The U.S. Geological Survey has revised the strength of last Friday’s earthquake in northeastern Japan from magnitude 8.9 to 9.0.

The agency said it's typical to adjust the magnitude of earthquakes following an examination of the collected data.

The agency initially had the magnitude at 7.9 on the day it occurred and later adjusted it to 8.8 and then 8.9.

Japan's weather agency also raised the magnitude to 9.0 on Sunday.

The March eleventh quake in Japan is the fourth strongest quake recorded in the world since 1900.