scholarly journals Microbiology: lessons from a first attempt at Lake Ellsworth

2016 ◽  
Vol 374 (2059) ◽  
pp. 20140291 ◽  
Author(s):  
D. A. Pearce ◽  
I. Magiopoulos ◽  
M. Mowlem ◽  
M. Tranter ◽  
G. Holt ◽  
...  
Keyword(s):  
Local Environment ◽  
Hot Water ◽  
Critical Question ◽  
Ongoing Research ◽  
Subglacial Lake ◽  
Scientific Instrumentation ◽  
Signy Island ◽  
The Antarctic ◽  
Microbiological Analyses

During the attempt to directly access, measure and sample Subglacial Lake Ellsworth in 2012–2013, we conducted microbiological analyses of the drilling equipment, scientific instrumentation, field camp and natural surroundings. From these studies, a number of lessons can be learned about the cleanliness of deep Antarctic subglacial lake access leading to, in particular, knowledge of the limitations of some of the most basic relevant microbiological principles. Here, we focus on five of the core challenges faced and describe how cleanliness and sterilization were implemented in the field. In the light of our field experiences, we consider how effective these actions were, and what can be learnt for future subglacial exploration missions. The five areas covered are: (i) field camp environment and activities, (ii) the engineering processes surrounding the hot water drilling, (iii) sample handling, including recovery, stability and preservation, (iv) clean access methodologies and removal of sample material, and (v) the biodiversity and distribution of bacteria around the Antarctic. Comparisons are made between the microbiology of the Lake Ellsworth field site and other Antarctic systems, including the lakes on Signy Island, and on the Antarctic Peninsula at Lake Hodgson. Ongoing research to better define and characterize the behaviour of natural and introduced microbial populations in response to deep-ice drilling is also discussed. We recommend that future access programmes: (i) assess each specific local environment in enhanced detail due to the potential for local contamination, (ii) consider the sterility of the access in more detail, specifically focusing on single cell colonization and the introduction of new species through contamination of pre-existing microbial communities, (iii) consider experimental bias in methodological approaches, (iv) undertake in situ biodiversity detection to mitigate risk of non-sample return and post-sample contamination, and (v) address the critical question of how important these microbes are in the functioning of Antarctic ecosystems.

The effectiveness of Virkon® S disinfectant against an invasive insect and implications for Antarctic biosecurity practices

2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jesamine C. Bartlett ◽  
Richard James Radcliffe ◽  
Pete Convey ◽  
Kevin A. Hughes ◽  
Scott A.L. Hayward
Keyword(s):  
Salt Water ◽  
Hot Water ◽  
Antarctic Region ◽  
Invasive Insect ◽  
Signy Island ◽  
Antarctic Treaty ◽  
Biosecurity Practices ◽  
Water Treatments ◽  
The Antarctic ◽  
Maximum Threshold

Abstract The flightless midge Eretmoptera murphyi is thought to be continuing its invasion of Signy Island via the treads of personnel boots. Current boot-wash biosecurity protocols in the Antarctic region rely on microbial biocides, primarily Virkon® S. As pesticides have limited approval for use in the Antarctic Treaty area, we investigated the efficacy of Virkon® S in controlling the spread of E. murphyi using boot-wash simulations and maximum threshold exposures. We found that E. murphyi tolerates over 8 h of submergence in 1% Virkon® S. Higher concentrations increased effectiveness, but larvae still exhibited > 50% survival after 5 h in 10% Virkon® S. Salt and hot water treatments (without Virkon® S) were explored as possible alternatives. Salt water proved ineffective, with mortality only in first-instar larvae across multi-day exposures. Larvae experienced 100% mortality when exposed for 10 s to 50°C water, but they showed complete survival at 45°C. Given that current boot-wash protocols alone are an ineffective control of this invasive insect, we advocate hot water (> 50°C) to remove soil, followed by Virkon® S as a microbial biocide on ‘clean’ boots. Implications for the spread of invasive invertebrates as a result of increased human activity in the Antarctic region are discussed.

scholarly journals Clean subglacial access: prospects for future deep hot-water drilling

