scholarly journals Methane hydrate emergence from Lake Baikal: direct observations, modelling, and hydrate footprints in seasonal ice cover

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. G. Granin ◽  
I. A. Aslamov ◽  
V. V. Kozlov ◽  
M. M. Makarov ◽  
G. Kirillin ◽  
...  
Keyword(s):  
Water Column ◽  
Lake Baikal ◽  
Methane Hydrate ◽  
Ice Cover ◽  
Transport Processes ◽  
Methane Hydrates ◽  
Initial Radius ◽  
Column Temperature ◽  
Baikal Water ◽  
Direct Observations

AbstractThis paper provides a novel report of methane hydrates rising from bottom sediments to the surface of Lake Baikal, validated by photo and video records. The ascent of hydrates in the water column was confirmed by hydroacoustic data showing rising objects with velocities significantly exceeding the typical speeds (18–25 cm s−1) of gas bubbles. Mathematical modelling along with velocity and depth estimates of the presumed methane hydrates coincided with values observed from echograms. Modelling results also showed that a methane hydrate fragment with initial radius of 2.5 cm or greater could reach the surface of Lake Baikal given summer water column temperature conditions. Results further show that while methane bubbles released from the deep sedimentary reservoir would dissolve in the Lake Baikal water column, transport in hydrate form is not only viable but may represent a previously overlooked source of surface methane with subsequent emissions to the atmosphere. Methane hydrates captured within the ice cover may also cause the formation of unique ice structures and morphologies observed around Lake Baikal. Sampling of these ice structures detected methane content that exceeded concentrations measured in surrounding ice and from the atmosphere demonstrating a link with the methane transport processes described here.

Governing the transboundary risks of offshore methane hydrate exploration in the seabed and ocean floor—an analysis on international provisions and Chinese law†

2020 ◽  
Vol 13 (2) ◽  
pp. 185-203
Author(s):  
Dong Yan ◽  
Paolo Davide Farah ◽  
Tivadar Ötvös ◽  
Ivana Gaskova
Keyword(s):  
Methane Hydrate ◽  
Human Life ◽  
Damage Control ◽  
Legal Framework ◽  
Environmental Harm ◽  
Methane Hydrates ◽  
International Role ◽  
Deep Seabed Mining ◽  
The Cost ◽  
The Unclos

Abstract Considering the fact that its existence is abundant while maintaining the ability to generate freshwater while burning, methane hydrates have been classified as sources of sustainable energy. China currently maintains an international role in developing technology meant to explore offshore methane hydrates buried under the mud of the seabed, their primary laboratory being the South China Sea. However, such a process does not come without its hazards and fatal consequences, ranging from the destruction of the flora and fauna, the general environment, and—the greatest hazard of all—the cost of human life. The United Nations Convention on the Law of the Sea (hereinafter ‘UNCLOS’), being an important international legal regime and instrument, has assigned damage control during the exploration of methane hydrates, as being the responsibilities and liability of individual sovereign states and corporations. China adopted the Deep Seabed Mining Law (hereinafter the DSM Law) on 26 February 2016, which came into force on the 1 of May 2016; a regulation providing the legal framework also for the Chinese government’s role in methane hydrate exploratory activities. This article examines the role of the DSM Law and its provisions, as well as several international documents intended to prevent transboundary environmental harm from arising, as a result of offshore methane hydrate extraction. Despite the obvious risk of harm to the environment, the DSM Law has made great strides in regulating exploratory activities so as to meet the criteria of the UNCLOS. However, this article argues that neither the UNCLOS nor the DSM Law are adequately prepared to address transboundary harm triggered by the exploitation of offshore methane hydrates. In particular, the technology of such extraction is still at an experimental stage, and potential risks remain uncertain—and even untraceable—for cross-jurisdictional claims. The article intends to seek available legal instruments or models, to overhaul the incapacity within the current governing framework, and offers suggestions supporting national and international legislative efforts towards protecting the environment during methane hydrate extraction.

scholarly journals Formation of a Low-Density Liquid Phase during the Dissociation of Gas Hydrates in Confined Environments

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 590
Author(s):  
Lihua Wan ◽  
Xiaoya Zang ◽  
Juan Fu ◽  
Xuebing Zhou ◽  
Jingsheng Lu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Methane Hydrate ◽  
Phase State ◽  
Solid Phase ◽  
Potential Method ◽  
Methane Hydrates ◽  
Low Density ◽  
Hydrate Dissociation ◽  
State Of Water ◽  
Confined Environment

The large amounts of natural gas in a dense solid phase stored in the confined environment of porous materials have become a new, potential method for storing and transporting natural gas. However, there is no experimental evidence to accurately determine the phase state of water during nanoscale gas hydrate dissociation. The results on the dissociation behavior of methane hydrates confined in a nanosilica gel and the contained water phase state during hydrate dissociation at temperatures below the ice point and under atmospheric pressure are presented. Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) were used to trace the dissociation of confined methane hydrate synthesized from pore water confined inside the nanosilica gel. The characterization of the confined methane hydrate was also analyzed by PXRD. It was found that the confined methane hydrates dissociated into ultra viscous low-density liquid water (LDL) and methane gas. The results showed that the mechanism of confined methane hydrate dissociation at temperatures below the ice point depended on the phase state of water during hydrate dissociation.

