Tsunami terror lurks along Gujarat’s coast

DNA Special

There are chances of an 8.5 magnitude tsunami originating from Makran coast, says report

AHMEDABAD: Imagine a scenario in which Hazira, Mundra, and Kandla ports disappear into angry seas overnight, and the Rann of Kutch is reduced to half its size. The forbidding picture is not a result of far-fetched imagination, but an ominous reality. The devastation described would be the consequence of a tsunami bringing a frightening surge of 10 metre high waves across Gujarat's 1,600km long coastline, the mainstay of the state's economic development.

In 2004, an enormous subterranean energy in India's eastern coast was released which led to the tsunami that devastated 11 Asian countries. What has the seismologists worried is the realisation that a similar phenomenon has not occurred on the western coast for quite some time. The last major tsunamis occurred in the region in 1845 and 1945, wrecking Gujarat.

Experts said that the state sits adjacent to one of the world's hotbeds for seismic activities—the Makran coast in the Arabian Sea—350km off the coast of Narayansarovar, Kutch. "The 2004 tsunami caused a release of energy in the Indian Ocean, but there has been no such energy release in western part of India," said the director-general of the Institute of Seismological Research (ISR), Gandhinagar, BK Rastogi.

"Hence the probability of a tsunami originating in the Arabian Sea is much higher now. A 6 magnitude earthquake was reported from the Makran coast just eight months ago."

Drawing data from an ongoing study, the ISR has estimated the damage that a tsunami can cause. "It is a ticking bomb that could explode any day. There is a possibility of an 8.5 magnitude tsunami which can create a wave as high as 10 metres," Rastogi said. "Originating from the Makran coast, the waves can wash out up to 3km of Gujarat coast and nearly half of Kutch. The state's map would change completely. Parts of Maharashtra and Bombay High will also be affected."

The highest wave of the 2004  tsunami was 24 metres in the sea; the quake was of the magnitude of 9.1 to 9.3. The ISR estimates that if a 10 metre high wave does strike, the devastation it can cause will wipe out the state's entire coastline and half of Kutch comprising Jamnagar, Gandhidham, and Surat.  

Prosperous ports like Kandla, Mundra, and Hazira, around which the government is planning the state's future, could disappear without a trace.  "Along with a substantial loss of life, ports, salt industry, fisheries and chemical industries will be heavily affected," Rastogi said.

The state's history of tsunami strikes offers a horrific catalogue of destruction. In 1845, a tsunami of 8 magnitude originated in the Arabian Sea and struck Kutch. In 1945, a tsunami of 7.8 magnitude originated in Pakistan, along the Makran coast, and set off a wave as high as 13 meters. The tsunami killed more than 4,000 people.

While the minimum time gap between two tsunamis at the Makran zone has been recorded as 13 years, the maximum boundary is limited to 97 years. The last tsunami originated from the Makran coast 62 years ago.

Seismic activity in the Arabian Sea is being closely watched by many countries because any tsunami originating there will affect Pakistan, Iran, and possibly even North Africa. There are seven major and more than ten minor tectonic plates on the earth. The Himalayas were formed due to the collision of two tectonic plates, the Indo-Australian and the Eurasian.

"Three tectonic plates meet at the Makran coast. This makes the area very volatile, with the tectonic plates constantly colliding with each other and releasing immense energy," said an ISR scientist, Sumer Chopra. 

s_bhardwaj@dnaindia.net