Earth Observatory Blog

Submitted on 23 Mar 2017 by:

The tectonically sleepy, yet very populated island of Bali was shaken on Wednesday morning (22 March 2017) by a magnitude-5.5 earthquake. Located 2 kilometres (km) northeast of Banjar Pasekan in southeastern Bali, the morning quake shook the area. But, because of its 118 km-depth, it did not cause major damage or any casualties.

Director of the Earth Observatory of Singapore, Professor Kerry Sieh, who has studied the mega-thrust fault off of the western side of Sumatra and down through Java and Bali, suggests that yesterday’s moderate earthquake is a reminder to us that even though the area has been dormant for the past several hundred years, it has the potential to release a large earthquake, or even a series of large quakes, of about magnitude-8.5 to 9.0 in the...

Submitted on 11 Mar 2017 by:

The devastating 2011 Tohoku earthquake in northeastern Japan was a record-breaker on many levels. The magnitude-9.0 quake was Japan’s largest recorded and the world’s fourth biggest earthquake since 1900. Most terribly, it unleashed a 39-metre high tsunami, killing almost 16,000 people and causing a nuclear meltdown at Fukushima Daiichi Nuclear Power Plant.

The earthquake had effects on a global scale. Seismic waves caused icebergs to break off in Antarctica, water in Norwegian fjords to splash back and forth, and wreckage from the tsunami washed up along the North American coastline. Another global consequence? The quake shortened Earth’s day by 1.8 microseconds (µs) and shifted its figure axis by 17 centimetres (cm). 

Just to clear things up, our planet...

Submitted on 01 Mar 2017 by:
Results from the MEGA-TERA expedition point to a new fault system that may be a sign of the Indian and Australian plates breaking up 

On 11 April 2012, a strong quake ruptured in the Wharton Basin of the Indian Ocean, west of Sumatra. Remembering the devastating 2004 tsunami, residents near the shore immediately sought high ground. Thankfully this earthquake was different. At a staggering 8.6-magnitude, it produced a maximum wave height of about one metre.

Why didn’t this earthquake produce a tsunami? Instead of being a thrust earthquake, where plates lurch up and down and displace water, the 2012 quake was a strike-slip, with the crust moving horizontally.

Wharton Basin Earthquake: Record-Smashing

The previous record holder for the largest strike-slip...