Here’s a good-news PR story in the making: suppose information provided by seismic surveys could save 300,000 lives?

That’s the number of lives lost in the 2004 tsunami that ravaged much of the Indian Ocean coastline. The numerous islands that make up Indonesia were hit particularly hard, and that country’s government decided to enlist the help of the worldwide scientific community to find ways of preventing these disasters in the future by building a greater understanding of the causes of earthquakes and finding ways to predict future events. It also enlisted the help of the Institute de Physique du Globe (IPG) in Paris, which formed the Sumatra-Andaman Great Earthquake Research group. The group proposed a set of seven marine experiments including side-scan sonar bathymetry, ocean-bottom seismic monitoring, and marine streamer seismic acquisition.

But this is not your normal streamer program. The targets of interest lie several miles underground, often at great water depths. WesternGeco was enlisted in 2005 to conduct a Q-Marine survey over part of the area, and more recently CGGVeritas acquired a survey deploying Sercel Sentinel solid streamers in a new configuration from its Geowave Champion.

The project was dubbed Tsunami Investigation — Deep Evaluation Seismic (TIDES). And deep pretty well sums it up. According to Satish Singh of the IPG, the new survey required some ground-breaking technology.

“With an earthquake, you have to know how it initiates deep down and how it arrives on the seafloor,” Singh said. “For this new survey, we needed top-level technology and had to create something new. CGGVeritas was a natural choice.

“We needed to image 18 to 21 miles (30 to 35 km) deep into the earth in 3 miles (5 km) of water, while still obtaining shallow resolution to have a complete understanding of the phenomena. We’re imaging up to 27 miles (45 km) using very long streamers, 9 miles (15 km). They’re the longest ever used, pushing the technical limits. The solid streamers used on this survey have the tensional strength and power transmission properties to achieve this record-breaking length. ”

Acquisition ended in late May 2009, and preliminary results are expected within six months.

The primary goal of the more recent survey is to evaluate an area north of Java that seems to be the next likely spot for a major earthquake. After the quake that spawned the ’04 tsunami, there was another quake in 2005 and yet another in 2007, but the geographical gap between the second and third quakes is quite large, leading to speculation that this might be the site of the next major event.

Singh said that the plates at these depths exhibit two basic kinds of behavior — either they slip against each other, causing no significant tectonic problems, or they become locked together and then break apart, causing a major tremor. He added that a quake in the study region could register as high as 9 on the Richter scale. The 2004 quake was 9.2.

Results from the CGGVeritas survey will be used in conjunction with previous surveys in the region, including the WesternGeco survey and other information.

The contractors are able to bring a new perspective to the project because of the vast amounts of technology they have developed over the years to image hard-to-see oil and gas fields. According to Stephan Midenet, sales & marketing manager, Asia Pacific region, CGGVeritas, “CGGVeritas proprietary technologies that will be used for this survey allow us to generate a clear picture of the lithospheric plate boundaries and support a deeper understanding of the distribution and geometry of faulting and seafloor displacement, all of which are key to understanding the mechanics of tsunami generation.We believe that the innovative configuration of both sources and streamers, along with our processing capabilities using our proprietary geovation software, will completely address the imaging requirements.”

While no one expects the exact timing or location of an earthquake to be predicted, building a better understanding of earthquake behavior might lead to a better warning system. “The events of 2004 were so devastating because they were completely without warning,” said Midenet.

All of this makes the project very important for CGGVeritas. There are no plans to find any direct commercial use for these data. The survey is strictly intended to further the science of earthquake and tsunami understanding and ultimately help the people living in the area. At the same time, it allows CGGVeritas to develop and deliver continued advances in subsurface images, and that will definitely be of interest for both the scientific and oil and gas communities, he said.

“We’ve been working in this area for 60 years,” said Midenet. “We are pleased to have the opportunity and believe it is our responsibility to take part in this project. Through the deployment of our highest technology we hope that it can make a positive difference to the science of geophysics and to the people of the region."

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