Question about meaning of 'field' and 'established' in the context

Question

if a debris field is established. Is it talking about debris or just the area in which debris might be found?

The United States Navy is moving one of its high-tech Black Box detectors closer to the search area for a missing Malaysia Airlines plane in remote seas off the Australian coast, bolstering hopes wreckage of the plane may be found soon.Malaysian Airlines Flight MH370 vanished from civilian radar screens less than an hour after taking off from Kuala Lumpur with 239 people on board on a flight to Beijing on March 8.The so-called Towed Pinger Locator will be crucial in finding the black box of the missing jetliner if a debris field is established by an Australian-led international search team scouring an area in the southern Indian Ocean some 2,500 km (1,550 miles) southwest of Perth.

Answer 1

"Debris Field" is actually a set phrase meaning "an area in which debris is found".

Any area, non-dependent of locale, space, or contour, that contains the debris of wreckage, impact, sinking, or other material that once constituted a complete object. Debris fields can be found at the site of air crashes, water vessel sinking, explosions of buildings, collapses, and other events that render a whole entity into components, pieces, or other non-whole items.

So, to establish a debris field simply means: determining the area where wreckage will be found.