Decode the phenomenon of a series of volcanic domino rocks

Warming temperatures are believed to be one of the causes of many rock falls in the world. Specifically, how did this phenomenon affect?

According to The Atlantic, there were severe landslides in El Capitan rock in Yosemite National Park, California, USA, which is famous for adventurous climbers.

One of them, one death, is also the first mountain-related death in the park since 1999.

A day later, a large amount of rock continued to fall, estimated at 10,000m ³ .

The erect surface of the cliff El Capitan - (Photo: REUTERS).

The warmer the earth is, the more ice is falling

According to Roger Putnam, a climber and geologist at Moorpark College, these landslides are very geologically unusual.They happen like a domino: this leads to another, then leads to another.

Rock is not new in Yosemite, where the US National Park Service estimates that about 80 incidents occur every year.

However, although they occur regularly, scientists still believe that the warming temperature and the phenomenon of climate change may increase the phenomenon of landslides in Yosemite in particular and the world in general.

Landslides tend to occur in cliffs with many weak internal points , such as large and small cracks, making the rock structure unstable.

Roy Sidle, professor of geography at the Sunshine Coast University points out four main causes of Yosemite rock erosion: freezing - defrosting; humidification - drying process; temperature changes; and human impact (including climbing).

According to Putnam, most geologists now think that the freezing cycle - thawing is the main cause of rock erosion. Accordingly, the water has penetrated into the cracks during the winter snow rain, then spread out when frozen, creating a risk of structural instability.

However, in 2016, geologists in Yosemite National Park presented on Nature Geoscience, showing that most of the Yosemite rockfall occurred on hot, sunny days, not during cold temperatures.

Specifically, on hot sunny days, soil and rock also expand due to heat. As the thermal range between day and night or between summer and winter is increasing, the rocks have to expand and contract more, creating more holes and cracks.

Rock erosion causes road congestion - (Photo: ABC30 Fresno).

Increasing global temperatures make these days more frequent, meaning that ice falls at risk more often.

In addition, rising global temperatures contribute to melting glaciers and permafrost, which support rock structures.

According to Allen Glazner, a professor of geology at the University of North Carolina, this melting phenomenon does not leave an impact on the rockfall that is happening in Yosemite.

However, glaciers that have shrunk over the past century in the Sierra Nevada, California or permafrost are melting in colder places such as the Apls strip as one of the causes of rockfall.

Climate change can also affect the wet-drying cycle, one of the factors that can cause rock erosion. According to Glazner, sometimes the amount of water in a stone system may be overloaded, causing some parts to break.

At the same time, strong storms after a long time without storms also cause large volumes of water that can cause landslides.

Passive in anticipation

The unexpected landslides are very dangerous for climbers - (Photo: The Mercury News).

According to The Atlantic, it is still very difficult to determine in detail what effects of climate change cause frequent rock erosion. Things are quite complicated.

For example, less and less cold nights can reduce the amount of ice slides caused by freezing - thawing, on the other hand, hot and humid weather increases the number of landslides caused by expansion. about heat caused and by the amount of water overloaded.

"The impact of climate change on rock erosion in Yosemite can increase over time if the freezing-thaw cycle or the wet-drying cycle becomes common, especially when climate change is increasing. become more harsh, " said Sidle.

However, dealing with today's landslides is very difficult."At appropriate times, prediction is not really feasible ," Sidle said.

In addition, the 3D map of the El Capitan rocks designed by Putham and Glazner did not indicate where rocks fell at the end of September as sensitive locations.

Putnam said small rocks were often triggered by larger landslides, so the US National Parks often warned visitors when they recorded small falls. However sometimes it is not accurate.

Typically, everyone thought that the stone stopped falling on September 27, however, on September 28, rockfall occurred in a much larger number.