Increases your spells' critical strike damage bonus by 50%.
Elemental Fury is a passive shaman ability learned at level 10 for those with the elemental specialization.
Notes
Spell critical strike bonus is normally 50% of base spell damage, meaning a spell that hits for 1000 will crit for 1500, a bonus of 500 damage. Elemental Fury increases the bonus damage by 100%. That means, the bonus damage for this example would be 1000, for a total crit of 2000.
Patch changes
Patch 4.3.0 (29-Nov-2011): Elemental Fury now removes the cooldown from Chain Lightning.
/Patch 3.0.2 (14-Oct-2008): Elemental Fury (Elemental) now requires Elemental Focus as a pre-requisite
Patch 1.11.0 (20-Jun-2006): Tooltip now indicates it increases the critical damage for Searing Totem, Magma Totem, and Fire Nova Totem.