Some countries are trying to drill and exploit natural gas hydrate (NGH).

A lot of Earth's methane is trapped below the seabed as " gas hydrate", an ice-like crystal of methane and water.

The US launched a national research and development programme as far back as 1982, and by 1995 had completed its assessment of gas hydrate resources.

This expedition was part of a larger international project focusing on the interactions between gas hydrates and slow-moving landslides.

A buildup of slushy gas hydrates stymied its first attempt at covering the rupture with a huge metal dome.

As ocean temperatures change, the methane hydrate system has the potential to become unstable.

This image shows a chunk of burning methane hydrate.

It's where you heat the Earth to the point where the Arctic methane hydrate shelf starts to melt.

They'd also like to find out whether methane hydrate deposits vary in composition, concentration and behavior with depth.

Underneath the ocean surface way down deep, there are huge deposits of frozen methane gas, it's called methane hydrate.

Some countries are trying to drill and exploit natural gas hydrate (NGH).

Whole nations were bankrupted trying to get there, to dwarf stars and planets of methane ice.

The ridges were only a meter high and a couple of meters across, dirty water and methane ice fused smooth as glass.