Almost two years after "earthquake diplomacy" strengthened relations between traditional rivals Greece and Turkey, the neighbours pledged increased cooperation to study the killer fault line that links them.
Cross-border fault
The North Anatolian fault that stretches across parts of northwestern Turkey and into the Aegean Sea toward mainland Greece produced the deadly 7.4-richter earthquake in 1999 that killed more than 18,000 people around Istanbul. It most recently jolted the Greek island of Skyros with a 5.7-richter temblor that caused no injuries but inflicted widespread damage to buildings.
The joint project aims at pooling resources and sharing information that would provide more details of quake-prone areas to help governments use resources effectively, and city planners and architects to better calculate development risks before and after seismic activity.
Eleftheria Papadimitriou, an associate professor at Thessaloniki's Aristotle University department of geology, welcomed the venture as an extension of the unprecedented wave of sympathy and mutual aid following the 1999 quakes in Istanbul and another in Athens that was caused by a smaller fault system north of the city and left 143 people dead.
Seismic resistence
"The earthquake in 1999 prompted this cooperation. We are studying ways to make the two countries resistant to earthquakes," she said. "We want to gather more data so that precautionary measures can be taken."
"We are committed to open science collaborations and shared data policies," added Naci Gorur, an Istanbul Technical University researcher. "New observations can only be obtained by coordinating marine surveys of the sea floor."
Scientists from Italy, France and the United States also said they would join the project, with researchers from New York's Columbia University hoping to use their valuable sonar equipment to study undersea sections of the 1,500-kilometre-long fault, that runs through the Aegean and Turkey's Sea of Marmara.
"The Northern Anatolian Fault runs across national boundaries... the earth does not know about political boundaries," said Michael Purdy, head of Columbia University's Lamont-Doherty Earth Observatory that studies the risk earthquakes pose around the world. "So as earth scientists we have to work across boundaries."
Mapping the fault
"The sea floor maps, the sediment images and the cores will together form the most complete set of submarine geological information ever assembled for the northern Aegean and the Marmara seas," Gorur said.
The group of scientists met in Thessaloniki from July 30 to August 1 to coordinate their efforts and plan necessary research before coming to Athens to officially announce their collaboration. They included researchers from Athens University, Athens' National Observatory, Bogazici University in Turkey and Italy's University of Bologna. Also joining the study will be engineers, urban planners, economists and public health experts.
Scientists hope to use the Maurice Ewing, a research vessel operated by Columbia, on the Anatolian fault. The ship has ultra-sensitive sonar and imaging equipment that for the first time may be used to create a detailed undersea map of the fault.
Detailed mapping would locate areas under strain and at risk of breaking.
The vessel already has carried out experiments and mapped parts of the crust at the Gulf of Corinth.
Parallels with San Andreas
American scientists have a particular interest in North Anatolia's underwater strike-slip fault because of its similarity with the San Andreas Fault in California, in which the two plates slide past one another.
Researchers also find the submarine fault interesting because the history of past seismic activity remains embedded in the sea floor.
The fault lines "represent a significant risk to our people, but they also form a unique natural laboratory in which we can study ways to reduce that risk," Gorur said.
Faults on land, like the San Andreas, tend to lose the physical record of earthquakes through erosion. But the Anatolian's underwater sections in the Sea of Marmara and the Aegean retain clues to hundreds of years of seismic activity.
Footprint in the sand
"When there's an earthquake it leaves a record in that mud and if you can use sonar to look at that mud, you're looking at a... 'tape recorder' of earthquake activity," Purdy said.
Such a historical record is very valuable to seismologists to understand long-term patterns. For example, over the past century, earthquakes have progressed westward along the fault toward mainland Greece.
Researchers also said their plans include creating three-dimensional models, identifying structures in the crust that caused quakes in the past and understanding the nature of the system's western termination against the Greek mainland.
Gorur also suggested an internet-based northern Aegean and Marmara earthquake information network that "could serve as an electronic village for international research collaboration."
While the group is not trying to learn how to predict precisely when an earthquake is going to occur, they "believe that our skill to define earthquake risk is really improving," according to Purdy.
Gorur said that at the scientists' next meeting, they would begin "a much more detailed study of the outstanding research issues and we will continue to make plans for the surveys that will be needed."
Project funding will also be a topic of discussion at the next meeting, planned for November in Istanbul.
