JD-EE, Thanks for your comments.
SaturnV, I have managed to dig out a video monitor shot taken in the FAB SAR control center at Recife. It shows that a grid search was undertaken in 2NM lanes 10NM either side of the track and for 55NM past the Last Known Position. With lanes 2NM apart, I expect the altitude flown was 1500 feet. However, it seems from other data in the pic that they finished up concentrating on unrelated debris found well to the SE of the track
The screen shot below has had some Lat / Long points marked, along with TASIL and the possible crash location.
Arslanian in his August 31 conversation with reporters said that the wreckage was in waters 3,000 to 3,500 meters deep.
I thought "they" hadn't been able to find any wreckage, so I think he is just making something up for the media - or maybe the media padded out the story.
The Wikipedia bathymetric profile gives a reasonable idea of the topography in this area, and your reference to the distorted height is good. Put it another way, the deepest valley is about 1.6km and the horizontal distance from top to bottom is 14km, giving a 6.57° average gradient. Bit much for most railways/railroads (1.5°)
, but not mountainous by any stretch of the imagination.
I will try and dig out a bathymetric profile for 3.2°N 30.9°W, I think something is available.
mm43