East Sea, Becoming a Submarine Landslide Time Bomb?

As East Sea water temperatures rise, the very zone where gas hydrates can stabilize as ice is deepening. This leads to the melting of gas hydrates that were in shallower areas.

These vaporized gases erupt through submarine sediment layers, cracking the ground and becoming a major cause of increased submarine landslide probability.

Regarding the Nepal landslide, some Western glaciologists attempted to use it for global warming campaigns even before proper investigations into its cause were conducted. However, such hasty attribution of causation should be avoided.

It is scientifically sound to discuss the impact of global warming only after precisely analyzing the exact causes of landslide occurrences.

Himalayan peaks rise sharply as rock, but the ice accumulated on them also shapes the terrain. Glaciers carve out gentle U-shaped valleys, and in the past, they supported mountain slopes, maintaining stable pyramidal glacier structures.

However, as glaciers retreat due to climate change, the lower support for the mountain slopes disappears. Particularly, the loss of the lower glacier destabilizes steep slopes, increasing the risk of large-scale landslides.

Glaciers, being solid, provided rigidity and acted as a form of reinforcement, supporting the mountain slopes. But as glaciers melt away, this supporting role vanishes.

If the Earth warmed slowly, even if lower glaciers disappeared, upper glaciers could slowly flow down to replenish the lost mass. However, the current rate of glacier melt is too rapid for such replenishment to occur effectively.

Consequently, only upper glaciers remain while lower ones disappear, accelerating the instability of mountain slopes. Geological stability requires the maintenance of a pyramidal glacier structure, but rapid warming is disrupting this balance.

To scientifically conclude the impact of climate change on specific disasters, it is necessary to analyze data from the past ten thousand years. Evidence regarding glacier movement patterns and landslide frequencies must be substantiated.

Comparing landslide frequencies before and after industrialization is essential, and systematic evidence substantiation should take precedence over premature conclusions. Scientists can only state that global warming has had a significant impact on disasters when sufficient evidence is secured.

The rate of glacier disappearance in the past 100 years since industrialization is astronomically faster compared to the rate over the past 15,000 years. When glaciers recede slowly, replenishment from above is possible, but at the current rapid speed, it leads to slope instability.

Such rapid change does not allow natural reinforcement mechanisms to operate, severely undermining terrain stability.

There are no glacial lakes at the Nepal landslide accident site; they have all dried up. Instead, it is presumed that piles of rocks and ice masses swept down, forming a natural dam.

This suggests the possibility of a disaster caused by geological changes other than glacial lake outbursts.

Locally in Nepal, there is a strong perception that this sudden catastrophe is an effect of global warming, and accountability lies with external countries, such as developed nations. Nepal is one of the countries with the lowest carbon dioxide emissions globally, yet it is suffering the consequences of the climate crisis.

Thus, voices are being raised, asking, "Why should we suffer such damages because of you?"

Installing solar panels over large areas in mountainous regions can be considered a very risky endeavor. This is because the installation process can destroy vegetation, weakening the supportive capacity of mountain slopes.

Concrete reinforcement alone is insufficient to prevent sudden floods and landslides, and environmental destruction could exacerbate disaster risks.

Methane hydrate, existing in a solid state where pressure and temperature conditions are met beneath the East Sea seafloor, is also known as 'burning ice.' It has drawn attention for its potential as an energy resource.

However, as global warming causes water temperatures to rise, the stabilization zone for methane hydrate deepens, and the solid methane begins to vaporize into gas.

As methane gas vaporizes due to rising water temperatures, it disturbs the seafloor as it erupts through submarine sediment layers. This disturbance significantly reduces the cohesion and stability of the submarine topography.

Consequently, increased seafloor instability acts as a factor that further raises the risk of submarine landslides.

Gas hydrates are extensively distributed throughout the East Sea, from the coastal slopes to the seafloor around Dokdo, making it hard to find areas without them. This is assessed as a critical risk factor that could cause significant problems for the slope stability of the entire East Sea.

Such wide distribution implies that geological risks due to temperature changes exist throughout the East Sea.

To extract solid gas hydrates, hot water must ultimately be injected underneath to melt and extract the gas. However, this method is not cost-effective and lacks economic feasibility.

Furthermore, the hot water injection process has the potential to induce additional geological risks such as earthquakes, posing not only technical challenges but also environmental hazards.

The sharp topography of the Himalayan high mountains was formed by repeated collapses over a long period. However, a large-scale collapse like the Langtangri incident, measuring 5.2, is not common.

Professor Kim Ki-bum argued that when considering how often such large-scale landslides occur, it is reasonable to view them as rare events that happen perhaps once every 100 years.

Therefore, recent large-scale landslides cannot be simply regarded as everyday phenomena, and their recurrence interval needs to be analyzed from a long-term perspective.

When glaciers were connected to the lower end of mountain slopes, the glacier itself, being solid and rigid, acted as a form of reinforcement, supporting the slope. However, due to climate change, lower-lying glaciers are rapidly disappearing, removing this supportive role.

The loss of glaciers directly leads to a rapid weakening of the slope's supportive capacity, thereby increasing the overall instability of the mountain slope. This is a direct cause of increased landslide risk.

If global warming occurred slowly, even if lower ice disappeared, upper ice could slowly flow down as glaciers, providing time to reinforce the base again. However, the current speed of global warming is too rapid, preventing this reinforcement mechanism from operating.

In other words, there is no time for upper glaciers to flow down and reinforce the slope. This means that the rate of glacier loss significantly outpaces the glacier's capacity for reinforcement.

This imbalance rapidly weakens the supportive capacity of mountain slopes, further increasing the risk of large-scale slope collapses.