Indian collision with Asian underbelly led to quake: Dam and massive reservoir near epicentre may have contributed to geological changes that weakened fault zones

INDIA is bashing into the soft underbelly of Asia at the rate of about 5cm (2in) a year. The most obvious results of this activity are Mount Everest, the Himalayas, and massive earthquakes north of the Ganges marking the boundary between the two colliding geological structures.

Less obvious, however, is that the whole of India feels the effect of the collision. There is stress and compression in the rocks, which is occasionally relieved in the form of earthquakes that occur far from the Himalaya mountains, such as the one that hit the towns of Umbarga and Khilari, some 450km (280 miles) east of Bombay in Maharashtra state, this week.

According to James Jackson, of the Department of Earth Sciences at Cambridge University, the event may be associated with the presence of a massive reservoir nearby. 'Big reservoirs can induce earthquakes,' Dr Jackson said, 'although the mechanism is not well understood.'

The Koyna dam near Khilari, a small town with a population of about 20,000, was full at the time of the earthquake but did not burst. The weight of water in the reservoir can contribute more stress but - more important - some of the water will percolate into subterranean fault zones and weaken them, Dr Jackson said. This is not so much a matter of the water acting as lubricant as actually weakening the material itself.

The Bombay meteorological bureau said there was a succession of five tremors that shook western and southern India. The first, at 3.56am, measured at least 6.4 on the Richter scale. In Golden, Colorado, the US Geological Survey described the earthquake as the largest in the area since 11 December 1967, when a shock of 6.5 magnitude was felt some 270km (170 miles) west of the epicentre of this week's quake.

According to Chris Browitt of the British Geological Survey's Global Seismology Unit, 'Earthquakes of this magnitude happen about 80 times every year across the world.' This earthquake proved especially damaging because it was geologically shallow, thus allowing a great deal of earth movement to affect a highly populated area at the surface of the Earth's crust.

There is no direct relationship between the magnitude of an earthquake, as measured on the Richter scale, and the damage that results. Much larger earthquakes can cause many fewer casualties if they happen in remote areas. The death toll from this week's earthquake in India is high partly because it struck at night, when most people were indoors, and because buildings in the affected area were not designed to withstand seismic events and collapsed, crushing their occupants.

But Dr Jackson pointed out that in 1897 and 1905 there were 'enormous earthquakes' of magnitude 8 or greater along the foothills of the Himalayas. The event in Maharashtra state 'is a lot smaller', he said. He warned that there would be huge casualties if another magnitude 8 event were to strike northern India again.

(Graphics omitted)

Have you tried new the Independent Digital Edition apps?
ebookA unique anthology of reporting and analysis of a crucial period of history
Life and Style
Arts and Entertainment
Southern charm: Nicolas Cage and Tye Sheridan in ‘Joe’
filmReview: Actor delivers astonishing performance in low budget drama
Arts and Entertainment
While many films were released, few managed to match the success of James Bond blockbuster 'Skyfall'
Arts and Entertainment
Up my street: The residents of the elegant Moray Place in Edinburgh's Georgian New Town
tvBBC's The Secret History of Our Streets reveals a fascinating window into Britain's past
Albus Dumbledore, the headmaster of Hogwarts School of Witchcraft and Wizardry has been the teaching profession's favourite teacher
Luis Suarez looks towards the crowd during the 2-1 victory over England
Life and Style
Cheesecake frozen yoghurt by Constance and Mathilde Lorenzi
food + drinkThink outside the cool box for this summer’s frozen treats
John Barrowman kisses his male “bride” at a mock Gretna Green during the Commonwealth Games opening ceremony
peopleBarrowman's opening ceremony message to Commonwealth countries where he would be sent to prison for being gay
Sir Bradley Wiggins removes his silver medal after the podium ceremony for the men’s 4,000m team pursuit in Glasgow yesterday
Commonwealth games Disappointment for Sir Bradley in team pursuit final as England are forced to settle for silver
Alistair Brownlee (right) celebrates with his gold medal after winning the men’s triathlon alongside brother Jonny (left), who got silver
England's Jodie Stimpson won the women’s triathlon in the morning
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

SQL Report Analyst (SSRS, CA, SQL 2012)

£30000 - £38500 Per Annum + 25 days holiday, pension, subsidised restaurant: C...

