English
norskInstitutt for geovitenskap
Bla i:
Enhetens samlinger
Nye registreringer
-
Changes in Planktic Foraminiferal Distribution, Productivity, and Preservation in the Barents Sea During the Last Three Millennia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-04-15)Planktic foraminifers are ubiquitous marine calcifiers sensitive to ocean biogeochemical and physical changes. Their fossil remains have thus been widely used for the reconstruction of past oceanographic and climatic changes. Here, we have investigated the distribution patterns of planktic foraminiferal species, their abundance, shell size, and preservation state in two sediment cores from the ... -
Observation-Based Estimate of Net Community Production in Antarctic Sea Ice
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-04-01)Antarctic sea ice is one of the largest biomes on Earth providing a critical habitat for ice algae. Measurements of primary production in Antarctic sea ice remain scarce and an observation‐based estimate of primary production has not been revisited in over 30 years. We fill this knowledge gap by presenting a newly compiled circumpolar data set of particulate and dissolved organic carbon from 362 ... -
Correlating organic carbon burial with regional climate variability: the past two centuries tale from Sermilik fjord, Southeast Greenland
(Conference object; Konferansebidrag, 2025-02-28)As the Arctic undergoes ‘Atlantification’ and warms at a faster rate than lower latitudes, dramatic physical and biological changes are occurring in the ocean, atmosphere and cryosphere systems. This project focusses on fjord environments connected to the Greenland Ice Sheet, which has recently experienced a significant and rapid loss of ice attributed primarily to changes in the surface mass balance ... -
Investigating Carbon, Nutrient and Methane Dynamics in Proglacial Lakes: Study Design and Objectives for the Southwestern Greenland Campaign
(Conference object; Konferansebidrag, 2025-02-28)Methane, a potent greenhouse gas, is increasingly recognized to be emitted from newly deglaciated environments, particularly in the Arctic, yet due to data scarcity these sources remain underrepresented in global methane budgets. Deglaciation leads to the expansion of proglacial terrains, driving the formation of an increasing number of proglacial lakes worldwide, especially in Greenland. Small to ... -
Constraining the Gas Hydrates Stability Zone beneath the Antarctic Ice Sheet from 40 Ma to the year 3000
(Conference object; Konferansebidrag, 2025-02-28)The Antarctic Ice Sheet (AIS) is one of the climate tipping elements on Earth and the largest potential contributor to sea level rise. While the consequences of ice sheet collapse on oceanic and atmospheric changes are well documented, its impact on the global carbon cycle remains critically ignored in the current global carbon budget. This is particularly important because the Antarctic Sedimentary ... -
Diatom distribution and long-term survival in a heavily polluted sediment core from the Bay of Bagnoli (Tyrrhenian Sea, Italy)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-01-18)Diatom resting stages can remain viable in sediments for decades and germinate when exposed to suitable environmental conditions, inoculating the water column and the surface sediments with new populations of cells. Classical methods, based on acid-cleaning of diatom frustules in sediment samples, do not discriminate between living and dead cells and may destroy the more fragile taxa. We used a ... -
Geochemical and mineralogical characteristics of fjord sediments in Arctic Svalbard: insights into Holocene glacial activity and weathering variability
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-18)The Svalbard archipelago at the border of the Arctic Ocean experiences substantial glacier retreat due to global warming, resulting in a retreat of glacier termini from the marine to terrestrial settings. However, the impact of these transitions on marine environments remains poorly understood. To improve our understanding of how Arctic Svalbard responds to fluctuations in climate and glaciers, we ... -
Cold Seeps and Coral Reefs in Northern Norway: Carbon Cycling in Marine Ecosystems With Coexisting Features
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-20)Cold seeps and cold-water corals (CWCs) coexist on Northern Norway's continental shelf at the Hola trough between Lofoten and Vesterålen. Here, cold seeps release methane from the seabed, yet none reaches the sea surface. Instead, the methane dissolves and disperses in the ocean where it is ultimately consumed by methane-oxidizing microorganisms. These microorganisms metabolize methane and release ... -
Miocene ice sheet dynamics and sediment deposition in the central Ross Sea, Antarctica
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-09)Drill cores from the Antarctic continental shelf are essential for directly constraining changes in past Antarctic Ice Sheet extent. Here, we provide a sedimentary facies analysis of drill cores from International Ocean Discovery Program (IODP) Site U1521 in the Ross Sea, which reveals a unique, detailed snapshot of Antarctic Ice Sheet evolution between ca. 18 Ma and 13 Ma. We identify distinct ... -
Grain-scale feedback between deformation mechanisms and metamorphic reactions: Dissolution-precipitation processes in the lower crust (Kågen gabbros)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-02)Strain localization within crustal shear zones involves intricate feedback between deformation mechanisms, metamorphic reactions and fluid circulation. Despite evidence that these high-deformation zones proceed at least partly through dissolution-precipitation creep, available creep laws so far only account for dislocation creep and/ or solid-state diffusion processes. Deciphering the role and ... -
