Development of a multibottle gas‐tight fluid sampler WHATS II for Japanese submersibles/ROVs

This paper summarizes the design and performance of our recently developed gas‐tight fluid sampler WHATS II, especially designed to collect seafloor venting gas‐rich fluid from submersibles/remotely operated vehicles (ROVs). It consists of four 150‐cm³ stainless steel sample cylinders, eight ball valves, a motor‐driven arm, a rail, a peristaltic pump, a control unit, and a flexible Teflon tube connected to a titanium inlet tube. All the parts have been designed to be used at undersea as deep as 4000 m. The motor‐driven arm on the rail can open and close each of the four cylinders. By pumping out distilled water that has filled an open cylinder and the dead spaces of the sampler, we can fill the cylinder with sample fluid. WHATS II can take a maximum of four different gas‐tight samples in a series. The whole operation can be arranged from the cabin, etc., of a submersible/ROV. Use of only one motor to operate eight valves makes the sampler small, light (21 kg in sea water), and easy to handle. In addition, the sampler is able to collect an almost uncontaminated gas‐tight sample from the seafloor. To date, the sampler has been used in more than 90 dive surveys by Japanese submersibles/ROVs, including Shinkai 2000, Shinkai 6500, and Hyper Dolphin, with a success rate of >90%.     

Molecular transport of methane, ethane and nitrogen and the influence of diffusion on the chemical and isotopic composition of natural gas accumulations

Laboratory experiments have been performed to determine diffusion coefficients of natural gas components (methane, ethane and nitrogen) and isotope fractionation effects under simulated in situ pressure (up to 45 MPa effective stress) and temperature conditions (50–200°C) in water‐saturated pelitic and coarse‐grained rocks. Effective diffusion coefficients of molecular nitrogen (0.39 × 10^?11 to 21.6 × 10^?11 m² sec^?1 at 90°C) are higher than those for methane (0.18 × 10^?11 to 18.2 × 10^?11 m² sec^?1 at 90°C). Diffusive flux rates expressed in mass units are generally higher for N₂ than for CH₄. Both methane and (to a lesser extent) nitrogen diffusion coefficients decrease with increasing total organic carbon (TOC) content of the rock samples because of sorption processes on the organic matter. This effect decreases with increasing temperature. Effective diffusion coefficients increase upon a temperature increase from 50 to 200°C by a factor of four. Effective diffusion coefficients and steady‐state diffusive flux decrease with effective stress. Stationary diffusive fluxes drop by 50–70% for methane and 45–62% for nitrogen while effective diffusion coefficients are reduced by 38% (CH₄) and 32–48% (N₂), respectively. Isotope fractionation coefficients of diffusive transport are higher for methane (?1.56 and ?2.77‰) than for ethane (?0.84 and ?1.62‰). Application of the experimental results to geological systems show that diffusive transport has only a low transport efficiency. Significant depletion of natural gas reservoirs by molecular diffusion is only expected in cases of very poor caprock qualities (in terms of thickness and/or porosity) and over extended periods of geological time. Under these circumstances, the chemical and isotopic composition of a gas reservoir will change and maturity estimates based on these parameters may be deceptive. To account for these potential effects, nomograms have been developed to estimate diffusive losses and apply maturity corrections.     

Climate injustice,criminalisation of land protection and anti-colonial solidarity: Courtroom ethnography in an age of fossil fuel violence

