Economists say the major earthquake that hit central Japan on New Year's Day will deal a heavy blow to the country's GDP. They estimate the economic impact to run into the hundreds of millions of dollars and say the figure could rise as the full extent of the damage becomes clear.

Heavily affected Ishikawa Prefecture is a hub for machinery, semiconductor and food factories. It's also known for its agriculture and fishing, as well as traditional crafts.

Economists at Nomura Securities say Japan's GDP could drop by 160 to 340 million dollars as a result of the quake.

The estimate is based on the assumption that economic activity stops for up to one month in seven cities and towns in Ishikawa.

They also say this projection could rise even further, depending on whether effects to the supply chain spread to other regions.

SMBC Nikko Securities says the GDP could drop by about 440 million dollars. They say obstructed roads will limit production activity in Ishikawa, Toyama, Fukui and Niigata prefectures until around March.