The next phase -- underwater search -- is going to be really hard
Over the past week, four satellites have reported sighting a debris field:
1. Photos taken on March 16th by an Australian satellite and released by an American company showed two large objects about 2,500 km (1,550 mi) southwest of Perth, Australia.
2. Photos taken on March 18th by a Chinese satellite showed one large object (22.5m x 13m) about 120 km (75 mi) from the Australian debris.
3. Photos taken on March 23rd by a French satellite showed 122 objects up to 75 feet long at a place about 120 km from the Australian debris.
4. Photos taken on March 24th by a Thai satellite showed up to 300 objects up to 52 feet long at a site about 200 km (125 mi) south of the French debris.
During a search like this, there will be a tendency for each satellite control team to try to confirm the other teams' observations first, before looking at new patches of the ocean. One hopes that all these teams are not simply chasing down the debris field that was sighted first, but are looking elsewhere, too. Many commentators have said that debris tends to collect here in the south Indian Ocean. Perhaps we should be asking why there have not been more satellite reports of debris.
In due course, some of this debris will be picked up. Assuming it is from MH370, the underwater recovery phase will begin. Even if some pieces were picked up and positively identified today, time has run out for the ELTs (Emergency Location Transmitters). It has been more than 20 days since they were activated; 15 or fewer days remain before the batteries die. There is no prospect that an underwater listening device will pick up the signal. The current location(s) of the debris field(s) are now so far from their locations when the satellite images were made, and they in turn are so far from the original ditching site, that a lengthy search pattern will have to be used.
The reality is that the ocean floor is going to have to be searched visually or, at the very least, with underwater radar. The travel speed of these devices is miniscule compared to the size of the search area. By way of comparison, consider the length of time it took to find the remains of the "Titanic" and remember that she sank only ten miles from the ship "Carpathia", whose position was known with much greater precision than the point of impact of MH370.
The cost in time and money of finding MH370 on the ocean floor may be too much to pay. It may be that the authorities will have to make a tough decision: not to search for the wreckage.