There are no immediate reports of casualties or damage.
A strong earthquake shook a Japanese island chain in the Pacific Ocean south of Tokyo, but there was no danger of a tsunami and there were no reports of damage or injuries.
The Tokyo Olympics will open next year in the same time slot scheduled for this year's games.
Japan's Nikkei 225 has surged 8 percent and other world markets also jumped after Congress and the White House reached a deal to inject nearly $2 trillion of aid into an economy ravaged by the coronavirus.
The Tokyo Olympics have been officially postponed until 2021.
Japanese officials have confirmed 99 more people infected by the new virus aboard the quarantined cruise ship Diamond Princess, bringing the total to 454.
Shares are mixed in Europe and Asia after the World Health Organization declared the outbreak of a new virus that has spread from China to more than a dozen countries a global emergency.
A magnitude 7.3 earthquake strikes off Fukushima in Japan. A tsunami warning has been issued.
Olympic leaders have approved the addition of five sports to the program of the 2020 Tokyo Olympics, including the return of baseball-softball and the introduction of youth-oriented events such as skateboarding and surfing.