January 27, 1700 Tsunami: Cascadia Subduction Zone, United States

An unusually high tidal wave was observed on the coast of the Kii Peninsula and at Ozuchi (Iwate Prefecture). There are no reports about an earthquake. Was this a tsunami of remote origin. (Reference #414, first published in Russian, 1974). Reference #150 lists the source of the tsunami that attacked Otsuchi as off Miyagi Prefecture.

A Pacific tsunami flooded Japanese shores in January 1700. The waters drove villagers to high ground, damaged salt kilns and fishing shacks, drowned paddies and crops, ascended a castle moat, entered a government store house, washed away more than dozen buildings and spread flames that consumed twenty more. Return flows contributed to a nautical accident that sank tons of rice and killed two sailors. Samurai magistrates issued rice to afflicted villagers and requested lumber for those left homeless. A village headman received no advance warning from an earthquake; he wondered what to call the waves. (from p. 27 reference #2479)

Places flooded by the 1700 tsunami in Japan include Kuwagasaki, Tsugaruishi, Otsuchi, Miho and Tanabe. Some of the accounts mention damage in additional villages. In one account, the tsunami takes the form of rough seas that initiate a nautical accident near Nakaminato. (from p. 33 reference #2479)

A trans-Pacific reunion took place in 1996. Orphaned for nearly 300 years, the 1700 tsunami in Japan was reuinted, on the pages of a scientific journal, with an earthquake and tsunami in North America... The orphan dated the earthquake to the evening of January 26, 1700... and gave its approximate size as magnitude 9. (from p.93 reference #2479)

Today the 1700 tsunami is securely linked to a giant North American earthquake. The tie was strengthened in 1997 by tree-ring dating that narrowed the time window for a great Cascadia earthquake to the months between August 1699 and May 1700. The earthquake's enormity was confirmed in 2003 through improved estimates of the tsunami's size and from computer simulations of Cascadia earthquakes and of the tsunami itself... The tsunami's written record in Japan has become clearer too, with discovery in 1998 of the Miho headman's account, authentification in 2002 of the Nakaminato shipwreck certificate and explanation in 2004 of a discordant date from Tsugaruishi. (from p. 93 reference #2479)

The Cascadia Subduction Zone (CSZ) is situated off of the Pacific Northwest coast of North America, from Northern California to Vancouver Island, British Columbia. (from reference #2480)

If the 1700 tsunami came from Cascadia, we can estimate the origin time and magnitude of the earthquake. The earliest documented tsunami arrival time was around midnight on 27 January Japan time, or around 15:00 on 27 January GMT. Because tsunami travel time from Cascadia to Japan is about 10 hours, the earthquake origin time is estimated at around 5:00 27 January GMT or 21:00 on 26 January local time in Cascadia. This time is consistent with Native American legends that an earthquake occurred on a winter night. (reference #2654)

Reference #4153 summarizes oral traditions providing evidence for historical great earthquakes in the Cascadia Subduction Zone. A spectacular example mentioning both a tsunami and ground shaking that occurred just before the tsunami wave arrival, describes the destruction of Loht'a, the principle winter village of the Pachena Bay people on the west coast of Vancouver Island where about 100 fatalities.