2016 ◽  
Vol 374 (2059) ◽  
pp. 20140304 ◽  
Author(s):  
Keith Makinson ◽  
David Pearce ◽  
Dominic A. Hodgson ◽  
Michael J. Bentley ◽  
Andrew M. Smith ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Field Testing ◽  
Lessons Learned ◽  
Hot Water ◽  
Water Recovery ◽  
Subglacial Lake ◽  
Comprehensive Plan ◽  
Recovery System ◽  
Hydrological System ◽  
The Antarctic

Accessing and sampling subglacial environments deep beneath the Antarctic Ice Sheet presents several challenges to existing drilling technologies. With over half of the ice sheet believed to be resting on a wet bed, drilling down to this environment must conform to international agreements on environmental stewardship and protection, making clean hot-water drilling the most viable option. Such a drill, and its water recovery system, must be capable of accessing significantly greater ice depths than previous hot-water drills, and remain fully operational after connecting with the basal hydrological system. The Subglacial Lake Ellsworth (SLE) project developed a comprehensive plan for deep (greater than 3000 m) subglacial lake research, involving the design and development of a clean deep-ice hot-water drill. However, during fieldwork in December 2012 drilling was halted after a succession of equipment issues culminated in a failure to link with a subsurface cavity and abandonment of the access holes. The lessons learned from this experience are presented here. Combining knowledge gained from these lessons with experience from other hot-water drilling programmes, and recent field testing, we describe the most viable technical options and operational procedures for future clean entry into SLE and other deep subglacial access targets.

scholarly journals Developing a hot-water drill system for the WISSARD project: 2. In situ water production

2014 ◽  
Vol 55 (68) ◽  
pp. 298-302 ◽  
Author(s):  
Daren S. Blythe ◽  
Dennis V. Duling ◽  
Dar E. Gibson
Keyword(s):  
Waste Heat ◽  
Hot Water ◽  
Water Production ◽  
Initial Water ◽  
Diameter Hole ◽  
Water Heaters ◽  
Whillans Ice Stream ◽  
The Antarctic ◽  
Drill System

AbstractSuccessful hot-water drilling in the Antarctic is predicated on utilization of the abundant water supply available in the form of the Antarctic ice sheet. For WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) field operations, a snowmelting system was developed that could adequately provide water for a 1000 kW hot-water drill. The system employs ∼100 kW of waste heat from a 225 kW generator to melt snow for initial water (known as seed water) to prime the drill’s high-pressure pumps and water heaters; once the water heaters can be engaged in snowmelting, enough water can be supplied directly to the WISSARD drill to successfully melt a 40 cm diameter hole through 800 m of ice.

scholarly journals Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ulrike Braeckman ◽  
Francesca Pasotti ◽  
Ralf Hoffmann ◽  
Susana Vázquez ◽  
Angela Wulff ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Benthic Communities ◽  
Benthic Primary Production ◽  
Community Metabolism ◽  
West Antarctic ◽  
Run Off ◽  
Net Heterotrophy ◽  
Benthic Ecosystems ◽  
The Antarctic

AbstractClimate change-induced glacial melt affects benthic ecosystems along the West Antarctic Peninsula, but current understanding of the effects on benthic primary production and respiration is limited. Here we demonstrate with a series of in situ community metabolism measurements that climate-related glacial melt disturbance shifts benthic communities from net autotrophy to heterotrophy. With little glacial melt disturbance (during cold El Niño spring 2015), clear waters enabled high benthic microalgal production, resulting in net autotrophic benthic communities. In contrast, water column turbidity caused by increased glacial melt run-off (summer 2015 and warm La Niña spring 2016) limited benthic microalgal production and turned the benthic communities net heterotrophic. Ongoing accelerations in glacial melt and run-off may steer shallow Antarctic seafloor ecosystems towards net heterotrophy, altering the metabolic balance of benthic communities and potentially impacting the carbon balance and food webs at the Antarctic seafloor.

scholarly journals Subglacial Lake CECs: Discovery and in situ survey of a privileged research site in West Antarctica

