IN JANUARY 1700, Native peoples of the Oregon coast faced two extremely dangerous and abrupt threats, a massive earthquake that caused several minutes of intense ground shaking and, a few minutes later, a tsunami that rapidly flooded low-lying areas. Although you might assume that these and earlier earthquakes and tsunamis were devastating for those who lived on the coast, an examination of the archaeological record and oral histories is beginning to reveal the complexity of human and environmental responses to these abrupt natural hazards. To adequately understand the role of these events in the histories of Oregon Native coastal peoples, it is necessary to look not just at the characteristics of the hazards but also at the cultural practices that rendered people both vulnerable and resilient to the short- and long-term effects of these earthquakes and tsunamis on architecture, residential patterns, subsistence, high-investment technologies, political structure, labor, and kinship. It is likely that many long-held cultural practices made Native communities quite resilient to these natural hazards, and it is the interplay between vulnerability and resiliency that is examined here.
Robert J. Losey and Julia Knowles unload excavation equipment for work at site 35-Tl-1 on the shore of Netarts Bay.
Courtesy of R. Scott Byram
Off the coast of northern California, Oregon, Washington, and southern British Columbia is the Cascadia Subduction Zone (CSZ), an area where the eastward-moving oceanic Juan de Fuca plate is being pushed under the thicker continental North America plate. The plates become locked, accumulate strain, and generally cause the coastline to uplift, faster in some areas than others. Every few centuries, the strain is abruptly released in an earthquake that causes coastal areas to sink rapidly in relation to sea level. The massive, sudden movement of the seafloor sends surges of water both out into the Pacific and toward the North American coast. Tsunamis are formed when these rapidly traveling surges reach shallow waters, striking the coast thirty minutes or so after the earthquake.
The geographic extent of the earthquakes and their associated land subsidence may have varied considerably over the centuries. Some earthquakes generated from the CSZ almost certainly ruptured its entire length, from southern British Columbia through northern California. This was likely the case in the most recent Cascadia earthquake in 1700, and virtually every Native community in western Oregon would have been subject to some of its effects. Other earthquakes may have been more localized, affecting smaller sections of the coast. In those cases, communities along one portion of the coast would have suffered the brunt of the earthquake (and perhaps the tsunami), while others would have been much less affected.
Knowing the intensity and duration of ground-shaking associated with these events is critical for understanding how likely it is that homes and other structures were destroyed and that hazardous landslides blocked rivers and caused other difficulties. In all likelihood, those earthquakes that ruptured the entire subduction zone produced minutes of intensive ground-shaking and had the potential to destroy human-built structures and produce numerous landslides. The earthquakes were likely in the magnitude eight to nine range, very similar to the December 26, 2004, earthquake that devastated Sumatra and generated extremely destructive tsunamis.
Some indication of tsunami run-up heights — that is, water height above some known level — is crucial for determining which areas of ancient landscapes and which Native communities may have been flooded. But accurately determining the run-up heights of past tsunamis, let alone modeling the heights of future tsunamis, is a difficult task. Numerous characteristics of the earthquake itself, including the length of the fault rupture and the width and vertical extent of seafloor disturbance, determine tsunami height. The location of offshore canyons and reefs, the formation of the seafloor immediately offshore, and the configuration of bay mouths, among other things, also are important variables. Estimates based on the geological examination of tsunami-deposited sands have indicated run-up heights averaging from twenty-three to thirty feet above sea level. Some flooding likely occurred inland to near the head of tide, which in Oregon can be tens of kilometers inland. Therefore, the extent of tsunami flooding was extensive, but it would have varied geographically and from earthquake to earthquake.
