Transcript for America\'s New Frontier, segment 04 of 11

GLORIA is a sonar imaging instrument capable of mapping an area of sea floor the size of New Jersey and Delaware combined in just twenty-four hours. The GLORIA sonar system was developed from World War Two antisubmarine technology at the Institute of Oceanographic Sciences in Great Britain.

GLORIA is an acronym for Geological Long-Range Incline Asdig and what it does is to take advantage of the fact that sOunD is reflected more or less strongly according to the geology of the sea floor. So what we're doing is using sounds to make an image of sea floor geology. we send out a pulse of sound every thirty seconds, and this travels out to a distance of twenty-two-and-a-half kilometers each side of the ship, and during that time, we record the echoes, and they're plotted on the recorder as a line where the darkness or lightness is related to the strength of the echo, the strength of the echo being related to the geology. Then at the end of thirty seconds we send out another pulse, the ship having moved on a bit, and record the echoes in exactly the same way. So as time goes on, we get a series of lines placed side by side, and this builds up a picture in exactly the same way as a television raster, and the strength of the technique is that the geology dictates how strong the echoes are. For instance, rocks and mountain scarps will send back very strong echoes whereas a flat sedimented sea floor will send back a very much weaker echo, and so the patterns of the markings, the darkness on the records, will indicate the layout of the geology on the sea floor, and the idea is that the correlation that the pictorial view gives enables you to understand much more closely the processes going on in the geology.

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