Application Support Analyst (SQL, Incident Management, SLAs)

£34000 - £37000 Per Annum + excellent benefits: Clearwater People Solutions Lt...

Embedded Software / Firmware Engineer

£40000 - £45000 per annum + Pension, Holiday, Flexi-time: Progressive Recruitm...

Developer - WinForms, C#

£280 - £320 per day: Progressive Recruitment: C#, WinForms, Desktop Developmen...

Day In a Page

Backhanders, bribery and abuses of power have soared in China as economy surges

Bribery and abuses of power soar in China

The bribery is fuelled by the surge in China's economy but the rules of corruption are subtle and unspoken, finds Evan Osnos, as he learns the dark arts from a master
Commonwealth Games 2014: Highland terriers stole the show at the opening ceremony

Highland terriers steal the show at opening ceremony

Gillian Orr explores why a dog loved by film stars and presidents is finally having its day
German art world rocked as artists use renowned fat sculpture to distil schnapps

Brewing the fat from artwork angers widow of sculptor

Part of Joseph Beuys' 1982 sculpture 'Fettecke' used to distil schnapps
BBC's The Secret History of Our Streets reveals a fascinating window into Britain's past

BBC takes viewers back down memory lane

The Secret History of Our Streets, which returns with three films looking at Scottish streets, is the inverse of Benefits Street - delivering warmth instead of cynicism
Joe, film review: Nicolas Cage delivers an astonishing performance in low budget drama

Nicolas Cage shines in low-budget drama Joe

Cage plays an ex-con in David Gordon Green's independent drama, which has been adapted from a novel by Larry Brown
How to make your own gourmet ice lollies, granitas, slushy cocktails and frozen yoghurt

Make your own ice lollies and frozen yoghurt

Think outside the cool box for this summer's tempting frozen treats
Ford Fiesta is UK's most popular car of all-time, with sales topping 4.1 million since 1976

Fiesta is UK's most popular car of all-time

Sales have topped 4.1 million since 1976. To celebrate this milestone, four Independent writers recall their Fiestas with pride
10 best reed diffusers

Heaven scent: 10 best reed diffusers

Keep your rooms smelling summery and fresh with one of these subtle but distinctive home fragrances that’ll last you months
Commonwealth Games 2014: Female boxers set to compete for first time

Female boxers set to compete at Commonwealth Games for first time

There’s no favourites and with no headguards anything could happen
Five things we’ve learned so far about Manchester United under Louis van Gaal

Five things we’ve learned so far about United under Van Gaal

It’s impossible to avoid the impression that the Dutch manager is playing to the gallery a little
Screwing your way to the top? Good for Lana Del Rey for helping kill that myth

Screwing your way to the top?

Good for Lana Del Rey for helping kill that myth, says Grace Dent
Will the young Britons fighting in Syria be allowed to return home and resume their lives?

Will Britons fighting in Syria be able to resume their lives?

Tony Blair's Terrorism Act 2006 has made it an offence to take part in military action abroad with a "political, ideological, religious or racial motive"
Beyoncé poses as Rosie the Riveter, the wartime poster girl who became a feminist pin-up

Beyoncé poses as Rosie the Riveter

The wartime poster girl became the ultimate American symbol of female empowerment
The quest to find the perfect pair of earphones: Are custom, 3D printed earbuds the solution?

The quest to find the perfect pair of earphones

Earphones don't fit properly, offer mediocre audio quality and can even be painful. So the quest to design the perfect pair is music to Seth Stevenson's ears
US Army's shooting star: Lt-Col Steven Cole is the man Hollywood calls when it wants to borrow a tank or check a military uniform

Meet the US Army's shooting star

Lt-Col Steven Cole is the man Hollywood calls when it wants to borrow a tank or check a military uniform