Kaname-ishi (perhaps "foundation stone" but maybe more aptly "cap stone") is a mythological rock that was believed to hold down the Japanese archipelago. It was believed that when it was jostled or disturbed, it caused earthquakes. It is located in Kashima, Ibaraki.
Many earthquakes were believed to have been caused by the catfish Namazu which dwelt near it. The catfish was later restrained by Takemikazuchi, protecting against earthquakes. When the Takemikazuchi lets his guard fall, Namazu thrashes about and agitates the stone, causing violent earthquakes[1]
In the namazu-e or catfish prints of the Edo period, Takemikazuchi/Kashima is depicted attempting to subdue the catfish, protect the stone, and prevent earthquakes.[2] [3] The paintings are believed to give protection against earthquakes themselves, and had a massive increase in popularity.[4]
nl:Cornells Ouwehand
. Namazu-e and Their Themes: An Interpretative Approach to Some Aspects of Japanese Folk Religion . Leiden . Brill . 1964 .