Nav: Home

International ocean drilling expedition to understand causes of the Indian Ocean 2004 earthquake

August 08, 2016

The devastating earthquake that struck North Sumatra and the Andaman and Nicobar Islands on Boxing Day (26 December) in 2004 caused a tsunami that inundated coastal communities around the Indian Ocean, killing over 250,000 people in 14 countries. That earthquake was caused by a slip on a subduction zone plate boundary fault beneath the eastern Indian Ocean.

Now, over the coming weeks, a team of international researchers are returning to offshore Sumatra to collect marine sediments, rocks and fluids from this particular zone for the first time to gain a better understanding of the materials and to collect data for predicting how they behave in fault zones to generate large earthquakes.

Throughout August and September the researchers, including experts from Ocean and Earth Science at the University of Southampton will spend two months on board the drilling vessel JOIDES Resolution as part of the International Ocean Discovery Programme (IODP). The Expedition, number 362 of the IODP, involves 33 scientists and two educators from 13 countries including Professors Lisa McNeill and Tim Henstock from the University of Southampton. Professor McNeill is one of the Expedition leaders along with Associate Professor Brandon Dugan of the Colorado School of Mines and Dr Katerina Petronotis of the IODP.

"We are very excited that the project is about to start as it has taken many years of preparation and the dedication of a large team of scientists from around the world," said Professor McNeill. "We have an excellent team onboard and we hope the results will help us understand what controls the size of the very largest earthquakes on Earth, particularly following the enormous numbers of casualties due to subduction earthquakes and tsunamis in the last 10-15 years.

"The Boxing Day earthquake of 2004 and the Japan Tohoku-oki earthquake in 2011 both ruptured to much shallower depths than expected, producing very large earthquakes and tsunami, and prompting a re-evaluation of earthquake slip potential and of the properties of shallow subduction faults," Professor McNeill continued. "Subsequent large magnitude earthquakes have struck this margin since 2004, including unusually large earthquakes in the Indian plate offshore North Sumatra in 2012. Therefore developing a better understanding of earthquake and tsunami behavior and potential is a priority for local communities, for the wider Indian Ocean, and for related subduction zones."

Professor McNeill explained that the North Sumatran subduction margin has an unusual structure and morphology that is likely influenced by the properties of the sediments and rocks forming the margin.

"Although our understanding of this margin's structure and development has increased enormously since 2004 due to marine geophysical data collection, as yet very little is known of the properties of the materials that make up this subduction zone," she continued. "This project will investigate how materials coming into the system drive shallow earthquake rupture and influence the shape of the continental margin. Our ultimate goal is to understand the hazard potential for this margin, and eventually others with similar material properties and margin morphology.

"This ocean drilling expedition will for the first time drill scientific boreholes within the sediments entering this subduction zone, including the layer of sediment that eventually develops into the earthquake-generating fault," Professor Henstock explained. "We know the sediments are of deep sea and terrestrial origin, including those eroded from the high Himalayas and transported thousands of kilometres into the Bay of Bengal and eastern Indian Ocean. But we do not know how the sediments change as they become physically and chemically altered as the sediment section builds up to 4-5 km thickness before reaching the subduction zone.

"Burial and increased temperatures also affect fluids within the sediment pile, and these are very important for earthquake fault behavior," Professor Henstock concluded. "Sampling and measuring the properties of the materials in situ and then extrapolating their properties to greater burial depths using modeling techniques and lab experiments will be important goals of this project."

The vessel JOIDES Resolution is operated by the Science Operator based at Texas A&M University (USA) on behalf of the US National Science Foundation. IODP and its predecessors have led scientific ocean drilling worldwide since 1968. Currently, IODP has 26 international partners: USA, Australia, Austria, Belgium, Brazil, Canada, P.R. China, Denmark, Finland, France, Germany, India, Ireland, Israel, Italy, Japan, Korea, Netherlands, New Zealand, Norway, Poland, Portugal, Spain, Sweden, Switzerland, and the United Kingdom.
Notes to editors:

Through world-leading research and enterprise activities, the University of Southampton connects with businesses to create real-world solutions to global issues. Through its educational offering, it works with partners around the world to offer relevant, flexible education, which trains students for jobs not even thought of. This connectivity is what sets Southampton apart from the rest; we make connections and change the world.

University of Southampton

Related Earthquake Articles:

Earthquake symmetry
A recent study investigated around 100,000 localized seismic events to search for patterns in the data.
Crowdsourcing speeds up earthquake monitoring
Data produced by Internet users can help to speed up the detection of earthquakes.
Geophysics: A surprising, cascading earthquake
The Kaikoura earthquake in New Zealand in 2016 caused widespread damage.
How fluid viscosity affects earthquake intensity
A young researcher at EPFL has demonstrated that the viscosity of fluids present in faults has a direct effect on the intensity of earthquakes.
Earthquake in super slo-mo
A big earthquake occurred south of Istanbul in the summer of 2016, but it was so slow that nobody noticed.
A milestone for forecasting earthquake hazards
In a new study in Science Advances, researchers report that their physics-based model of California earthquake hazards replicated estimates from the state's leading statistical model.
Mw 5.4 Pohang earthquake tied to geothermal activity?
The Mw 5.4 Pohang earthquake that occurred near a geothermal site in South Korea last year was likely triggered by fluid injection at the geothermal plant, two separate reports conclude.
Seismologists introduce new measure of earthquake ruptures
A team of seismologists has developed a new measurement of seismic energy release that can be applied to large earthquakes.
Residual strain despite mega earthquake
On Christmas Day 2016, the earth trembled in southern Chile.
The losses that come after the earthquake: Devastating and costly
The study, titled, 'Losses Associated with Secondary Effects in Earthquakes,' published by Frontiers in Built Environmen, looks at the devastation resulting from secondary disasters, such as tsunamis, liquefaction of sediments, fires, landslides, and flooding that occurred during 100 key earthquakes that occurred from 1900 to the present.
More Earthquake News and Earthquake Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at