Snow Mass Recharge of the Greenland Ice Sheet Fueled by Intense Atmospheric River
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-03)Atmospheric rivers (ARs) have been linked with extreme rainfall and melt events across the Greenland ice sheet (GrIS), accelerating its mass loss. However, the impact of AR-fueled snowfall has received less attention, partly due to limited empirical evidence. Here, we relate new firn core stratigraphy and isotopic analyses with glacio-meteorological data sets from SE Greenland to examine an intense ... -
Deep learning-based characterization of underwater methane bubbles using simple dual camera platform
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-10)Seabed gas and oil emissions appear as bubble plumes ascending through the water column in various environments. Understanding bubble characteristics—size, rise speed—is important for estimating escape rates of fluids like methane, oil, and carbon dioxide. However, measuring underwater gas bubbles is challenging, often requiring expensive specialized equipment. This study presents a novel methodology ... -
Lithology as a factor for the distribution of metals in stream sediments associated with sediment-hosted Cu deposits: a case study from the Alta-Kvænangen tectonic window, northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-04)The Kåfjord area in northern Norway hosts numerous Cu deposits that were subjected to mining activities back in the nineteenth century. Relicts of the historical mining activity are still visible at several abandoned mines and associated mine waste disposal sites that may represent an environmental threat. The area was subjected to mining activities during the nineteenth century and abandoned mines ... -
3D seismic investigation of fluid migration and fluid accumulation related to natural seeps in the Sørvestsnaget Basin, SW Barents Sea
(Mastergradsoppgave; Master thesis, 2025-01-27)This master thesis examines the intricacies of fluid migration, gas seep areas, and fault dynamics in the southwestern Barents Sea. Acoustic evidence, such as pockmarks and gas flares, indicates active fluid movement within the below seabed sedimentary structures, such as clinoforms and the Upper Regional Unconformity (URU). Challenging lowermost reaches of gas chimneys, obscured by acoustic masking, ... -
New xenophyophores (Foraminifera, Monothalamea) from the eastern Clarion-Clipperton Zone (equatorial Pacific)
(Journal article; Tidsskriftartikkel, 2024-03-06)Xenophyophores are large, agglutinated foraminifera that dominate the benthic megafauna in some parts of the deep sea. Here, we describe an assemblage of largely fragmentary specimens from the Clarion-Clipperton Zone (CCZ), an area of the eastern abyssal Pacific hosting large, commercially significant deposits of polymetallic nodules. We recognised 18 morphospecies of which eight yielded DNA sequences. ... -
Cultural activity and impact of extreme weather events revealed by ambient seismic noise and perspective on quick clay failure monitoring in Oslo, Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-01)The study of urban seismic noise offers various approaches to monitor cities, from source identification to structural investigations. We demonstrate its potential to monitor cultural activity and quick clay failure in Oslo, Norway using low-cost seismic sensors. We identify train passages, a rock concert, construction blasts, local earthquakes and a meteor. To retrieve seismic velocity variations ... -
Importance of grain boundary processes for plasticity in the quartz-dominated crust: Implications for flow laws
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-01)When H<sub>2</sub>O is present along grain boundaries, the deformation processes responsible for plasticity in silicate mineral aggregates can deviate from what may be conventionally expected. Although a necessary component of understanding crustal deformation processes, there is no theoretical framework that incorporates grain boundary processes into polycrystalline quartz rheology. To address this ... -
Shifts in Greenland interannual climate variability lead Dansgaard–Oeschger abrupt warming by hundreds of years
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-24)During the Last Glacial Period (LGP), Greenland experienced approximately 30 abrupt warming phases, known as Dansgaard–Oeschger (D–O) events, followed by cooling back to baseline glacial conditions. Studies of mean climate change across warming transitions reveal indistinguishable phase offsets between shifts in temperature, dust, sea salt, accumulation, and moisture source, thus preventing a ... -
Lower Cretaceous holostratigraphy in Svalbard: the Arctic key piece of the Boreal basin puzzle
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-25)Lower Cretaceous stratigraphy of the high palaeo-latitude Arctic-Boreal Realm is generally more poorly understood than its lower-latitude Tethyan counterpart, prohibiting regional correlations and evaluation of global climate dynamics during this important high-pCO2 period. In this paper, a holostratigraphic scheme and lithostratigraphic revision are presented for the Valanginian–lower Barremian, ... -
Hydroclimate intensification likely aided glacier survival on Svalbard in the Early Holocene
(Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-11)Accelerated Arctic warming and wetting has global impacts, as the region’s glaciers and ice caps respond to variations in temperature and precipitation, impacting global sea-level change. But as the observations needed to calibrate models are scarce, predictions cannot confirm if increases in snowfall can help offset melt. Here, we analyze two 14,000-year-long glacier-fed lake sediment records ...
RSS 1.0