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Concept

Lac subglaciaire

Publications associées (25)

The microbial genomics of glacier-fed streams: adaptations to an extreme ecosystem

Massimo Bourquin

Glacier-fed streams are the cold, ultra-oligotrophic, and unstable streams that are fed by glacial meltwater. Despite these extreme conditions, they harbour a diverse and abundant microbial diversity that develops into biofilms, covering the boulders and s ...

EPFL2024

Global emergent responses of stream microbial metabolism to glacier shrinkage

Tom Ian Battin, Hannes Markus Peter, Tyler Joe Kohler, Massimo Bourquin, Michail Styllas, Nicola Deluigi

Most cryospheric ecosystems are energy limited. How their energetics will respond to climate change remains largely unknown. This is particularly true for glacier-fed streams, which interface with the cryosphere and initiate some of Earth's largest river s ...

Nature Portfolio2024

Treeline displacement may affect lake dissolved organic matter processing at high latitudes and altitudes

Hannes Markus Peter

Climate change induced shifts in treeline position, both towards higher altitudes and latitudes induce changes in soil organic matter. Eventually, soil organic matter is transported to alpine and subarctic lakes with yet unknown consequences for dissolved ...

Nature Portfolio2024

Combined Earth observations reveal the sequence of conditions leading to a large algal bloom in Lake Geneva

Damien Bouffard, Abolfazl Irani Rahaghi, Oscar Rodrigo Sepúlveda Steiner, Frédéric Charles Soulignac, Rafael Sebastian Reiss

Freshwater algae exhibit complex dynamics, particularly in meso-oligotrophic lakes with sudden and dramatic increases in algal biomass following long periods of low background concentration. While the fundamental prerequisites for algal blooms, namely ligh ...

Springernature2024

Near-bed stratification controls bottom hypoxia in ice-covered alpine lakes

Damien Bouffard, Hugo Nicolás Ulloa Sánchez, Camille Roland Marie Minaudo, Janine Rüegg, Nicolas Thomas Georges Escoffier, Tomy Doda, Hannah Elisa Chmiel, Pascal Perolo

In ice-covered lakes, near-bottom oxygen concentration decreases for most of the wintertime, sometimes down to the point that bottom waters become hypoxic. Studies insofar have reached divergent conclusions on whether climate change limits or reinforces th ...

American Society of Limnology and Oceanography2023

Blue ice in Antarctica: The gateway to travel in time and space

Devis Tuia, Marc Conrad Russwurm, Benjamin Alexander Kellenberger

Antarctica has unique areas that expose blue ice, which contrast to most of the continent (~98%) that is covered by snow. Some of these blue ice areas (BIAs) contain meteorite concentrations and (very) old ice, making them very valuable for understanding o ...

GFZ German Research Centre for Geosciences2023

Untangling the influence of Antarctic and Southern Ocean life on clouds

Julia Schmale, Hélène Paule Angot, Markus Frey

Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over A ...

2023

Controlling factors of phytoplankton distribution in the river–lake transition zone of a large lake

David Andrew Barry, Frédéric Charles Soulignac

River–lake transition zones have been identified as major drivers of phytoplankton growth. With climate change reducing the frequency of complete lake overturns, it is expected that the Rhône River, the main tributary to Lake Geneva (France/Switzerland), w ...

2023

Southern Hemisphere atmospheric history of carbon monoxide over the late Holocene reconstructed from multiple Antarctic ice archives

Jérôme Chappellaz

Carbon monoxide (CO) is a naturally occurring atmospheric trace gas, a regulated pollutant, and one of the main components determining the oxidative capacity of the atmosphere. Evaluating climate–chemistry models under different conditions than today and c ...

2023

Iron Reduction in Profundal Sediments of Ultraoligotrophic Lake Tahoe under Oxygen-Limited Conditions

Meret Aeppli

Increased periods of bottom water anoxia in deep temperate lakes due to decreasing frequency and depth of water column mixing in a warming climate may result in the reductive dissolution of iron minerals and increased flux of nutrients from the sediment in ...

2023

Chimney‐Like Intense Pelagic Upwelling in the Center of Basin‐Scale Cyclonic Gyres in Large Lake Geneva

David Andrew Barry, Ulrich Lemmin, Rafael Sebastian Reiss, Seyed Mahmood Hamze Ziabari, Mehrshad Foroughan

Basin-scale quasi-geostrophic gyres are common features of large lakes subject to Coriolis force. Cyclonic gyres are often characterized by dome-shaped thermoclines that form due to pelagic upwelling that takes place in their center. At present, the dynami ...

2023

The Biogeochemical Legacy of Arctic Subglacial Sediments Exposed by Glacier Retreat

Tyler Joe Kohler

During past periods of advance, Arctic glaciers and ice sheets overrode soil, sediments, and vegetation and buried significant stores of organic matter (OM); these glaciers are now shrinking rapidly due to climate warming. Little is known about the biogeoc ...

2022

Active lithoautotrophic and methane-oxidizing microbial community in an anoxic, sub-zero, and hypersaline High Arctic spring

Ianina Altshuler

Lost Hammer Spring, located in the High Arctic of Nunavut, Canada, is one of the coldest and saltiest terrestrial springs discovered to date. It perennially discharges anoxic (

2022

LeXPLORE: A floating laboratory on Lake Geneva offering unique lake research opportunities

Alfred Johny Wüest, Damien Bouffard, Natacha Pasche, Sébastien Lavanchy, Sébastien Manuel Lavanchy

Environmental sciences depend heavily on observational data. Successful studies of ecological processes in lakes require in-situ data that cover the relevant temporal scales from milliseconds to entire seasons. Temporal and spatial coverage requirements re ...

2021

Modeling of Stream Metabolism from Reach-scale to the Scale of Entire River Networks

Pier Luigi Segatto

Streams are key components of the global carbon (C) cycle. The river network conceptualization moved from the pipelineâ idea, in which C is solely transported, to the active ecosystemâ concept, in which both terrestrial derived and autochthonous C ...

EPFL2021

Enhanced trace element mobilization by Earth's ice sheets

Tyler Joe Kohler

Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 mu m) concentratio ...

National Academy of Sciences2020

Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers

Tyler Joe Kohler

Meltwater streams connect the glacial cryosphere with downstream ecosystems. Dissolved and particulate matter exported from glacial ecosystems originates from contrasting supraglacial and subglacial environments, and exported microbial cells have the poten ...

Frontiers Media SA2020

Data set of dissolved major and trace elements from the lacustrine systems of Clearwater Mesa, Antarctica

Tyler Joe Kohler

This article presents analytical observations on physicochemical parameters and major and trace element concentrations of water, ice, and sediment samples from the lake systems of Clearwater Mesa (CWM), northeast Antarctic Peninsula. Geo-chemical analyses ...

2020

Density-dependent solute transport in a layered hyporheic zone

David Andrew Barry, Mohsen Cheraghi, Qihao Jiang

Hyporheic exchange is affected by bedform geometry, which induces complex flow paths within the bedform. Additional factors that influence flow and solute transport in the hyporheic zone are layered profile sediments and density-driven flow. This study exp ...

ELSEVIER SCI LTD2020

Carbon turnover and microbial activity in an artificial soil under imposed cyclic drainage and imbibition

Tatjana Milojevic

Water table fluctuations generate temporally and spatially dynamic physicochemical conditions that drive biogeochemical hot spots and hot moments in the vadose zone. However, their role in the cycling of soil C remains poorly known. Here, we present result ...

2020