The U.S. Geological Survey on Monday upgraded its official magnitude for Friday's devastating earthquake in northern Japan from an 8.9 to a 9.0.
That's one and a half times more powerful than originally believed.
The move comes after Japanese scientists bumped up the number over the weekend.
The move means that the Tohoku quake, as it has become known, is the fourth largest that has been recorded by modern instruments. It moves up a notch.
The USGS explains:
The USGS often updates an earthquake's magnitude following the event. Updates occur as more data become available and more time-intensive analysis is performed.
The offshore quake sparked a catastrophic tsunami that even did some damage at Southern California harbors.
In one Japanese town alone 10,000 people are believed to be missing; another shoreline village saw 1,000 bodies wash ashore, according to reports.