Cat modelling firm EQECAT has increased its market loss estimate for the 11 March earthquake to $22bn to $39bn.
Original loss estimates placed the damage bill between $12bn to $25bn.
More than 50,000 structures were totally or severely damaged and 28,000 people were killed or remain missing.
Damage to buildings and critical infrastructure such as transportation and electricity extend over a very broad region. Damage was caused by the tsunami, direct shaking, and indirectly through soil failure triggered by liquefaction and landslides.
EQECAT said in a statement: “The main factors contributing to this change in loss estimate are damage caused by the onshore water depth (initially reported to be 8 meters), insight on damage from liquefaction, landslides, widespread disruption of electricity and transportation and loss amplification caused by the disruption at the nuclear plant in Fukushima.”
EQECAT said property insurers will be hardest hit, followed by marine, auto, life and personal accident insurers.
Latest information shows severe ground motions affected much of northern Honshu island on 11 March, with strong ground motions persisting for 3 minutes or more in places, and a tsunami producing onshore water depths in excess of 25 meters and extending inland up to 10 kilometres.