Sunday, May 25, 2014

Tectonic shift

ASIA TOOK billions of years to build. It started with Siberia and then huge land masses like Mongolia and China got added. India collided with south Asia, giving birth to the towering Himalayas.

Fissures and faultlines

Asia rests on tectonic plates that are still active. The plates push into each other, separate and collide. The Indian plate continues to dig right into its Asian neighbour. This mammoth and uncontrollable event might even cause a catastrophe in Nepal, a tiny country wedged between India and the rest of the continent. Some scientists believe that this peaceful landscape is concealing a colossal energy that could cause a major earthquake. Seismological studies show that every year, the Himalayas move 2-4 cm. It may not seem much, but it means one metre per human lifetime. In terms of millions of years, this is enormous. In fact, it is one of the fastest-moving places on the planet.

Nepal’s last major earthquake occurred more than 300 years ago. That’s a 300-year build-up of tectonic energy waiting to be released. The threat to Kathmandu, the country’s largest city, is growing closer. Although everyone knows that there’s a high risk of earthquakes in Nepal, all the buildings still have very weak foundations and they’re being built higher than ever.

The tectonic pressure of the Indian plate threatens more than just Nepal. Further north, in western China, another network of faults splits the continent. This fragile zone, the Tibetan Plateau, has on its northern borders a mountain chain parallel to the Himalayas called the Kunlun Mountains. These mountains form a 3,000-km-long geological barrier that is resisting the movement of the Indian plate. It is literally keeping China from being pushed northwards. It’s the Tibetan Plateau that’s doing the heavy work of absorbing the impact of the Indian plate.

The Indian tectonic plate is so powerful that it’s actually pushing Tibet up against Kunlun Mountains. It’s also pushing the whole Tibetan Plateau and part of China to the east along the Kunlun Fault.

The large faults of the Tibetan Plateau have affected the geography of Asia, sometimes in spectacular ways. A few hundred kilometres in inner Mongolia, the Badain Jaran desert owes its unique appearance to the tectonics of Tibet and Kunlun Mountains. The dunes are part of the highest desert in the world with crests over 500 m high. Unlike the dunes of the Sahara, which are sculpted by the wind, Badain Jaran dunes are unchangeable. Even more surprising are the 75 permanent lakes that adorn the base of the dunes. Their existence has long been a puzzle to scientists.

Chinese checkers to find faults

On May 12, 2008, an earthquake that registered 8 on the Richter Scale devastated Sichuan. It wiped out a city of 20,000 people, cut mountains, villages and houses in two and caused over 70,000 deaths. In the 1970s, cold war tensions led to the Chinese government building several factories in this secluded mountainous region. Planners were unaware that they were building right in the heart of the most earthquake-prone regions of the planet. Despite the tragedy, new buildings, less than 50 m from the fault, are coming up unmindful of the danger beneath. Though Chinese authorities may be slow to impose stricter construction standards in the region, they are investing in research. The Chinese scientific community is trying to deal with the permanent tectonic threat that hangs over the region.

Teams work here day and night, hoping to extract precious knowledge buried deep in the earth. The equipment they’re using is normally employed in the search for minerals or oil. In this case, they’re drilling non-stop several hundred metres down, hoping to understand what’s happening in the fault responsible for the devastating 2008 earthquake. At this rate, China is destined to become a world leader in earthquake prevention, especially in understanding the tectonic forces that so deeply affect their own country.

The Pacific Ring of Fire

Japan is situated in the most unstable region of earth. For hundreds of millions of years, it was attached to the eastern coast of the Asian continent. About 15 million years ago, the subducting plates of the Pacific pulled Japan eastwards, opening up Sea of Japan. The entire country sits atop the meeting point of the Pacific, Filipino and Asian plates. This earthquake and volcano zone is known as the Pacific Ring of Fire. From time immemorial, the Japanese have had to adapt to the instability of earth beneath their feet.

In the vast megalopolis of Tokyo, almost 35 million people are crowded into one of the most fragile zones of earth’s crust. Because of this, the city’s buildings are designed to withstand the most violent tremors.

As if earthquakes weren’t bad enough, Japan is also threatened by frequent volcanic eruptions. The country is sitting on a geological powder keg. Underneath the country, the Pacific plate is sinking under the weight of the Asian plate.

The resulting subduction has created the Izu archipelago, a volcanic arc of explosive islands. The most famous of Japanese volcanoes is Mt Fuji, formed several hundred thousand years ago. Fuji has erupted dozens of times and each lava flow has lifted the mountain higher. At present, it towers more than 3,700 m over Japan. Despite this peaceful appearance, many scientists believe that Mt Fuji poses a major risk for the entire south-eastern part of Japan.

Java, the hyperacid lake and gaseous gold

The volcanism of the Pacific Ring of Fire is at its most dangerous on the island of Java in Indonesia. There are at least 20 active volcanoes on the island. Among the most famous are Bromo and Semeru, both of which threaten to erupt at any moment. It’s a wonderful place for those who study volcanoes. Kawah Ijen, a beautiful blue lake, is highly deceptive. It is one of the most active Indonesian volcanoes. This is truly a phenomenal location, which hosts the world’s largest and most hyperacid lake. It has a pH of zero (pH is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7). So it’s as strong as any car battery acid.

Nearby, a sulphur mine has been in operation since 1759. In earlier times, these gases were harnessed to produce gunpowder. Today, workers are risking their lives to obtain sulphur whose only use is to turn brown sugar into white. Researchers believe that Kawah Ijen might be able to produce something much more valuable than sulphur—gold in its gaseous form, touted to be a baby goldmine. This gold would have formed hundreds of kilometres underground, down where the archipelago’s tectonic plates converge. In the village of Pacitan, scientists from many disciplines are working together to solve the mystery and are trying to map the history of humans on Java, a history, which began almost two million years ago.

The tectonic rise of Asia

Asia, undoubtedly, is our planet’s most dynamic land mass. The immensely powerful tectonic motor that is constantly transforming it has been working full throttle for more than three-and-a-half billion years. It was on the shores of the legendary Lake Baikal in the heart of Siberia that scientists discovered the oldest parts of Asia. Only 100 km west of Lake Baikal, a huge mountain chain dominates the landscape. It was in these mountains that geologists first discovered volcanic evidence that showed that the tectonic plates were moving apart. When the plates separated, molten matter rose to the surface, creating flows of the red volcanic material. This, together with the presence of a mountain chain, proves that the bottom of Lake Baikal is literally splitting open.

On the east and west sides of the lake, the shorelines are moving apart by a few centimetres a year. In a few million years, if this seemingly irresistible tectonic movement continues, the lake will turn into an inland sea, which could then become an ocean. Asia would then be divided into two. Meanwhile, to the south, India keeps its pressure on China, pushing it off the continent. It is now known that the tectonic forces in Asia are a greater threat to human life than in any other part of the world. Yet this same energy provides humanity with resources, allowed our ancestors to settle in new territories and gave them shelter by carving monumental structures out of rock.

Voyage of the Continents airs every Wednesday at 8 pm

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