Oregon Earthquakes and Tsunamis

Source: Byram 2007.

Every few centuries, on average, the Northwest Coast gets shocked by a massive mega-thrust earthquake, on the order of 8 to 9 on the Richter scale.  On occasion, these produce a devastating tsunami wave.  It wouldn’t be surprising then if such disruptive events featured in aboriginal oral histories and also in the archaeological record itself.  There is a growing body of research on this topic which I am not planning on reviewing at this time, but a nicely focused starting point is a series of papers in the Oregon Historical Quarterly, available online.

 

Model of a Northwest Coast origin tsunami striking Japan. Source: USGS.

 

The four papers draw on both archaeology and oral histories and together make for a well-written, comprehensive and fascinating account of the long-term hazard of living on the Oregon Coast, which is still, of course, vulnerable to seismic and tsunami events.

Tectonic History and Cultural Memory: Catastrophe and Restoration on the Oregon Coast
by R. Scott Byram

Tsunami and Floods in Coos Bay Mythology
by Patricia Whereat Phillips

Weaving Long Ropes: Oral Tradition and Understanding the Great Tide
by Jason T. Younker

Native American Vulnerability and Resiliency to Great Cascadia Earthquakes
by Robert J. Losey

Byram’s paper introduces the volume, and effectively reviews the causes and consequences of tectonic activity along the Pacific coast of North America.  It introduces many of the concepts – geological, linguistic, archaeological – which are found in the subsequent papers, as well as describes a case study on the Coquille River.  Philips, a Coos Tribe member with graduate studies in linguistics, assembles an impressive array of examples of tectonic or tsunami-like events appearing in oral histories or in lexically.  She notes that,

More often in the Hanis language, phrases are used to describe tsunamis, as ‘when the flood time came there was no ebb tide’, ‘now the water rushed in’, and ‘the water ran ashore far across the land’:

Another year, and then the salmon came up river (again). Now they heard something (jingling), everybody went outside and watched it. “Ho! quantities of salmon are coming.” But out in front a baby was being held aloft (on the salmon), and its decorations were what was jingling. “You should not watch a thing like that!” So some of them indeed did not go outside (to look). Now water (a tidal wave) rushed in, and thus all of those people (who had gone outside to look at the salmon baby) drifted away (with the flood). Pretty nearly all the people were gone. [. . . ] The original line describing the tidal wave was in Milluk Coos:

hei-má•tsi-há•p’-he’gwen, wen-gu•s-kwi•-ge’-tkxi-tke-k’a

Now water rushed in, and thus those people drifted away.

Younker is a member of the Coquille Tribe and teaches at Rochester Institute of Technology.  His short paper reviews some Tsunami data, such as the huge  quake of 26th January 1700 (see also) which sent a tsunami from Washington State to Japan, and reflects on the human impact of such events as well as the continuing impact of the oral histories, concluding that,

For me, my uncle taught me a life-long lesson — to never stop weaving my rope. As long as I maintain my rope, I will never be swept away and forget where I am from. And perhaps this is the fundamental purpose of many Native American stories told on the Pacific coast, regardless of the circumstance — to never forget where you are from. I will always be tied to the tallest of trees at South Slough of Coos Bay, Oregon.

Obviously, Flood Stories are a global phenomenon and they may have been selectively recorded and amplified by Christians, ut there is reason to believe that many flood stories do recound natural events, including those found in the Book of Genesis.  Losey’s paper is a fairly detailed analysis of the hazards that aboriginal people would have faced.  How strong were the houses?  How robust  the food supply? How resilient the social structure and kin networks in the face of calamity? These are important questions for contextualizing the risk into human terms.

Overall, these four short papers are a good, readable introduction to traditional and archaeological knowledge of seismic hazards. There is indeed a growing literature on this topic which I’ll try to address at some time in the future, but since the topic today is Oregon, then this page is a portal of sorts to some other research on that topic and this is a very full account of the 1700 earthquake which also reviews palaeo-seismicity in a more technical, yet extremely accessible manner.  In fact, don’t read it since I’ll probably write a post around it some day soon.

Tsunami model of Oregon Coast.  Source.