Canie, before the 1999 quakes the location of the active strands of the North Anatolian fault (NAF) was poorly known in Marmara Sea, even adjacent to Istanbul. It was a bit of a cottage industry to compile different published models for faulting there for use in proposals: HW did one of these. The Turks collected some seismic reflection in 1997 and a little more in 1999, and Okay et al 1999 and 2000 did a pretty good job on interpretation/models. Then, after the quake the French collected multibeam bathymetry over all of Marmara Sea except the shallow continental shelves (which are better done with a different system, and it takes longer). They also got a dense grid of deep crustal seismic reflection in the east. (All this sort of work is in collaboration with the Turks).

HW was a P.I. on a project with Italians and Turks that included high resolution bathymetry and seismic that showed position of NAF in the east in Izmit Bay/Gulf, and the extent of the seafloor part of the 1999 rupture.

The French multibeam bathy clearly shows the main active stand(s) of the northern NAF. They have since even dove on it with ROVs and submarine. They are talking about putting sea floor observatory (s). Lots of gas coming out of parts of the main fault. Maybe they will try and monitor this.

The seismic data we collected were much higher resolution than the deep French crustal data: we imaged stuff that simply can't be seen on theirs (while theirs provides information ours cannot). Our data are somewhat higher resolution than the 1997 Turkish data, and ours image much better on the shallow southern shelf.

There are still major uncertainties/controversies in Marmara Sea. There are still major controveries/uncertainties even right beneath Los Angeles.

Until 20 years ago, the blind thrusts around LA were not generally recognized, at least by the academics. Then, the southern California community went overboard with blind thrusts, until people like Tom Rockwell went "whoa, sorry, I did a 3D trench and that is a strike-slip fault". OK, I made up the quote, but something to that effect.

Sorlien, Broderick, Seeber et al have a submitted manuscript to JGR proposing an alternative model for faulting beneath southwest Los Angeles.

For Marmara Sea Turkey, there are still controversies on such things as the extent of the extension (stretching), whether slip on the north NAF near Istanbul is constant over time, the map pattern and activity of faults farther south, and the age of the sedimentary rocks and basins. We'll be working on this.
Chris