“They picked that (frequency) so there wouldn't be false alarms from other things in the ocean,” he said.
But after weeks of false alarms, officials were careful Sunday not to overplay the development.
“We are hopeful but by no means certain,” Australian Prime Minister Tony Abbott said of the detection of the signals.
“This is the most difficult search in human history. We need to be very careful about coming to hard and fast conclusions too soon,” Abbott told reporters during a visit to Japan.
Houston, the search coordinator, conceded that his organization first heard about the initial signal China had detected when it was reported by a Chinese journalist aboard the Haixun 01.
He said that at “almost the same time” he was informed of the development by the Chinese government.
The agency was formally told about the second Chinese detection on Saturday “in absolutely the normal way,” he said.
“China is sharing everything that is relevant to this search. Everything,” Houston said.
Still, the search agency will be adding a Chinese-speaking liaison officer “to make sure nothing falls through the cracks,” he said.
