World Bulletin / News Desk
Two massive quakes off Indonesia's Sumatra island in April showed something scientists have long been trying to prove - they can trigger a swarm of more tremors around the globe.
The latest findings could eventually help efforts to predict some earthquakes.
Over the six days after the quakes hit on April 11, the number of tremors of magnitude greater than 5.5 jumped nearly fivefold globally, lead author Fred Pollitz of the U.S. Geological Survey and colleagues found in a study published in the journal Nature on Thursday.
"This is the first time that we've seen these remote aftershocks at this magnitude and to this extent," said Kerry Sieh, director of the Earth Observatory of Singapore, author of a number of studies on earthquake hazards in the Sumatra region.
The first quake on April 11 was 8.7 magnitude, nearly as large as the one which triggered a massive tsunami and nuclear disaster in eastern Japan just over a year earlier.
The second one was also huge, at 8.2. Both occurred under the Indian Ocean several hundred kilometres west of Sumatra, in a zone where the Indo-Australian tectonic plate is slowly tearing itself apart.
"The Pollitz paper shows that you can get significant, potentially destructive-sized earthquakes thousands of kilometres away from a mid-8 earthquake," Sieh, who was not part of the current study, told Reuters.
Pollitz and colleagues examined a range of seismic data, with particular focus on so-called Love-wave radiation, surface waves that move in a snake-like motion and can travel right across the globe.
All the global aftershocks were located right along the four main lines of the Love-wave radiation that began at the epicentre of the main April 11 quake.
In future, studying such data could improve calculations about the increased likelihood of earthquakes after a major quake, said Sieh.
Scientists rushed to analyse the April quakes because they occurred in one of the world's most seismically active zones.
The 2012 quakes are believed by most seismologists to be the largest strike-slip tremors ever recorded, and all the more noteable for not triggering a large tsunami.
Strike-slip faults slide horizontally when they fracture, rather than triggering a sudden uplift of the sea floor like the 9.2 quake that struck off nearby Aceh province in northern Sumatra in December 2004, or last year's 9.0 quake off Japan. Both triggered deadly tsunamis.
Public shuttle was displayed during international conference in Turkey
The Transiting Exoplanet Survey Satellite, or TESS, is scheduled to launch Monday at 6:32 pm (2232 GMT) atop a SpaceX Falcon 9 rocket from Cape Canaveral, Florida.
Telegram blocked when app makers decline to provide encryption key to Federal Security Service
The company will tell users if their information were improperly shared with Cambridge Analytica
Fund to support scientists in finding solutions to challenges in Muslim World, Islamic Development Bank says in Tunis
Speaking to the news site Vox, Zuckerberg defended the company's business model and shot back at criticism of the social networking giant from Apple CEO Tim Cook last week.
A Tesla Model X collided with a highway barrier near the town of Mountain View in California on March 23, catching fire before it was struck by two other cars.
Company establishing two new teams -- Experiences and Devices, and Cloud and AI
The updates include improved access to Facebook's user settings and tools to easily search for, download and delete personal data stored by Facebook.
Social network giant has lost more than $100B in value loss since last week
Qantas on Saturday launched the first non-stop passenger service linking Australia and Europe, with a Boeing 787 Dreamliner departing Perth for London on one of the longest flights in the world.
Lowest levels of wintertime sea ice on record occurred during past four years
Three veteran space fliers launch successfully to join crew on space station in two days
The so-called Langlands programme dates back to 1967, when the then-associate professor at Princeton University wrote a letter to renowned French mathematician Andre Weil outlining his new theory.
Calls for investigations came on both sides of the Atlantic after Facebook responded to explosive reports of misuse of its data by suspending the account of Cambridge Analytica, a British firm hired by Trump's 2016 campaign.
New research says reducing carbon emissions sooner could prevent 153 million premature deaths globally