Mountains rise, they stand tall, they even loom. But did you know they breathe?
Click start to play today’s Crossword, which takes you on a trip across the highlands of the Middle East, Central Asia, and North Africa.
Like the chest of a sleeping giant, mountains literally rise up in a drawn breath, and then sink back down on an exhale, when the stress from tectonic collisions generates earthquakes. In an April 2021 study published in the UK-based journal Nature Reviews, scientists examined over 200 past studies based on the Himalayas, to understand how such geological respirations occur.
While such ‘breaths’ happen in mountain ranges all over the world, the study researchers chose the Himalayas because of its vast expanse and geological complexity. The entire range came about, after all, from a similar tectonic build-up about 50 million years ago, when the Indian continental plate crashed into the Eurasian plate. At that meeting point, both continents compressed, and India pushed north, shoving beneath Eurasia. Like a curtain’s fabric bunching up when you push the lower edges of the material upwards, the landscape crumpled and creased, forming the majestic peaks of the Himalayas.
According to a May 2021 National Geographic report, even today, India continues to push north, at a rate of nearly two inches per year. But it’s not a smooth journey – the Eurasian plate bulges and bunches up, and the land sees a great amount of stress, driving the mountains to rise higher and higher. When the stress hits a threshold, a massive earthquake causes the landmasses to shift and settle, like a pent-up cough or an exhale.
This happened in 2015, when a 7.8-magnitude earthquake levelled over 600,000 structures in Kathmandu, Nepal, and killed about 9,000 people. It also caused a whole swath of the Himalayas to sink by two feet!
Researchers are now analysing all aspects of geological activity in the Himalayas to make sense of the way earthquakes unfold. From looking at the shape of the fracture between the two tectonic plates – the Himalaya’s fault line extends to 2,253km – to studying the scars left from historical quakes, to crafting a complete map of the fault’s twists and turns, it’s a daunting task. But with studies like these, researchers hope to learn about how future earthquakes will unfold and which communities may be most at risk.