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| Open AccessElevational differences in hydrogeomorphic disturbance regime influence sediment residence times within mountain river corridors
Extreme climatic events and wildfires can potentially influence sediment residence times in rivers, although the effect is not clear. Here, the authors present radiocarbon ages to show mountain streams as stable retentive reservoirs poised to change under shifting hydrologic and fire regimes.
- Nicholas A. Sutfin
- & Ellen Wohl
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| Open AccessSurface melt driven summer diurnal and winter multi-day stick-slip motion and till sedimentology
Glacier meltwater can penetrate the glacier bed and act as a lubricant, accelerating retreat. Here, the authors use the unique Glacsweb wireless probe at Skálafellsjökull in Iceland and find evidence for two types of stick-slip events: small diurnal events in summer and large multiday events in winter.
- Jane K. Hart
- , Kirk Martinez
- & David S. Young
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| Open AccessSignificant contribution of subseafloor microparticles to the global manganese budget
Ferromanganese minerals are abundant in marine environments but the extent of these minerals in subseafloor sediments remains unknown. Here the authors find abundant ferromanganese microparticles in oxic pelagic clays, accounting for 14–16% of the new estimate of the global manganese budget (9.2–47.4 Tt).
- Go-Ichiro Uramoto
- , Yuki Morono
- & Fumio Inagaki
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Article
| Open AccessVegetation response to exceptional global warmth during Oceanic Anoxic Event 2
The Cretaceous Oceanic Anoxic Event 2 represents one of the warmest episodes in the last 250 million years. Here, the authors present spore-pollen data and temperature estimates (TEX86) across an expanded stratigraphic section illustrating the dynamic response of vegetation during this exceptionally warm interval.
- Ulrich Heimhofer
- , Nina Wucherpfennig
- & Ariane Kujau
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Article
| Open AccessGlacigenic sedimentation pulses triggered post-glacial gas hydrate dissociation
Triggers of gas hydrate instability along continental margins remain debated. Here, via numerical simulations, the authors show that pulses in sedimentation, rather than bottom water temperature or sea level change, likely triggered gas hydrate dissociation offshore Norway at the end of the last glaciation.
- Jens Karstens
- , Haflidi Haflidason
- & Jürgen Mienert
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| Open AccessTectonically-triggered sediment and carbon export to the Hadal zone
Within sediments in deep ocean trenches an earthquake record may be observed. Here, the authors present 14C data on bulk organic carbon (OC) and thermal decomposition from a sediment core in the Japan Trench and match OC values with known earthquake events.
- Rui Bao
- , Michael Strasser
- & Timothy I. Eglinton
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Article
| Open AccessFreshwater lake to salt-water sea causing widespread hydrate dissociation in the Black Sea
Gas hydrates are maintained via a balance of temperature and pressure, if this changes then destabilization may occur. Here, the authors show instead that due to recent changes in the salinity of the sea water of the Black Sea, gas hydrates may become destabilized with widespread methane seepage.
- Vincent Riboulot
- , Stephan Ker
- & Gabriel Ion
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Article
| Open AccessProdigious submarine landslides during the inception and early growth of volcanic islands
As volcanic islands grow via subaerial shield-building and edifice growth, large submarine landslides occur. Here, the authors reconstruct the emergence of the Canary Islands via turbidites created by submarine landslides as the islands grew, showing that slides are multi-stage.
- James E. Hunt
- & Ian Jarvis
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Article
| Open AccessCounter-intuitive influence of Himalayan river morphodynamics on Indus Civilisation urban settlements
The Bronze-age Indus civilisation (4.6–3.9 ka) was thought to have been linked to the development of water resources in the Himalayas. Here, the authors show that along the former course of the Sutlej River the Indus settlements developed along the abandoned river valley rather than an active Himalayan river.
- Ajit Singh
- , Kristina J. Thomsen
- & Sanjeev Gupta
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Article
| Open AccessMarine oxygen production and open water supported an active nitrogen cycle during the Marinoan Snowball Earth
Snowball Earth glaciations were some of the most extreme climate events in Earth history, and are temporally linked to major biogeochemical changes. Here, using geochemical proxies, the authors show that during the Marinoan glaciation, there was likely open water, active oxygen production, and nitrogen cycling.
- Benjamin W. Johnson
- , Simon W. Poulton
- & Colin Goldblatt
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| Open AccessTidal dynamics and mangrove carbon sequestration during the Oligo–Miocene in the South China Sea
Mangroves are important carbon-rich biomes, but their long-term impact on the global carbon cycle is relatively unknown. Here, the authors show that the Oligo–Miocene mangroves in the South China Sea stored in excess of 4,000 Gt, demonstrating the long-term impact of mangroves on carbon storage.
- Daniel S. Collins
- , Alexandros Avdis
- & Abdul Razak Damit
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Article
| Open AccessEvidence for a palaeo-subglacial lake on the Antarctic continental shelf
While a number of subglacial lakes have been discovered beneath the modern Antarctic ice sheet, little is known regarding their prevalence during past glaciations. Here, Kuhnet al. present sedimentological evidence for an active palaeo-subglacial lake in Pine Island Bay during the last glaciation.
- Gerhard Kuhn
- , Claus-Dieter Hillenbrand
- & José M. Mogollón
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| Open AccessMorphometric convergence between Proterozoic and post-vegetation rivers
It has been previously assumed that deep river channels could not have developed in the Proterozoic due to lack of vegetation. Here, the authors present remote sensing and outcrop data to show that large scale and deeply channelled river networks did exist in the Proterozoic despite the absence of vegetation.