The interval between earthquake/tsunami events determines the regularity with which coastal environments had to respond to earthquake and tsunami disturbance. Perhaps most importantly, their frequency would have factored in the ways people chose to deal with them and how great a threat they were perceived to be. Perhaps it also would have had an effect on how much long-held knowledge a community could draw on. The layers of sediment that slumped from the continental shelf due to extreme shaking, known as turbidites, contain a ten-thousand-year record of large magnitude earthquakes along the Oregon coast. Shorter records of around three thousand years include abruptly submerged and tsunami-covered soils in estuaries. These two records indicate that large earthquakes occurred approximately every six hundred years, but they also indicate a period where two earthquakes struck in a two hundred-year span and another period where nearly a thousand years passed without a large earthquake. As such, a minimum of eight human generations and sometimes as many as forty passed between such geological events. People also occasionally faced tsunamis that originated from distant sources, although they were likely smaller than those generated locally.
Finally, the extent of environmental disturbance associated with earthquakes and tsunamis varied in both duration and intensity. When food resources were severely depleted or stored foods were destroyed during an earthquake or tsunami, people faced nutritional stress. Perhaps the best modern analog is the 1964 Alaskan earthquake, which caused widespread uplift and subsidence of coastal lands and generated a massive tsunami in the Prince William Sound/Kodiak Island region. Coastal uplift associated with the earthquake was devastating to marine fauna, particularly sessile shellfish, which were abruptly and permanently raised above the waterline (or at least raised out of their preferred intertidal zone). Spawning fish, such as salmon, were also disturbed as spawning areas were placed out of reach by uplift or were churned or silted in by surging tsunamis and associated erosion. Subsided areas were much less adversely affected, but surging waves of tsunamis still destroyed some shellfish beds and caused widespread erosion and deposition of sediment in fish and shellfish habitat. The tsunami generated from the 1964 earthquake even caused some damage to shellfish populations in Yaquina Bay on Oregon’s central coast, perhaps through scouring of the bay floor.
Interestingly, less than a year after the 1964 event, surveys of subsided areas of the Alaska coastline revealed that new shellfish beds were forming. Salmon seem to have recovered within a few years, as spawning beds developed in new areas and, in rare cases, the raised water levels following subsidence allowed fish to reach streams that had been inaccessible because of impassible waterfalls. Many salmon were probably unaffected in the immediacy of the earthquake because they were far out to sea and returned to spawning beds months or even years after the disturbance. The environmental disturbance from earthquakes and tsunamis may be short term from a geological and archaeological perspective, but from a human perspective such problems may have been sufficiently long-lived to cause serious problems. It takes only a few weeks of food shortages to cause severe health problems or even death.
Earthquakes and tsunamis are not of themselves disasters or catastrophes. They are perhaps best viewed as hazards — events that present dangers of various scales and durations. Disasters, hazard researchers have recognized, are partly the products of human action; hazards become disasters when people place themselves and their livelihoods in harm’s way. While this perspective can seem to be a case of blaming the victim, it can also be turned on its head. Through their habitual day-to-day actions and long-held cultural practices, people can render potentially disastrous situations much less devastating than might otherwise be the case. Cultural mechanisms that exist for a multitude of functions, such as kinship practices, may also provide avenues of support and knowledge during such crucial periods. Some habitual and long-held cultural practices of Oregon coast Native peoples can be difficult to ascertain directly from the archaeological record, and the best sources for such information are undoubtedly ethnohistoric records. Others, such as settlement patterns, architectural styles, and subsistence are more directly address with archaeological data. I begin here with house architectural styles.
Housing styles on the Oregon coast undoubtedly varied through time, and a reasonably clear archaeological record of houses dates to only the last three thousand years or so. The general form and size of these archaeological houses are quite similar to those in use during the early contact period, from the late 1700s and early 1800s; the characteristics of earlier houses are unknown.
Styles of Native house architecture on the Oregon coast varied geographically, seasonally, from family to family, and according to relative affluence. Temporary, lightly built structures were used primarily for shelter during the warmer and drier months of the year. They lacked heavy beams and posts, presented little threat upon collapse, and could be easily replaced. More relevant here are the heavier post-and-plank houses that were built primarily for winter habitation, although many were also inhabited during warmer months.
Recent observations of earthquakes’ effects on buildings has revealed a number of key architectural features that prevent or at least reduce the chances of collapse. Mud brick structures, those with walls having debris-filled interiors, and those with stone veneers are all particularly susceptible to earthquake-induced collapse. Buildings that are irregular in outline, asymmetrical, or constructed with a variety of building materials (stone, wood, rubble) have also proven to be hazardous. Multiple-story buildings are more dangerous than single-story structures.
