Which of the following statements are correct about the deposits of 'methane hydrate'? 1. Global warming might trigger the release of methane gas from these deposits. 2. Large deposits of 'methane hydrate' are found in Arctic Tundra and under the seafloor. 3. Methane in atmosphere oxidizes to carbon dioxide after a decade or two. Select the correct answer using the code given below.

States that methane is emitted by natural sources (wetlands) and from soil/atmospheric processes — showing methane is stored and released naturally from Earth systems.

A student could extend this by noting that if natural reservoirs (e.g., sediments, wetlands) release methane under present conditions, warming that alters those reservoirs (temperature, water/ice cover) might increase such releases.

Explains methane is produced by anaerobic processes (organic matter decaying without oxygen) often in underwater or sedimentary settings.

One could infer that warming-induced changes to submerged or frozen sediments could change anaerobic conditions and mobilize stored methane.

Notes that the world is warming, glaciers are melting and sea level is rising — i.e., warming alters cryosphere and ocean conditions.

Using basic geography, a student can link warming-driven melting/temperature rise to thawing permafrost or warming continental margin sediments where hydrates occur, potentially releasing methane.

Says natural gas is found with petroleum deposits and is released when crude oil is brought up — indicating methane exists in geological reservoirs and can be liberated by changes or disturbance.

A student could reason that geological/thermal changes (e.g., warming or destabilization) might similarly free methane from other subsurface reservoirs like hydrates.

Gives methane a high short-term global warming potential and notes its atmospheric lifetime — implying that any sudden release would have a strong near-term climate effect.

Combining this with a plausible warming-driven release, one can assess the potential feedback strength even if the exact release mechanism isn't specified here.

Defines tundra as a region of permafrost where the subsoil is permanently frozen.

A student could combine this with the basic fact that methane hydrate forms in permanently cold, water‑saturated sediments to infer these regions are candidate settings for hydrates.

States distribution of Arctic tundra as continuous belt in high latitudes (northern fringe of Canada, Alaska, Siberia) — identifies geographical areas with permafrost.

Using a world map, a student could locate these high‑latitude permafrost zones and compare them to known hydrate‑prone regions to assess plausibility.

Describes tundra soils as poorly developed, characterised with permafrost and only surface horizons thawing in summer producing mucky, poorly drained surfaces.

A student could use the connection between water‑saturated, frozen sediments and hydrate stability to judge whether such soils might host methane hydrates beneath the active layer.

Notes lowlands with a few months ice‑free have tundra vegetation and permanently snow‑covered highlands — reinforces presence of seasonally thawed surface over frozen ground.

Combine this seasonal thaw/frozen profile with the basic rule that hydrates require cold temperatures and saturated sediments to evaluate the potential for subsurface hydrate occurrence.

Mentions brief summer thaws and emergence of surface water/poor drainage on tundra.

A student could extend this by noting that standing water and saturated sediments during thaw increase conditions (water availability + low temperature below active layer) that are relevant to hydrate formation or preservation.

Describes slow accumulation of terrigenous and other particles as layered sediments on the ocean floor, establishing that substantial sedimentary deposits exist beneath the seafloor.

A student could combine this with the fact that methane hydrates form within sediments to infer where such deposits might be preserved beneath the seafloor (e.g., thick continental margin sediments).

Explains that oil and natural gas originate from organic matter in shallow marine sediments and are found in sedimentary basins, linking hydrocarbons to marine sedimentary environments.

From this pattern, a student could reason that other hydrocarbon-related phases (like methane in different forms) may also be associated with marine sediments and seek specific formation conditions for hydrates.

Notes abyssal plains as deposition zones where continental sediments transported beyond margins are deposited, indicating large-scale sediment accumulation in deep-sea settings.

A student could use a map of continental margins and abyssal plains to identify broad areas with thick sediments that could host subsurface compounds in those sediments.

States that deep-sea plains are extensively covered by terrigenous and shallow-water sediments and occupy 40% of the ocean floor, indicating widespread sedimentary cover at depths.

Combined with knowledge that pressure increases with depth and that sediments can trap gases, a student might infer large potential areas beneath the seafloor where gas-related deposits could exist.

Mentions natural seeps leaking large quantities of oil into the sea over geological time, showing that subsurface hydrocarbon reservoirs and pathways to the seafloor exist.

A student could link the existence of subsurface hydrocarbon systems and seeps to the possibility of other subsurface hydrocarbon phases (like methane trapped in sediments) and then check conditions favoring hydrate stability.