The new underwater search for MH370 will focus on a 60,000 square kilometre area - compared to the 860km searched below the surface so far.
The new phase will have two elements - firstly the mapping of the sea floor, followed by a comprehensive search.
The mapping will take around three months to complete, Australian Deputy Prime Minister Warren Truss said, but will give "crucial" information for later search efforts, due to start in August.
More top news
The Government said Judge Munby's plan to tag adults thought to be at risk of joining Islamic State was "novel".
July has been a month of extremes - a heatwave brought temperatures up to 37C to begin with and ended on a low last night.
Frustrated NatWest customers have taken to Twitter after they were unable to login to their online banking today.