Tillamook houses of coastal Oregon, shown here in a sketch based on an Oregon Historical Society three-quarter scale reconstruction, were about sixty feet long and twenty feet wide and were built in pits four to six feet deep. (Sketch by Inaky San Martin, from Space, Style and Structure, ed. Thomas Vaughan, OHS Press, 1974)
Native house styles on the Oregon coast were designed and constructed in ways that, consciously or unconsciously, minimized their risk of collapse during an earthquake. There is no evidence that people used brick or mortar in house construction, and rock appears to have been used primarily for post footings and little else. Houses were apparently symmetrical and regular in outline, either square or rectangular. There is no evidence for true multi-story structures, although rafters were widely used for storage and meat curing. Construction materials typically consisted of wooden planks, several feet in length, set over a post-and-beam framework; beams were set in notches, and cordage was used to secure both beams and planks. Houses often were built over pits that ranged in depth from four to six inches to nearly five feet. All of these factors probably allowed the structures to shift and slump during earthquakes, reducing the likelihood of catastrophic collapse.
Perhaps the biggest danger to house occupants during an earthquake was falling or collapsing overhead architectural elements or stored items. Given that overall house size should correlate with the size or weight of the overhead elements (beams, roofing, and so forth), the general characteristics of house size might provide some coarse estimation of the relative dangers posed by house collapse. Archaeological houses on the northern Oregon coast reach about 60 feet in length; the south coast is characterized by much smaller houses, most no more than 16 feet in width or length.12 Houses over 130 feet in length were present along the Columbia River in the Portland area upstream to The Dalles. All other things being equal, those houses on the south coast would have been less hazardous than those on the north coast, while those found inland on the Columbia River might have presented the most risk (although they might have been subject to less intensive ground-shaking).
Resistance to tsunamis is another matter. The December 26, 2004, earthquake-generated tsunami in Indonesia clearly showed the devastating effects of surging waters on buildings. In some areas, structures that were not built of brick were destroyed and even brick buildings were often undermined by erosion. Similar effects, although of a much smaller scale, were seen in Crescent City, California, following the arrival of tsunami waves generated by the 1964 Alaskan earthquake. In all likelihood, no Native houses on the Oregon coast would have provided safe haven for people during a tsunami. To survive intact, houses would have had to be situated outside the tsunami flood zone.
Replacing plank-and-beam houses lost to tsunamis or earthquakes would have been a costly affair, both in materials and time. Archaeological excavations at Netarts Bay, for example, have shown that houses there were on average around 40 by 16 feet and probably required about 6,000 board feet of lumber (modern two-story American homes require on average 10,000 to 12,000 board feet of lumber). Procuring and processing such a quantity of planks and posts using only stone, wood, and bone tools likely took weeks, if not months, of occasional labor. Less permanent structures could be used during the construction period, but they would not provide the same degree of shelter from the elements and storage space provided by plank houses.
The most obvious way for people to avoid threats posed by great earthquakes and tsunamis is to live outside the affected area. Given that great earthquakes caused strong ground motions across western Oregon, every Native group would have been within the affected area, regardless of any seasonal movement away from the coast. Ground motions during an earthquake are often amplified or dampened depending on a number of factors, but especially important are local soil conditions, particularly the presence of soft, wet sediments. Although there have been no systematic studies on this question, archaeologists generally find that village sites are more often located on higher, well-drained terraces near shorelines rather than on low wetland soils. Stabilized sand dune settings, where houses were often built, likely would have slumped.
Compared with earthquakes, tsunami flooding obviously affected a smaller area of the landscape — the immediate coastline, the margins of estuaries, and low-lying areas of tidal regions of rivers. Geographic residential patterns in western Oregon undoubtedly varied geographically and temporally, but there are a number of commonalities in most archaeological and ethnographic models.
