Pacific Tsunami Warning Center
The 2004 Indian Ocean earthquake was initially documented as having a moment magnitude of 8.8. In February 2005, scientists revised the estimate of the magnitude to 9.0. Although the Pacific Tsunami Warning Center has accepted these new numbers, the United States Geological Survey has so far not changed its estimate of 9.1. A 2006 study estimated a magnitude of 9.1–9.3; Hiroo Kanamori of the California Institute of Technology estimates that 9.2 is representative of the earthquake's size.