Earth Observatory Blog

Submitted on 08 Mar 2018 by:

The highly active Sumatran Subduction Zone has produced more than four great earthquakes in the last decade. The first of these was the giant Mw 9.2 Sumatra-Andaman earthquake that ruptured on 26 December 2004. This devastating event was followed by three others – the Mw 8.6 Nias-Simeulue quake in 2005, the Mw 8.4 Bengkulu earthquakes in 2007, and the Mw 7.7 Mentawai tsunami-earthquake in 2010.

In order to understand why so many great earthquakes originate from this region, we have to measure the strength of the rocks in the earth’s lower crust and upper mantle. Our new research, published today on 8 March 2018 in Nature Communications, highlights a ground-breaking new approach to how the strength of these rocks...

Submitted on 16 Aug 2017 by:

In 2013 and 2015, Singapore suffered from extreme haze. Channel NewsAsia sat down with two experts to find out more about Singapore's haze prospects for 2017.

Assistant Professor Mikinori Kuwata, a Principal Investigator at the Earth Observatory of Singapore, discussed Singapore's haze situation with Vivian Claire Liew, the CEO of the social enterprise PhilanthropyWorks. Asst. Prof Kuwata explained how a combination of factors - both human and natural - will influence the prevalence of haze in Singapore.

Available online from August 14 2017 at 10pm, the video commentary can be viewed here.

Submitted on 05 May 2017 by:

Different rainforest trees grow on an island called Siberut; one of four big islands of the Mentawai Archipelago located off the west coast of Sumatra, Indonesia. Katuka is what Mentawaians call one family of these dipterocarp trees. These trees have very hard wood and are widely used for construction and crafting.

I want to tell you the story of one katuka tree in particular. This 400-year-old tree will soon surrender its life to serve the needs of the people. 

A Giant Falls

As the sun rises over Siberut Island, a Mentawaian called Aman Ani and his fellow villagers sharpen their axes. They prepare their meals, as well as an offering for the forest spirits. Later, they sit quietly in a motorised canoe as they cruise upstream. Some of them are...

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 18 Dec 2016 by:

At just past five o'clock in the morning on 7 December 2016, a damaging earthquake struck Aceh, Indonesia. Damage was most severe in Pidie Jaya and neighbouring Pidie and Biruen Regencies, located east of the provincial capital of Banda Aceh. Extensive building damage tragically led to the loss of more than 100 lives. More than 80,000 people are displaced, unable to return because of destroyed or damaged buildings. People fear returning to their homes and community buildings because the...

Submitted on 09 Dec 2016 by:

The previous post focused mainly on the 1991 Pinatubo eruption and how it affected humans and history (scientific in this case). Today’s post will cover a historic eruption that changed the course of history on one Indonesian island, and around the world. No, it isn’t the 1815 Tambora eruption. Although that was an amazing eruption with respect to global impacts, today we will cover the lesser known 1257 Samalas eruption.

1257 Samalas – Lombok, Indonesia


Samalas is located on the island of Lombok in Indonesia. Pyroclastic flows descended from the summit to the southeast, southwest, and nearly wiped out the north coast. Ash deposits provide evidence for an ash plume reaching between 39 and 43 kilometres (km) in altitude. The high altitudes...

Submitted on 20 Sep 2016 by:

Edible vegetable oil, produced from oil palm and soybeans, is a key ingredient in junk food like chips and ice cream. Although these foods have little to no nutritional value, global consumption is on the rise, resulting in an increase in demand for vegetable oil. This has become a serious issue because large areas of land in Southeast Asia and South America have to be cleared to make way for oil palm and soybean crops. 

A study, led by Assistant Professor Janice Lee of the Asian School of the Environment, has found that more forests will be cleared by the year 2050 as a result of the increased demand in vegetable oil. Along with this deforestation, valuable biodiversity will be lost in Southeast Asia, and sequestered carbon (carbon stored in plants, soils, and geologic...

Submitted on 19 Sep 2016 by:

The MIRAGE research team returned from their month-long expedition, almost two months ago on 30 July 2016, with a great deal of data that was collected directly from the seafloor of the Wharton Basin in the Indian Ocean.

Although most of the data are still being analysed, there is one finding that Professor Satish Singh is happy to share with us now.

“On this expedition, we were successful in fully mapping a large seamount,” said Prof Singh, a visiting professor at the Earth Observatory of Singapore from the Institut de Physique du Globe de Paris. “It is always exciting to see an underwater...

Submitted on 26 Aug 2016 by:

Today marks the anniversary of the 26-27 August 1883 eruption of Krakatau Volcano, Indonesia 

The 1883 eruption of Krakatau (also widely known as Krakatoa) volcano in Indonesia has captured the imagination of many people – from the first Malay account of the eruption by Muhammad Saleh (Syair Lampung Karam – published in Singapore) to the 1969 film Krakatoa, East of Java, starring Maximillian Schnell.

And how not? The eruption is remarkable in many ways. Early signs of unrest began in May 1883 and increased in intensity until the climactic eruption commenced on 26 August, with a large ash plume extending upwards of 27 kilometres (km) into the sky and the generation of a small tsunami.

From 5.30 am to 10.41 am (local time) on 27 August, the eruption culminated in...

Submitted on 30 Jul 2016 by:

It has been almost a month since we left the port of Colombo to make our way to the Wharton Basin, a place so remote that I can count on one hand the number of container ships and fishing boats I saw during our three weeks there.

In that time, we surveyed 90,000 square kilometres (km2) of seafloor, an area roughly the size of Ireland, acquiring bathymetry, gravity and magnetic data, sub-bottom profiles, and several dozen metres of sediments taken during two marathon coring operations.

The last time a research vessel was in the Wharton Basin, during the MEGA-TERA cruise of 2015, 7,500 km2of bathymetry was acquired, plus another 950 kilometres (km) of high-resolution seismic reflection data. By any measure, the MIRAGE has added enormously to the...