First, coastlines, estuary margins, and tidal portions of rivers were the most densely populated settings in the region. These areas were the most productive portions of the landscape in terms of subsistence, and direct access to waterways was crucial for groups whose primary means of travel and transportation was watercraft. Numerous archaeological habitation sites are found in these zones, most no more than few hundred feet from water’s edge; and most were positioned at only a few feet in elevation.
Second, some portion of or entire Native communities shifted settlement location on a seasonal basis, partly in response to the availability of food resources. This pattern of movement apparently varied widely, both between communities and in them, but one commonality was that estuaries were used as areas of winter settlement and often year-round residence. Tidewater villages often held the largest population aggregations when people gathered for the important winter ceremonial season. During other seasons, people were often more dispersed, moving to the outer coast, upriver to falls or plant-gathering and hunting areas, or elsewhere on the margins of estuaries. Clearly, at least some people were living in harm’s way during any season, but villages upriver would have been better off than those at bay shores and on the outer coast. Given the seasonal movement of people on the landscape, the season of earthquake and tsunami occurrence would have been a major factor in the scope of these events on Native peoples. Of the numerous earthquakes that have struck the Oregon coast over the last ten thousand years, seasonality is only known for the most recent event, which occurred in winter, the worst possible scenario.
Earthquakes and tsunamis likely caused damage to subsistence resources, particularly marine fauna such as shellfish and anadromous fish such as salmon. To what extent did Native people use these resources? How did this vary seasonally and geographically? Little is known about subsistence patterns along the Oregon coast during the earliest periods of its occupation, largely due to the dearth of early sites and the paucity of food remains in them. Much more is known about these patterns over the last three thousand years, when sites become more numerous and faunal and floral remains are better preserved.
Ethnohistoric accounts — including tribal oral histories, Indian agency reports, and other documents — allow researchers to understand how Native people lived on the Oregon coast from the 1820s through the 1850s, and likely for several centures before. This generalized map diagram, which does not represent a specific place, shows the kinds of places Native Americans built residential sites (villages). Estuary shores held the largest population centers, but villages and seasonal camps were located in several different settings.
Courtesy of R. Scott Byram
An examination of faunal and floral remains from Native habitation sites along the Oregon coast reveals that an extensive array of foods was on the menu. Marine and anadromous foods were particularly important, but on-land foods were also extensively used. The options on this menu varied geographically and seasonally. For example, some terrestrial plant foods, such as acorns, appear to have been far more important on the south coast than on the north coast due to the natural distribution of oaks. Some estuaries such as the Nehalem River are shellfish poor, while others, such as Netarts Bay, are shellfish rich, a pattern reflected in food remains found in habitation sites on these bays. Some salmon species, such as chum, were found in abundance in rivers on the north coast but were rare on the central and south coasts. Despite this variability, a suite of resources was universally important on the Oregon coast, particularly salmon, shellfish, elk, deer, pinnipeds, and an array of berries, shoots, and roots. Seasonal food use also varied depending on location, conditions, and needs, but one commonality was the reliance on stored foods during the winter, which typically included dried meats (salmon, elk, clams), dried berries, and rendered sea mammal and fish oils. Such foods were probably stored in the overhead areas and subfloor cellars of winter houses.
Clearly, Native peoples of the Oregon coast were eating foods that were susceptible to earthquake and tsunami disturbance. People also were seasonally dependent on stored foods, which could easily be destroyed in tsunami flooding. As such, some level of nutritional stress was a strong possibility in the immediate aftermath of a great earthquake. If environmental disturbance was long-standing, then extensive population loss, either through starvation or migration, is also a possibility.
The loss of crucial technologies that could not be easily replaced would also place strain on people coping with an earthquake or tsunami. Plank houses were clearly a high-investment technology, both in terms of raw materials and time. Used for shelter and as storehouses, smokehouses, and workshops, their loss would have widespread repercussions.