2015 ◽  
Vol 42 (10) ◽  
pp. 3944-3953 ◽  
Author(s):  
Andrés Rivera ◽  
José Uribe ◽  
Rodrigo Zamora ◽  
Jonathan Oberreuter
Keyword(s):  
West Antarctica ◽  
Subglacial Lake ◽  
Research Site

scholarly journals Nuclear Magnetic Resonance Spectroscopy for In Situ Monitoring of Porous Materials Formation under Hydrothermal Conditions

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1416 ◽  
Author(s):  
Mohamed Haouas
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Porous Materials ◽  
Local Environment ◽  
In Situ Monitoring ◽  
Resonance Spectroscopy ◽  
Hydrothermal Conditions ◽  
Technological Advances ◽  
Nuclear Magnetic

The employment of nuclear magnetic resonance (NMR) spectroscopy for studying crystalline porous materials formation is reviewed in the context of the development of in situ methodologies for the observation of the real synthesis medium, with the aim of unraveling the nucleation and growth processes mechanism. Both liquid and solid state NMR techniques are considered to probe the local environment at molecular level of the precursor species either soluble in the liquid phase or present in the reactive gel. Because the mass transport between the liquid and solid components of the heterogeneous system plays a key role in the synthesis course, the two methods provide unique insights and are complementary. Recent technological advances for hydrothermal conditions NMR are detailed and their applications to zeolite and related materials crystallization are illustrated. Achievements in the field are exemplified with some representative studies of relevance to zeolites, aluminophosphate zeotypes, and metal-organic frameworks.

scholarly journals A quasi-Lagrangian coordinate system based on high resolution tracer observations: implementation for the Antarctic polar vortex

2008 ◽  
Vol 8 (4) ◽  
pp. 16123-16173 ◽  
Author(s):  
E. V. Ivanova ◽  
C. M. Volk ◽  
O. Riediger ◽  
H. Klein ◽  
N. M. Sitnikov ◽  
...  
Keyword(s):  
High Resolution ◽  
Coordinate System ◽  
Vortex Core ◽  
Polar Vortex ◽  
Mixing Ratio ◽  
Lagrangian Coordinate ◽  
Antarctic Polar Vortex ◽  
The Antarctic ◽  
Lagrangian Coordinate System

Abstract. In order to quantitatively analyse the chemical and dynamical evolution of the polar vortex it has proven extremely useful to work with coordinate systems that follow the vortex flow. We propose here a two-dimensional quasi-Lagrangian coordinate system {χi, Δχi}, based on the mixing ratio of a long-lived stratospheric trace gas i, and its systematic use with i = N2O, in order to describe the structure of a well-developed Antarctic polar vortex. In the coordinate system {χi, Δχi} the mixing ratio χi is the vertical coordinate and Δχi = χi(Θ)−χivort(Θ) is the meridional coordinate (χivort(Θ) being a vertical reference profile in the vortex core). The quasi-Lagrangian coordinates {χi, Δχi} persist for much longer time than standard isentropic coordinates, potential temperature Θ and equivalent latitude φe, do not require explicit reference to geographic space, and can be derived directly from high-resolution in situ measurements. They are therefore well-suited for studying the evolution of the Antarctic polar vortex throughout the polar winter with respect to the relevant chemical and microphysical processes. By using the introduced coordinate system {χN2O, ΔχN2O} we analyze the well-developed Antarctic vortex investigated during the APE-GAIA (Airborne Polar Experiment – Geophysica Aircraft in Antarctica – 1999) campaign (Carli et al., 2000). A criterion, which uses the local in-situ measurements of χi=χi(Θ) and attributes the inner vortex edge to a rapid change (δ-step) in the meridional profile of the mixing ratio χi, is developed to determine the (Antarctic) inner vortex edge. In turn, we suggest that the outer vortex edge of a well-developed Antarctic vortex can be attributed to the position of a local minimum of the χH2O gradient in the polar vortex area. For a well-developed Antarctic vortex, the ΔχN2O-parametrization of tracer-tracer relationships allows to distinguish the tracer inter-relationships in the vortex core, vortex boundary region and surf zone and to examine their meridional variation throughout these regions. This is illustrated by analyzing the tracer-tracer relationships χi : χN2O obtained from the in-situ data of the APE-GAIA campaign for i = CFC-11, CFC-12, H-1211 and SF6. A number of solitary anomalous points in the CFC-11 : N2O correlation, observed in the Antarctic vortex core, are interpreted in terms of small-scale cross-isentropic dispersion.

