UU scientists issue Indonesia earthquake warning

March 16, 2005

The stresses in the earth's crust which have resulted from the Sumatra-Andaman earthquake have significantly increased the risk of another large earthquake in the already-devastated Indonesian island of Sumatra, according to new research findings by scientists from the University of Ulster's School of Environmental Sciences.

According to their calculations, published in this week's edition of leading scientific journal Nature, the Christmas 2004 earthquake which generated the massive tsunami which hit Indonesia, Thailand, India and Sri Lanka and killed 300,000 people, has significantly increased the stress on two other fault zones in the area - one of them running directly under the city of Banda Aceh which was so badly effected by the Boxing day event - the other under the sea off the west coast of Sumatra.

The latter could generate another tsunami.

The University of Ulster team, led by Professor John McCloskey of the School of Environmental Sciences, analysed data from the 2004 Sumatra-Andaman earthquake to look at its impact on other faults in the area. The analysis process is described in the Notes For Editors below.

The analysis found two zones showing significantly increased levels of stress - one in the Sunda trench, a 50km-long underwater zone off the northern tip of Sumatra, and the other in the Sumatra fault, which runs for 300km along the centre of the island of Sumatra, ending under the city of Banda Aceh.

"Our results show a stress increase of up to 5 bars in the Sunda trench next to the rupture zone, and a strong positive loading of 9 bars for 300km of the Sumatra fault," said Professor McCloskey.

These levels of seismic stress indicate significantly increased risk of an earthquake, said Professor McCloskey. Previous work on the earthquakes on the Sunda trench show that it has produced large (up to M8.5) earthquakes and two in 1833 and 1861 produced fatal tsunamis.

An earthquake in the Sumatra fault might be expected to have a magnitude up to about M7.5, but because it is not underwater, would not cause a tsunami.

"We have all heard that lightning does not strike twice in the same place -but earthquakes do' he said. 'One of the strongest observations in seismology is that earthquakes cluster in space and time. Where you have one earthquake you are likely to have others."

How sure are we that another event will occur? "We do know that the increase in stress is real and that ultimately it is stress that causes earthquakes. This much is sure. There is a strong relationship between these results and the probability of another earthquake in Indonesia.

"Unfortunately, we do not yet know how this relationship works out in detail. The mapping is certainly not one-to-one.' said Professor McCloskey.

But we can learn a lot from other examples, he said.

"The recent destructive earthquake at Izmit in Turkey (magnitude 7.4) was probably triggered by stress increases of less than two bars over an area of about 50km. It in turn triggered another earthquake (magnitude 7.1) at Düzce, just three months later. Again, the stresses were on the order of a couple of bars. Our calculations show that the stresses on the Sumatra fault increase to about 9 bars near the city of Banda Aceh. The stress remains positive for about 300 km to the south. These stresses are big and extensive," he said.

In the wake of their findings, the UU team have added their voices to the calls for a tsunami early-warning system to be put in place in the Indian Ocean as a matter of urgency. "The loss of much of the life in the December earthquake was avoidable. The science is well understood, the warning systems are in place in the Pacific region The levels of preparedness, public awareness and education in this region are high and do save lives. Unfortunately the people of the Indian Ocean region have neither benefited from this knowledge nor from the available technology," said Professor McCloskey.

"Our results indicate unambiguously that there is a real danger of another earthquake in the region. It is vital that disaster fatigue does not delay the implementation of the Circum Indian Ocean Tsunami Warning System."

Recent information indicates that the German government has allocated €40m to putting this system in place.
-end-


University of Ulster

Related Stress Articles from Brightsurf:

Stress-free gel
Researchers at The University of Tokyo studied a new mechanism of gelation using colloidal particles.

Early life stress is associated with youth-onset depression for some types of stress but not others
Examining the association between eight different types of early life stress (ELS) and youth-onset depression, a study in JAACAP, published by Elsevier, reports that individuals exposed to ELS were more likely to develop a major depressive disorder (MDD) in childhood or adolescence than individuals who had not been exposed to ELS.

Red light for stress
Researchers from the Institute of Industrial Science at The University of Tokyo have created a biphasic luminescent material that changes color when exposed to mechanical stress.

How do our cells respond to stress?
Molecular biologists reverse-engineer a complex cellular structure that is associated with neurodegenerative diseases such as ALS

How stress remodels the brain
Stress restructures the brain by halting the production of crucial ion channel proteins, according to research in mice recently published in JNeurosci.

Why stress doesn't always cause depression
Rats susceptible to anhedonia, a core symptom of depression, possess more serotonin neurons after being exposed to chronic stress, but the effect can be reversed through amygdala activation, according to new research in JNeurosci.

How plants handle stress
Plants get stressed too. Drought or too much salt disrupt their physiology.

Stress in the powerhouse of the cell
University of Freiburg researchers discover a new principle -- how cells protect themselves from mitochondrial defects.

Measuring stress around cells
Tissues and organs in the human body are shaped through forces generated by cells, that push and pull, to ''sculpt'' biological structures.

Cellular stress at the movies
For the first time, biological imaging experts have used a custom fluorescence microscope and a novel antibody tagging tool to watch living cells undergoing stress.

Read More: Stress News and Stress Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.