Given the placement of settlements near waterways, canoes were also undoubtedly crucial in the lives of Oregon Native peoples, who used dugout canoes on rivers, lakes, estuaries, and the open ocean. They allowed people to forage relatively long distances from a central point, to access a variety of aquatic and terrestrial resources, and to transport heavy loads. Canoes were used for any number of other transportation needs and undoubtedly were a major way to exchange information and goods. Their loss would at least temporarily limit subsistence practices, hinder the evacuation of affected areas, and slow the exchange of critical information, such as where temporary shelter or food might be found.
Other relatively high investment items included baskets, nets, and fish weirs or traps. For all of these technologies, the gathering and processing of construction materials were probably more time-consuming than their actual construction. Large fish nets were probably the most expensive, followed by weirs and baskets. Nets and baskets stored in houses could be lost to tsunami flooding, and weirs or traps could be rendered ineffective by changes in water level or damaged by surging waves. Cheaper technologies (in terms of materials and time), such as hooks and lines, dipnets, small weirs, or baskets of expedient materials, might be substituted in the short term. The loss of such technologies would probably not be life-threatening, but it certainly would decrease the efficiency of many daily activities and cause additional economic stress.
POLITICAL ORGANIZATION, LABOR, AND KINSHIP
Northwest coast Native societies often are described as some of the most socially complex hunter-gatherer groups in history. Little definitive assessment can be made about social complexity on the Oregon coast in earlier times, but it is reasonable to suspect that there is some degree of similarity between ethnographic patterns and those of the last thousand years. During the early contact period, societies in present-day Oregon often had a limited number of elite individuals or families, a broad base of commoners, and some slaves. These social levels were likely relatively permanent, passing from generation to generation, but there was generally no strong centralized political organization on most of the Northwest coast, including western Oregon.
The basic political unit on the Oregon coast was the household, a group of often-related individuals who in some cases lived in a single house. Households on the northern coast and the Columbia River often consisted of several families, while those on the south coast were smaller, often based around a single small family. Household units could be fluid, with individuals and families free to withdraw from a household and to join or form others. Households were also free to break from a village group and form their own settlements or join existing ones. Household sizes could be increased or decreased to meet labor needs.
It is only possible to speculate on the ways that political and labor organization played out in the aftermath of Cascadia earthquakes and tsunamis. The lack of centralized power in these societies likely meant that decisions in the face of disaster were made on a household or family level. In those villages suffering from population loss, however, households and families would have faced serious turmoil and likely would have been significantly reconfigured. The fluid nature of villages and households would allow any number of responses, from population dispersal into individual families, to consolidation of families into large households, or some combination of the two. The choices made would be variable and situational. Critical factors would include the pre-existing political situation, the extent of population loss, labor needs, the extent and duration of environmental disturbance, the season of occurrence, and even an individual’s social position. It is also possible that the loss of material wealth, such as boats and houses, and decreased household size was a leveling process, at least in the short term, which left formerly well-to-do individuals or families with little means of maintaining their positions. Personal charisma and authority, however, may have allowed some individuals to continue in or even increase their sway over others. Notably, individuals with little or no status — slaves, for example — and those who had little to gain from group cooperation might take the opportunity to escape their former positions.
Kinship likely played a significant role in the choices made about post-earthquake settlement locations and household organization. Marrying out of one’s village was probably common, and relatives would have provided a support network that linked settlements on adjacent estuaries or coastal settlements to those inland. Relatives would have provided avenues for exchanging information about the reconfigured physical and social environment. Such information might have been critical in the days and weeks following a major earthquake, as people sought out social support, intact homes, and food.
Native oral tradition of the Northwest Coast is both difficult to interpret and laden with a mosaic of cultural information. Nonetheless, numerous recorded accounts provide unique glimpses into the ways people dealt with, explained, and even embraced natural hazards. Prior to Euroamerican contact, Native people of the Northwest coast likely knew and told around one million traditional tales. Perhaps only one thousand, or one percent, have been recorded or passed down to us. Despite this enormous loss of oral history, several stories recounting earthquakes and tsunamis have been identified on the Northwest coast, including Oregon.
