates from that of other accounts, and is suggested to be intermediate in the previously described continuum between morainal banks and grounding‐line wedges. The results of this paper have implications for grounding‐zone theory and should be of interest to modellers of grounding‐line dynamics and ice‐stream retreat.