“Throughout Cascadia (southern Canadian and northern US-American west coast), earth shaking and/or tsunamilike effects are frequently described in stories about the acts and personalities of supernatural beings, often in the guise of animals. Many stories from western Vancouver Island and northern Washington tell of a struggle between Thunderbird and Whale, and throughout Cascadia stories about these ﬁgures frequently include explicit mention or visual imagery suggesting shaking and/or tsunamilike effects.
Thunderbird and Whale are beings of supernatural size and power. A story from Vancouver Island says that all creation rests on the back of a mammoth whale, and that Thunderbird causes thunder by moving even a feather and carries a large lake on his back from which water pours in thunderstorms.
Shaking and ocean surges can be inferred from the story of Thunderbird driving his talons deeply into Whale’s back, and Whale diving and dragging the struggling Thunderbird to the bottom of the ocean (other versions have Thunderbird conquering Whale). Shaking is implied by imagery: Thunderbird lifts the massive Whale into the air and drops him on the land surface.
The struggle between Thunderbird and Whale is unique to the Cascadia coast and appears in stories from Vancouver Island to northern Oregon. From central Oregon south, thunder or whale ﬁgures appear individually in stories describing earthquake or tsunami themes. The central ﬁgures are variously identiﬁed as Thunder, Thunderbird, or bird and Whale, ﬁsh, or sea monster. In northern California, one tribe has an “Earthquake” ﬁgure with “Thunder” as his companion. Stories from Puget Sound and eastern Washington also use these motifs in conjunction with descriptions of earthquake effects.
Thunderbird and Whale stories are part of a systematic oral tradition that used symbolism and mnemonic keys to condense and present information in a format that could be remembered and retold for generations.”
excerpt from Ruth S. Ludwin et al.: “Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories”