European and Asian scientists take to the sea to fathom the ‘2012 Great Earthquake’

European and Asian scientists take to the sea to fathom the ‘2012 Great Earthquake’

  • Press Release
28 Jun 2016

Joint News Release                                                                      

European and Asian scientists take to the sea to fathom the ‘2012 Great Earthquake’

Singaporean, French and Indonesian scientists will be heading into the Indian Ocean in July to investigate the cause of the largest intraplate earthquake ever recorded in an ocean.

Earth Observatory of Singapore, an institute of Nanyang Technological University, (EOS) scientists will be leading an international team to the Wharton Basin in the Indian Ocean, alongside researchers from the Institut de Physique du Globe de Paris (IPGP), France, and the Indonesian Institute of Sciences (LIPI).

The month-long expedition aims to fully understand the anatomy of the rupture patterns and faults of this magnitude-8.6 ‘intraplate’ earthquake which occurred on 11 April 2012 off the west coast of Sumatra. 

Relatively rare, an intraplate earthquake occurs in the interior of a tectonic plate (or massive irregular solid rock slabs), whereas the more common interplate earthquake occurs at the boundary between two tectonic plates.

The study also seeks to determine whether the recent large earthquakes at the Wharton Basin could herald the start of a new fault line, which happens only once every few million years.

Officially known as The MIRAGE (Marine Investigation of the Rupture Anatomy of the 2012 Great Earthquake) Expedition, it will be conducted on board the French research vessel R/V Marion Dufresne owned by the Institut Paul Emile Victor (IPEV).

The 110-metre oceanographic vessel will depart Colombo, Sri Lanka, on 1 July 2016 and make its way to the Wharton Basin located in the northeast quarter of the Indian Ocean.

Methods such as high resolution bathymetry and seismic reflections will be employed during this expedition to map the seabed and to discover the causes of both the recent and historic earthquakes in the area. 

The international scientific team consists of more than 20 scientists and students from all three research institutes, in addition to the crew on board the R/V Marion Dufresne.

Professor Paul Tapponnier, a world-renowned French earthquake expert from the Earth Observatory of Singapore (EOS) and one of the main scientists in the project, said, “With the Asian region a hotbed of tectonic activity, it is important for us to research and discover which earthquakes can lead to tsunamis and why, which can better prepare scientists and policymakers about the natural disasters that communities will be facing.”

“Just this year alone, the west coast of Sumatra has seen two large earthquakes with magnitudes measuring 6.6 and 7.8. They are so strong that the tremors are felt even in Singapore, where there is no known tectonic activity.” 

The team’s expedition to the Wharton Basin follows an earlier one in June last year to the Mentawai Gap, west of the city of Padang in Sumatra.

The expedition mapped out the section of the seabed that has not seen an earthquake in the last 200 years but is expected to rupture imminently, as adjoining sections along the same fault have already ruptured.

The data will allow scientists to get a better understanding of the targeted section of the 200-kilometre-long Mentawai Gap that is expected to lead to one or more major earthquakes.

Named the Mentawai Gap — Tsunami Earthquake Risk Assessment (MEGA-TERA), it was conducted on board the Schmidt Ocean Institute’s research vessel Falkor in June last year.

During the month-long voyage, the team of international scientists obtained 17,597 square km of high-resolution bathymetry along with 2,665 km of seismic reflection profiling.

The seabed imagery and data from Mentawai Gap will be compared to the Wharton Basin where the Great Earthquake happened, so as to analyse the differences between intraplate and interplate earthquakes and to see if there are any causal links between the two.

Professor Satish Singh, a visiting professor at EOS and a marine geophysicist from IPGP in France, will be leading this voyage.

“One of the biggest mysteries of the plate tectonics is ‘why and how a plate deforms away from the plate boundaries and produces giant earthquakes” said Prof Singh, who has been on over 26 ocean expeditions to understand underwater earthquakes.

“Like the last expedition, we will be using advanced deep-sea mapping technologies to study the seafloor at depths of 5,000 metres or more, so as to see if we can detect any discernible patterns or scars of previous earthquakes in the area, will give us a more accurate history of past earthquakes in the Wharton Basin.” 

Dr Nugroho Hananto is co-leading of the expedition from Research Centre for Geotechnology from LIPI.

All information and data obtained from the Indian ocean expeditions, such as the high-resolution maps of the ocean seabed, are shared publically with other scientists and research organisations around the world. 

***END***

Media contacts:

Shireen Federico

Communications Manager

Earth Observatory of Singapore

Nanyang Technological University

Tel: (65) 6908 2265

Email: shireenfederico@ntu.edu.sg

 

Lester Kok

Manager

Corporate Communications Office

Nanyang Technological University

Tel: 6790 6804; Mobile: 9741 5593

Email: lesterkok@ntu.edu.sg

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