US experts have upgraded the strength of the earthquake that rocked Japan last week from a magnitude of 8.9 to 9.0, making it the fourth largest in the world since 1900.
The US Geological Survey (USGS) said Japanese seismologists have also independently updated their estimate of the earthquake, which struck offshore in northern Japan on Friday unleashing a devastating tsunami.
“The USGS often updates an earthquake’s magnitude following the event,” the US-based centre said in a statement.
“Updates occur as more data becomes available and more time-intensive analysis is performed.”
It added that Friday’s quake was also the strongest recorded in Japan since modern readings began 130 years ago.