Some recollections of ground-shaking or sudden floods from the ocean appear to refer to the 1700 Cascadia earthquake and tsunami. Many other accounts lack such time signifiers and are impossible to associate with geologically known earthquakes or tsunamis. That such stories are recalled at all should not be surprising, given the potential of earthquakes and tsunamis to demonstrate extraordinary powers and to cause a sudden widespread loss of life and considerable landscape change. Given that this oral tradition is found among groups spanning the subduction zone, it is likely there was some level of common experience in dealing with the hazards. Perhaps survivors felt some comfort in sharing their stories with others in the region who had similar experiences.
The first recorded oral traditions about apparent CSZ events date to the 1860s. Why did people keep telling these stories more than 150 years after the 1700 earthquake and tsunami? One reason is that the storytellers believed that the events and their effects were worth remembering and that telling the stories might give listeners some means for coping with and understanding future earthquakes and tsunamis. Stories often recall the specific behavior of people who survived. An account of a tsunami at Nehalem Bay, for example, recalls that some individuals were spared the loss of their homes and goods because they heeded the warning of an approaching tsunami and moved their materials up a hill. Similar practical steps to survival are suggested today along the Oregon coast through the numerous “Tsunami Evacuation Route” signs that direct people to higher ground.
Some accounts of tsunamis and earthquakes depict these events as beneficial, at least for the survivors. The Tolowa, Athapaskan speakers of Oregon’s far south coast, have a story that closely ties their origin to an earthquake-generated tsunami that cleansed the earth, leaving only the chosen to populate the area. Farther south, ethnographers working among the Yurok of the Klamath River area report in many stories that Earthquake is a personified character. In at least one story, Earthquake, along with his partner Thunder, travel along the coast sinking coastal prairies into the ocean, creating estuaries and lagoons. These happenings are described in a positive way — the estuaries and lagoons and the fish and shellfish in them are depicted as essential to Yurok life. Such stories are not simple recollections of past events but also elaborate explanations of landscape evolution and the peopling of the known world. They likely reflect the varied roles earthquakes and tsunamis played in the short- and long-term histories of Oregon’s Native peoples.
THE ROLE OF GREAT EARTHQUAKES and tsunamis in the histories of Oregon’s Native peoples is complex. Of the immediate hazards posed to communities by these events, tsunami flooding was the most significant. While earthquakes likely caused some dangerous landslides and houses to collapse, the surging waters of tsunamis were probably more widespread and life-threatening. Longer-term hazards, such as reduction of the subsistence base through environmental disturbance, are still little understood; but some level of nutritional stress was likely present, particularly in the weeks and months after an earthquake.
Some cultural practices such as living near waterways and reliance on stored foods during winter placed a significant portion of the population at considerable risk. House construction methods and other cultural practices may have minimized some of the risks. Oral histories may have provided critical direction to those facing these hazards, and accounts of positive outcomes may have provided some level of solace to survivors.
Obviously, coastal communities today have some advantages over Native groups three hundred years ago — national and international disaster response networks, a globalized food base, varied forms of transportation, and some ways of warning people (at least for tsunamis). In other ways, however, we are at more risk today than we have ever been. Modern buildings can pose serious risks to inhabitants when they are subject to strong ground motions, and electricity and natural gas have created significant fire hazards. Large populations currently live in tsunami inundation zones, and ports and roads are in harm’s way. Today, there is little oral tradition about earthquakes and tsunamis among residents of coastal communities or the thousands of tourists that visit them each year. The detailed examination of the geological record has helped raise awareness of the potential hazards posed by Cascadia earthquakes and tsunamis, at least at a government level. It is my hope that archaeology will heighten this awareness by telling the long-term human history of how people have coped with these incredible hazards through the centuries.
