There are 54 Australians registered in Japan's earthquake and tsunami zones but actual numbers in the area are likely to be higher, the government says.
The Department of Foreign Affairs and Trade (DFAT) said there were no reports of Australian casualties or injuries and it was seeking to contact registered Australians to confirm their well-being.
"This may take some time given communication difficulties in the affected areas," a DFAT statement said on Saturday.
"Our embassy in Tokyo is preparing to send a consular team to the worst affected areas as soon as it is practicable.
"We are waiting for advice from Japanese authorities on when it might be safe to deploy."
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DFAT said there were an estimated 11,000 Australians living in Japan, with most in Tokyo and Osaka. More than 225,000 Australians visit Japan annually.
An Australian parliamentary delegation visiting Tokyo has been confirmed as safe.
All Australian embassy and consulate staff are safe and there is no damage to the embassy in Tokyo or consulate in Sapporo.
"The DFAT crisis centre has been activated in Canberra and the embassy in Japan has activated its crisis plan," DFAT said.
If people have concerns for the welfare of family and friends they believe to have been in the affected areas, they should first try to contact them directly.
If they are unable to contact them and still hold concerns for their welfare, people should call the DFAT's 24-hour Consular Emergency Centre on 1300 555 135. If calling from overseas the number is +61 2 6261 3305.