- Alessandro Ielpi
- , Robert H. Rainbird
- & Massimiliano Ghinassi
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| Open AccessExplosive eruption, flank collapse and megatsunami at Tenerife ca. 170 ka
Oceanic shield volcanoes flank failures can generate large tsunamis. Here, the authors provide evidence that two tsunamis impacted the coast of Tenerife 170 Ma, the first generated by volcano flank failure and the second following a debris avalanche of the edifice during an on-going ignimbrite-forming eruption.
- Raphaël Paris
- , Juan J. Coello Bravo
- & François Nauret
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| Open AccessTwo-stage opening of the Dover Strait and the origin of island Britain
Britain’s separation from mainland Europe is believed to be the result of spillover from a proglacial lake in the North Sea, but this has remained unproven. Here, the authors show that the opening of the Dover Strait occurred in two episodes, where initial lake spillover was followed by catastrophic flooding.
- Sanjeev Gupta
- , Jenny S. Collier
- & John C. R. Arthur
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| Open AccessResilience of the Asian atmospheric circulation shown by Paleogene dust provenance
The onset of modern central Asian atmospheric circulation is often linked to the interplay of late Cenozoic paleogeographic changes and global cooling. Here the authors present sedimentary provenance data from early Cenozoic dust deposits, which indicate long-term stability of the central Asian high pressure system.
- A. Licht
- , G. Dupont-Nivet
- & D. Giesler
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Article
| Open AccessMicrobially assisted recording of the Earth’s magnetic field in sediment
Sediments record variations of the Earth’s magnetic field via the alignment of magnetic grains during and after deposition, yet the role of post-depositional processes remains unclear. Here, the authors present experiments showing how microbially-induced bioturbation controls the alignment process.
- Xiangyu Zhao
- , Ramon Egli
- & Sebastian Müller
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| Open AccessAfrican humid periods triggered the reactivation of a large river system in Western Sahara
Given the absence of a major river system in the Western Sahara, the source of late Quaternary fluvial sediments along the West African margin remains unclear. Here, the authors present geomorphological data that reveal the existence of a large buried paleodrainage network on the Mauritanian coast.
- C. Skonieczny
- , P. Paillou
- & F. Grousset
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| Open AccessLoess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment
Theories of Cenozoic mountain uplift and associated global cooling assume that eroded mountain sediments are stored in marine basins. Here, based on detailed provenance data, Nie et al. show that Northeast Tibetan sediments are in fact stored inland, in the Chinese Loess Plateau and Mu Us desert.
- Junsheng Nie
- , Thomas Stevens
- & Baotian Pan
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Late glacial initiation of Holocene eastern Mediterranean sapropel formation
Numerous theories exist regarding the evolution of a deep-water oxygen deficiency in the eastern Mediterranean Sea. Here, the authors test several popular hypotheses with a focus on the S1 event showing that long-term stagnation was necessary, preconditioned by the changes associated with the last deglaciation.
- Rosina Grimm
- , Ernst Maier-Reimer
- & Kay-Christian Emeis
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Micro-trace fossils reveal pervasive reworking of Pliocene sapropels by low-oxygen-adapted benthic meiofauna
Meiofaunal burrowing is thought to produce sediment textures that appear devoid of animal activity, thus the record of meiofaunal activity remains unknown. Here, the authors apply a novel sampling and electron imaging approach to identify meiofaunal traces in Pliocene sapropels, a classic anoxic facies.
- S.C. Löhr
- & M.J. Kennedy
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| Open AccessThe pervasive role of biological cohesion in bedform development
The role of cohesion is vital to our understanding of how sedimentary bedforms evolve. Here, the authors show that microorganisms within the sediment affect cohesion and demonstrate that ripples can take up to one hundred times as long to develop when extracellular polymeric substances are present.
- Jonathan Malarkey
- , Jaco H. Baas
- & Peter D. Thorne
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| Open AccessEruption of a deep-sea mud volcano triggers rapid sediment movement
Submarine mud volcanoes are difficult to observe from the sea surface and previous recordings at depth have been short term. Here, the authors provide the first long-term monitoring from Håkon Mosby and suggest that mud volcanoes may be more important to the global methane budget than previously thought.
- Tomas Feseker
- , Antje Boetius
- & Dirk de Beer
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Differentiated availability of geochemical mercury pools controls methylmercury levels in estuarine sediment and biota
Methylmercury in aquatic biota constitutes a severe environmental issue globally, but models struggle to provide accurate quantification. Here, the authors combine experimental approaches to assess contributions from different pools and use the data to interpret the mercury cycle in an estuarine setting.
- Sofi Jonsson
- , Ulf Skyllberg
- & Erik Björn
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Quantitative bounds on morphodynamics and implications for reading the sedimentary record
Sedimentary rocks record planetary environmental history convolved with the internal dynamics of depositional landscapes. Ganti et al.show that the advection length of settling sediment sets bounds on internal landscape dynamics, providing a new tool to unravel sedimentary archives.
- Vamsi Ganti
- , Michael P. Lamb
- & Brandon McElroy
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Long livestock farming history and human landscape shaping revealed by lake sediment DNA
Humans have influenced the shaping of the landscape for generations, yet disentangling these influences from those of climate is a challenge. Giguet-Covex et al.take the novel approach of using lake sediment DNA to reconstruct a detailed picture of human land use since the Neolithic Period.
- Charline Giguet-Covex
- , Johan Pansu
- & Pierre Taberlet