scholarly journals Triassic Wood from the Gordon Valley, Central Transantarctic Mountains, Antarctica

IAWA Journal ◽  
1995 ◽  
Vol 16 (2) ◽  
pp. 111-126 ◽  
Author(s):  
Georgina M. Dei Fueyo ◽  
Edith L. Taylor ◽  
Thomas N. Taylor ◽  
N. Rubén Cúneo
Keyword(s):  
Middle Triassic ◽  
Fossil Wood ◽  
New Taxon ◽  
Axial Parenchyma ◽  
Transantarctic Mountains ◽  
The Antarctic

Wood from an in situ permineralized forest from the Middle Triassic of Gordon Valley (Queen Alexandra Range, central Transantarctic Mountains) in Antarctica is described as a new taxon, Approximately 100 trunks in growth position are present at the site; they range from 13-61 cm in diameter and suggest that some of the trees were up to 20 m tall, Pits in the radial walls of the tracheids are of the abietinean type, Rays are uniseriate and 1-9 cells high; cross fields include one to two pits that appear to be simple, Axial parenchyma is absent. Pith and cortex are not preserved. The Antarctic wood is compared with existing fossil wood types from Antarctica and other parts of Gondwana. Although the fossil wood shares a number of characteristics with the Podocarpaceae, it differs from any existing genera and is described as a new taxon, Jeffersonioxylon gordonense.

scholarly journals Compositional simulation of hydrocarbon recovery from oil shale reservoirs with diverse initial saturations of fluid phases by various thermal processes

2016 ◽  
Vol 35 (2) ◽  
pp. 172-193 ◽  
Author(s):  
Kyung Jae Lee ◽  
George J Moridis ◽  
Christine A Ehlig-Economides
Keyword(s):  
Aqueous Phase ◽  
Single Phase ◽  
Water Injection ◽  
Hot Water ◽  
Electrical Heating ◽  
Hydrocarbon Production ◽  
Well Pattern ◽  
Shale Reservoirs ◽  
Fluid Phases

We have studied the hydrocarbon production from oil shale reservoirs filled with diverse initial saturations of fluid phases by implementing numerical simulations of various thermal in-situ upgrading processes. We use our in-house fully functional, fully implicit, and non-isothermal simulator, which describes the in-situ upgrading processes and hydrocarbon recovery by multiphase-multicomponent systems. We have conducted two sets of simulation cases—five-spot well pattern problems and Shell In-situ Conversion Process (ICP) problems. In the five-spot well pattern problems, we have analyzed the effects of initial fluid phase that fills the single-phase reservoir and thermal processes by four cases—electrical heating in the single-phase-aqueous reservoir, electrical heating in the single-phase-gaseous reservoir, hot water injection in the single-phase-aqueous reservoir, and hot CO2 injection in the single-phase-gaseous reservoir. In the ICP problems, we have analyzed the effects of initial saturations of fluid phases that fill two-phase-aqueous-and-gaseous reservoir by three cases—initial aqueous phase saturations of 0.16, 0.44, and 0.72. Through the simulation cases, system response and production behavior including temperature profile, kerogen fraction profile, evolution of effective porosity and absolute permeability, phase production, and product selectivity are analyzed. In the five-spot well pattern problems, it is found that the hot water injection in the aqueous phase reservoir shows the highest total hydrocarbon production, but also shows the highest water-oil-mass-ratio. Productions of phases and components show very different behavior in the cases of electrical heating in the aqueous phase reservoir and the gaseous phase reservoir. In the ICP problems, it is found that the speed of kerogen decomposition is almost identical in the cases, but the production behavior of phases and components is very different. It is found that more liquid organic phase has been produced in the case with the higher initial saturation of aqueous phase by the less production of gaseous phase.

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