The energy released on the earth's surface only, MEwhich is the seismic potential for damage, by the 2004 Indian Ocean earthquake and tsunami was estimated at 1.1×1017 joules[17] or 26.3 megatons of TNT. This energy is equivalent to over 1502 times that of the Hiroshima atomic bomb, but less than that of Tsar Bomba, the largest nuclear weapon ever detonated. However, this is but a tiny fraction of the total work done MW (and thus energy) by this quake, 4.0×1029 ergs (40 ZJ)[18], the vast majority underground. This equates to 4.0×1022 J, over 363 thousand times more than its ME. This is a truly enormous figure, equivalent to 9,560 gigatons of TNT equivalent (550 million times that of Hiroshima), or about 370 years of energy use in the United States at 2005 levels of 1.08×1020 J.