As plans for expanding fossil fuel infrastructure continue to ramp up despite threats to the planet, how are geographers to address the criminalisation and prosecution of peaceful acts of defending earth, water and land? Reflecting on a courtroom ethnography and debates spanning legal geography, political ecology and social movements studies, this article explores embodied struggles around oil, ‘justice’ and geographies of caring – discussing how Indigenous youth, grandmothers in their eighties and others were convicted of ‘criminal contempt’ for being on a road near an oil pipeline expansion project. The project (“Trans Mountain Pipeline Expansion”) was created to transport unprecedented levels of heavy oil (bitumen) across hundreds of kilometres of Indigenous peoples' territory that was never ceded to settler-colonial authorities in Canada. Focusing on a controversial injunction designed to protect oil industry expansion, the discussion explores the performativity of a judge's exercise of power, including in denying the necessity to act defence, side-lining Indigenous jurisdiction, and escalating prison sentences. Courtroom ethnography offers a unique vantage point for witnessing power at work and vast resources used by state actors to suppress issues fundamental to the United Nations Declaration on Rights of Indigenous Peoples and the Paris Climate Accord. It also provides a lens into the intersectional solidarity and ethics of care among those who dare to challenge colonialism and hyper-extractivism, inviting engagement with multiple meanings of ‘irreparable harm’ at various scales. The article calls for more attention to power relations, values and affects shaping courtroom dynamics in an age in which fossil fuel interests, climate crisis and settler-colonial control over courts are entwined in evermore-complex violent entanglements.     

Unconventional Gas in Australia: Towards a Legal Geography

Recent commentary on future research directions for legal geography highlights the need for studies that are historically grounded and focused on human–environment interactions in rural settings. As a current, controversial land use in Australia, unconventional gas (UG) development provides an ideal lens through which researchers can investigate these themes. Utilising emerging international literature and current Australian examples, this paper surveys major trends in the Australian literature relating to UG, before exploring some of the ways in which Australian legal geographers might contribute constructively to community debates around this resource. Seeking to encourage further analysis, this paper contributes to this developing literature by focusing on two key areas: the various legal actors involved in UG development in Australia (including their regulatory choices, spatial interpretations, expertise, and influence) and the implications for legal geography where attempts are made to establish ‘social licence’ through contractual arrangements between industry and individual landholders. This article also delves into the place of Indigenous Australians in relation to UG extraction and the questions this resource raises about land use conflicts in Australia more generally – offering suggestions for comparative international studies and further critique at the domestic level.     

Carceral labour: Offshore work relations,conflicts and local participation in Ghana's oil and gas industry

Local participation is crucial for linking the oil and gas industry to broader economies. Direct employment in the oil and gas industry, albeit often on a limited scale remains critical for the transfer of expertise and know-how in many developing economies. Focusing on the social construction of carcerality – a set of spaces, practices and relationships, the paper examines the carceralities of non-prison places such as offshore oil and gas infrastructures. With emphasis on oil rigs and Floating, Production, Storage and Offloading (FPSOs) vessels, the paper highlights the complex labour relations, negotiations and conflicts in offshore working environment and its impacts on local content and participation in Ghana's oil and gas industry. The paper shows that carceral techniques operate to limit the potentiality of career progress. Offshore labour practices and relations show the new kinds of carceral spaces being created through offshore extraction, and sheds light on how these carceral spaces depotentialize the labour force and reinforce global political economic inequalities.     

Transfer of hydrocarbons from natural seeps to the water column and atmosphere

Results from surface geochemical prospecting, seismic exploration and satellite remote sensing have documented oil and gas seeps in marine basins around the world. Seeps are a dynamic component of the carbon cycle and can be important indicators for economically significant hydrocarbon deposits. The northern Gulf of Mexico contains hundreds of active seeps that can be studied experimentally with the use of submarines and Remotely Operated Vehicles (ROV). Hydrocarbon flux through surface sediments profoundly alters benthic ecology and seafloor geology at seeps. In water depths of 500–2000 m, rapid gas flux results in shallow, metastable deposits of gas hydrate, which reduce sediment porosity and affect seepage rates. This paper details the processes that occur during the final, brief transition — as oil and gas escape from the seafloor, rise through the water and dissolve, are consumed by microbial processes, or disperse into the atmosphere. The geology of the upper sediment column determines whether discharge is rapid and episodic, as occurs in mud volcanoes, or more gradual and steady, as occurs where the seep orifice is plugged with gas hydrate. In both cases, seep oil and gas appear to rise through the water in close proximity instead of separating. Chemical alteration of the oil is relatively minor during transit through the water column, but once at the sea surface its more volatile components rapidly evaporate. Gas bubbles rapidly dissolve as they rise, although observations suggest that oil coatings on the bubbles inhibit dissolution. At the sea surface, the floating oil forms slicks, detectable by remote sensing, whose origins are laterally within ～1000 m of the seafloor vent. This contradicts the much larger distance predicted if oil drops rise through a 500 m water column at an expected rate of ～0.01 m s^?1 while subjected to lateral currents of ～0.2 m s^?1 or greater. It indicates that oil rises with the gas bubbles at speeds of ～0.15 m s^?1 all the way to the surface.     

