English
norskBlar i forfatter "Bjarnadóttir, Lilja Rún"
Viser treff 1-10 av 10
-
Advances in understanding subglacial meltwater drainage from past ice sheets
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-17)Meltwater drainage beneath ice sheets is a fundamental consideration for understanding ice–bed conditions and bed-modulated ice flow, with potential impacts on terminus behavior and iceshelf mass balance. While contemporary observations reveal the presence of basal water movement in the subglacial environment and inferred styles of drainage, the geological record of former ice sheets, including ... -
Arctic Ocean glacial history
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-11-14)While there are numerous hypotheses concerning glacial–interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the ... -
Deglaciation of the central Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05-15)The marine-based Barents Sea Ice Sheet covered the polar continental shelf north of Norway and western Russia during the Last Glacial Maximum. Initial ice sheet retreat along the western margin is well established, while the retreat pattern in the interior parts of the ice sheet remains poorly known. Here we present new geological data from the central Barents Sea. The results are based on analysis ... -
Exceptions to bed-controlled ice sheet flow and retreat from glaciated continental margins worldwide
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-13)Projections of ice sheet behavior hinge on how ice flow velocity evolves and the extent to which marine-based grounding lines are stable. Ice flow and grounding line retreat are variably governed by the coupling between the ice and underlying terrain. We ask to what degree catchment-scale bed characteristics determine ice flow and retreat, drawing on paleo-ice sheet landform imprints from 99 sites ... -
Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a palaeobenchmark for models of marine icesheet deglaciation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-14)Our understanding of processes relating to the retreat of marine-based ice sheets, such as the West Antarctic Ice Sheet and tidewater-terminating glaciers in Greenland today, is still limited. In particular, the role of ice-stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, ... -
Ice‐margin retreat and grounding‐zone dynamics during initial deglaciation of the Storfjordrenna Ice Stream, western Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-11)Processes occurring at the grounding zone of marine terminating ice streams are crucial to marginal stability, influencing ice discharge over the grounding‐line, and thereby regulating ice‐sheet mass balance. We present new marine geophysical data sets over a ~30×40 km area from a former ice‐stream grounding zone in Storfjordrenna, a large cross‐shelf trough in the western Barents Sea, south of ... -
Large subglacial meltwater features in the central Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-01)During the last glacial period large parts of the Arctic, including the Barents Sea, north of Norway and Russia, were covered by ice sheets. Despite several studies indicating that melting occurred beneath much of the Barents Sea ice sheet, very few meltwater-related landforms have been identified. We document ∼200 seafloor valleys in the central Barents Sea and interpret them to be tunnel valleys ... -
New cold seep sites on the continental slope southwest to Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-09)We discovered seafloor features such as bacterial mats and carbonate crusts typical for active methane seeps on the continental slope southwest of Svalbard. These features are associated with two main northwest-southeast trending morphological structures that are oriented parallel to the regional continental slope. Both structures occur at c. 800 m water depth, at the boundary between the Storfjorden ... -
Retreat patterns and dynamics of the Sentralbankrenna glacial system, central Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-26)The Barents Sea Ice Sheet (BSIS) is a good palaeo-analogue for the present day West Antarctic Ice Sheet. Both were marine-based ice sheets, particularly vulnerable to ocean warming and sea-level rise. Understanding the BSIS ice dynamics and patterns of retreat since the Last Glacial Maximum (LGM) is useful in developing our knowledge of spatial and temporal variations during marine-based ice sheet ... -
A time-transgressive perspective of glacial erosion and meltwater beneath the Eurasian ice sheet
(Conference object; Konferansebidrag, 2023-08)The efficacy and controls governing glacial erosion over geological timescales are intricately linked yet remain poorly understood and contended. By assimilating geophysical data with modelling of the Eurasian Ice Sheet - the third largest Quaternary ice mass that spanned 49°N - 82°N - we decipher its erosional footprint during the last ~110 ka glacial cycle. Our results demonstrate extreme ...