Effect of extremely severe winters on under-ice phytoplankton development in a mesotrophic lake (Eastern Poland)

2014 ◽  
Vol 43 (2) ◽  
Author(s):  
Władysława Wojciechowska ◽  
Tomasz Lenard
Keyword(s):  
Water Column ◽  
Dominant Species ◽  
Biomass Concentration ◽  
Thermal Conditions ◽  
Ice Cover ◽  
Abundant Species ◽  
Blue Green Algae ◽  
Cyanobacteria And Algae ◽  
Taxonomic Groups ◽  
The Vertical Distribution

AbstractThe research was carried out in a mesotrophic and dimictic lake during winters with ice cover. In the last forty years, the development of phytoplankton was analyzed in five extreme winter seasons. The studies of phytoplankton characteristics in the water column took into account values of biomass, concentration of chlorophyll-a and species composition, including dominant species. Differences in the vertical distribution of flagellate and non-flagellate species belonging to cyanobacteria and algae were analyzed in the gradient of light and thermal conditions. The phytoplankton biomass was low and vertically differentiated, with the lowest values at the deeper part of the water column. Flagellate species from the group of Cryptophyceae, Chrysophyceae and Dinophyceae were most abundant. Species biodiversity was low but every winter the dominant species represented different taxonomic groups. In some periods, larger non-motile phytoplankton species from green or blue-green algae dominated. The research proved that the development of phytoplankton under the ice cover was limited mainly by light and, to a lesser extent, by temperature.

Current chemical composition of Lake Baikal water

Inland Waters ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 250-258 ◽  
Author(s):  
Tamara V. Khodzher ◽  
Valentina M. Domysheva ◽  
Larisa M. Sorokovikova ◽  
Maria V. Sakirko ◽  
Irina V. Tomberg
Keyword(s):  
Chemical Composition ◽  
Lake Baikal ◽  
Baikal Water

Lake Baikal: water turbidity monitoring and bathymetry with an airborne lidar

1999 ◽  
Author(s):  
Grigorii P. Kokhanenko ◽  
Ioganes E. Penner ◽  
Vitalii S. Shamanaev ◽  
Geoff D. Ludbrook ◽  
Andrew M. Scott
Keyword(s):  
Lake Baikal ◽  
Airborne Lidar ◽  
Water Turbidity ◽  
Baikal Water

Microbe-Worm Symbiosis Stabilizes Methane Hydrates in Deep Marine Environments

2021 ◽  
Author(s):  
Tianyi Hua ◽  
Maisha Ahmad ◽  
Tenzin Choezin ◽  
Ryan Hartman
Keyword(s):  
Methane Hydrate ◽  
Temperature Fluctuations ◽  
Methane Hydrates ◽  
Natural Ecosystem ◽  
Ocean Temperature ◽  
Marine Environments ◽  
Balance Equations ◽  
Temperature Records ◽  
Living Organisms ◽  
Hydrate Stability

Abstract Our Planet has a natural ecosystem comprised of living organisms and methane hydrates in deep marine environments. This ecosystem was constructed in the present work to examine the influence that subtle temperature fluctuations could have on the dynamic stability of the hydrate deposits. The coupled mass and energy balance equations that describe the microbial bioreactions, their consumption by feather duster worms, and methane hydrate dissociation confirm that the bioreaction kinetics are dominated by endothermic methanogenic metabolism that stabilizes methane hydrates with a fragile tolerance to 0.001K temperature increases. The feather duster worms also stabilize the hydrates via their selective consumption of methanotrophs that could otherwise overtake the system by their exothermic metabolism. Critical ocean temperature limits exist, beyond which hydrate dissociations would cause underwater eruptions of methane into the sea. Historical ocean temperature records and gas hydrate inventory estimates combined with our model suggests that hydrate deposits as deep as 560-meters below sea level could already be at risk, whereas the methane hydrate stability zone will retreat deeper as ocean temperatures rise. Slowing its retreat could avoid the massive release of greenhouse gas.

Phytoplankton Biomass and Water Column Temperature Dynamics of Lake James, NC USA

2004 ◽  
Vol 1 (1) ◽  
pp. 23-26
Author(s):  
Kemal Celik ◽  
James Schindler . ◽  
William Foris . ◽  
Jonathan Knight .
Keyword(s):  
Water Column ◽  
Phytoplankton Biomass ◽  
Column Temperature ◽  
Temperature Dynamics ◽  
Lake James

The use of Satellite Imagery in Investigating the Dynamics of the Ice and Snow Cover Lake Baikal

2003 ◽  
Vol 34 (1-2) ◽  
pp. 33-50 ◽  
Author(s):  
S.V. Semovski ◽  
N. Yu Mogilev
Keyword(s):  
Snow Cover ◽  
Lake Baikal ◽  
Satellite Imagery ◽  
Ice Cover ◽  
Unfrozen Water ◽  
Processing Strategy ◽  
Noaa Avhrr ◽  
Satellite Information ◽  
Process Studies ◽  
Snow And Ice

The generation and sample applications of a set of multispectral remotely sensed products for investigations of Lake Baikal's ice cover variability are described. During the period from mid-January to the end of April, the lake is completely covered with ice, and by analyzing satellite information it is possible to investigate in detail the distribution and dynamics of the main types of snow and ice cover. Different ice cover classes and unfrozen water distributions are estimated from calibrated and navigated NOAA AVHRR 1.1-km imagery of Lake Baikal for January 1994 through May 1999. The processing strategy and characteristics of the products are reviewed. The utility of this type of multiparameter dataset for modelling applications and process studies is discussed. ERS SAR and Resurs images are used for detailed representation of different ice classes distributions.

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