IBARA, Okayama Prefecture--Hidden inside a Buddhist statue housed at a temple here was an account of the last eruption of Mount Fuji three centuries ago and one of the most powerful earthquakes that struck Japan less than two months earlier.

The standing statue of Jizo Bosatsu (Ksitigarbha), a central government important cultural property that dates from the Heian Period (794-1185), has a rectangular hollow cavity carved on its back, which is covered by a long thin strip of wood.

Descriptions of the twin disasters in 1707, which was the fourth year of the Hoei era, are written in ink on the back of that wooden “lid.”

Part of the account reads, “In November, Mount Fuji erupted day and night for 15 days, and volcanic ashes and lapilli fell over Edo (Tokyo) and Suruga (in Shizuoka Prefecture) for 20 days.”

The Hoei eruption occurred on Dec. 16, which was Nov. 23 on the old calendar, 49 days after the Hoei earthquake. The mega-quake, with an estimated magnitude of 8.6, is believed to have killed more than 20,000 people, mainly in central and western Japan.

The account also says a mountain named Kofuji (small Fuji) emerged under Mount Fuji overnight. The volcano is now known as Mount Hoeizan.

“There are few Buddhist statues, if any, that contain such a long written record about a disaster,” said Yoichi Hase, 58, a professor of art history at Kansai University, who is knowledgeable about sculpture. “It can be regarded not only as an art material but also as a historical material.”

The 154-centimeter-tall statue, carved from a single cherry tree, is kept at the Kozanji temple located halfway up the 281-meter-high Mount Kyogamaruyama in western Okayama Prefecture near the border with Hiroshima Prefecture. It was likely founded in the Nara Period (710-784).

According to Shaku Gimyo, 57, chief priest of the temple, the statue was originally kept at the Aizenritsuin temple in today’s Katano, Osaka Prefecture.

Kozanji took it over when Aizenritsuin was abolished in the early Meiji Era (1868-1912) under the Meiji government’s movement to destroy Buddhist property.

The descriptions about the eruption and the earthquake, which were discovered in 1954, are believed to have been written when the statue was at Aizenritsuin.

Hase said Aizenritsuin’s main hall was probably damaged by the Hoei earthquake and that Mount Fuji could have erupted when the damaged statue was being repaired.

A variety of cereals including rice and wheat, as well as hemp fabric, were also found inside the statue.

“The temple’s chief priest and petitioners perhaps wished strongly that victims would be able to rest peacefully and such a disaster would never occur again,” he said.

Hase said people were apparently determined to pass down the disaster to posterity by writing the record on the back of the wooden lid, rather than on a sheet of paper.

“They should have felt regret for sustaining numerous casualties due to the lack of preparedness for an earthquake or eruption,” he said.

Shaku said, “Jizo Bosatsu is a Buddhist entity closest to the people that helps those who died. We would like to convey the thoughts people put into the statue to future generations.”

Those wanting to see the statue must make a reservation in advance.