旅游过程碳足迹评估——以舟山群岛为例

本文运用碳足迹分析方法构建了旅游过程碳足迹模型,并以舟山群岛为例进行了实证分析。研究结果表明：（1）舟山群岛旅游过程（包括旅游交通、旅游住宿、旅游景区游览、旅游餐饮、旅游废弃物）碳足迹为376587.8606t CO2-e,其中旅游交通碳足迹最大,其次是旅游住宿和旅游废弃物的碳足迹;（2）舟山群岛旅游交通碳足迹为291770.0365t CO2-e,其中游客乘坐飞机产生的碳足迹最大,占旅游交通总碳足迹的52%;（3）舟山群岛旅游生态效率非常高,其值为0.0369kgCO2-e/元。研究提出,发展低碳旅游是舟山群岛实现旅游可持续发展的重要途径。     

用示踪气体法检测文物展柜换气率技术研究

摘要文物展柜为文物的展示和保存提供了一个相对独立的空间,展柜密封度的高低影响着展柜内微环境调控的效果。为评价文物展柜的密封度,用示踪气体法检测展柜换气率,从检测便捷、安全和实验数据可靠角度分析比较了二氧化碳和乙烯的实验结果。结果显示,两种示踪气体均可用于检测展柜的密封度。其中,二氧化碳气体检测法比较方便,但其密度较大,易于沉降,检测结果偏低。环境湿度对二氧化碳示踪气体法检测的结果有一定影响。应用二氧化碳示踪气体法测试了多种展柜的换气率表明,各展柜的密封度有较大差别,每天换气率从0.1次到37次不等。检测结果提示,二氧化碳示踪气体法为评价展柜的密封度提供了一个简便易行的方法。     

Gas chromatographic identification of a resinous deposit from a 6th century storage jar and its possible identification

A deposit representing the original contents of a Byzantine storage jar from the castellum of En Boqeq (Israel) was analysed using gas chromatography and identified as a highly oxidized pine resin. This oleoresin may have been intended for caulking, waterproofing, or for blending with fats and oils to produce an unguent, and the limitations of inference dictated by the use of this technique are discussed.     

文物展柜密封性能检测方法研究

The ventilation rate of a museum showcase is an important indicator for evaluating its sealing performance. In order to evaluate the ventilation rate of a showcase accurately, objectively and scientifically, some details of the detection and evaluation methods were comprehensively studied on the basis of GB/T 36110—2018. The results show that in order to achieve a better fitting effect, the carbon dioxide concentration outside a showcase should be fixed—a fixed concentration between 300 X 10 and 600 X 10 (volume fraction) had little influence on the fitting results. The average ventilation rate of the showcase at each moment was obtained by the numerical calculation method. When the detection time was short, values were unstable and fluctuated greatly; after stabilization, they were close to the fitted ventilation rates. The initial carbon dioxide concentration had a great influence on the fitting results of ventilation rate. The initial concentration of carbon dioxide gas in a showcase should be basically fixed between 20 000 X 10" and 25 000 X 10 ~ (volume fraction) during detection, so that the testing results were comparable. The carbon dioxide mixture in the airtight showcase is relatively uniform, and no obvious dip occurred. The location of detection equipment has little influence on the fitting results of ventilation rate. If the fitted R reaches 0. 9, the results are considered valid, due to various errors in the detection process. © 2023, Sciences of Conservation and Archaeology. All Rights Reserved.