1. See Paul D. Komar, The Pacific Northwest Coast (Durham, N.C.: Duke University Press, 1997); and William Orr and Elizabeth L. Orr, Geology of Oregon (Dubuque, Iowa: Kendall-Hunt, 2000). See also Brian F. Atwater, “Evidence for Great Holocene Earthquakes Along the Outer Coast of Washington State,” Science 236 (1987): 942–44; idem and Eileen Hemphill-Haley, “Geological Evidence for Earthquakes during the Past 2000 Years along the Copalis River, Southern Coastal Washington,” Journal of Geophysical Research 97 (1992): 1901–19; Curt Peters and Mark Darienzo, “Coastal Neotectonic Field Trip Guide for Netarts Bay, Oregon,” Oregon Geology 50 (1988): 99–117; “Discrimination of Climatic, Oceanic and Tectonic Mechanisms of Cyclic Marsh Burial from Alsea Bay, Oregon, U.S.A,” U.S. Geological Survey Open File Report 91–441-C (1991); Mark Darienzo and Curt Peterson, “Episodic Tectonic Subsidence of Late Holocene Salt Marshes, Northern Oregon Central Cascadia Margin,” Tectonics 9 (1990): 1–22; “Magnitude and Frequency of Subduction-Zone Earthquakes along the Northern Oregon Coast in the Past 3,000 Years,” Oregon Geology 57 (1995): 3–12; Brian F. Atwater and David K. Yamaguchi, “Sudden, Probably Coseismic Submergence of Holocene Trees and Grass in Coastal Washington State,” Geology 19 (1991): 706–09; S.H. Clarke and G.A. Carver, “Late Holocene Tectonics and Paleoseismicity, Southern Cascadia Subduction Zone,” Science 255 (1992): 188–92; J.J. Clague and P.T. Bobrowsky, “Evidence for a Large Earthquake and Tsunami 100–400 Years Ago on Western Vancouver Island, British Columbia,” Quaternary Research 41 (1994): 176–84; A.R. Nelson et al., “Radiocarbon Evidence for Extensive Plate-Boundary Rupture about 300 Years ago at the Cascadia Subduction Zone,” Nature 378 (1995): 371–74; I. Shennan et al., “Tidal Marsh Stratigraphy, Sea-level Change and Large Earthquakes—I: A 5000 Year Record of Large Earthquakes in Washington, USA,” Quaternary Science Reviews 15 (1996): 1023–59; H.M. Kelsey et al., “Response of a Small Oregon Estuary to Coseismic Subsidence and Postseismic Uplift in the Past 300 Years,” Geology 26 (1998): 231–34; H.M. Kelsey, et al., “Plate-boundary Earthquakes and Tsunamis of the Past 5500 Yr, Sixes River Estuary, Southern Oregon,” Geological Society of America Bulletin 114 (2002): 298–314; I. Shennan et al., “Tidal Marsh Stratigraphy, Sea-level Change and Large Earthquakes—II: Submergence Events during the Last 3500 Years at Netarts Bay, Oregon, USA,” Quaternary Science Reviews 17 (1998): 365–93.
2. Kelsey, “Plate-boundary Earthquakes and Tsunamis.”
3. R.S. Yeats, Living with Earthquakes in the Pacific Northwest (Corvallis: Oregon State University Press, 1998), 52.
4. See, for example, the tsunami inundation maps for the Oregon coast, prepared by the Oregon Department of Mineral Industries; and G.R. Priest, “Explanation of Mapping Methods Use of the Tsunami Hazard Maps of the Oregon Coast,” Open-File Report 0–95–67, Department of Geology and Mineral Industries, Portland.
5. Max K.F. Ng et al., “Simulation of Tsunamis from Great Earthquakes on the Cascadia Subduction Zone,” Science 250 (1990): 1248–50; Kenji Satake et al., “Time and Size of a Giant Earthquake in Cascadia Inferred from Japanese Tsunami Records of January 1700,” Nature 379 (1996): 246–51.
6. J. Adams, “Paleoseismicity of the Cascadia Subduction Zone — Evidence from Turbidites off the Oregon-Washington Margin,” Tectonics 9 (1990): 569–83.
7. See Atwater, “Evidence for Great Holocene Earthquakes”; Atwater and Hemphill-Haley, “Geological Evidence”; Peterson and Darienzo, “Coastal Neotectonic” and “Discrimination”; Darienzo and Peterson, “Episodic Tectonic” and “Magnitude and Frequency”; Atwater and Yamaguchi, “Sudden, Probably”; Clarke and Carver “Late Holocene”; Clague and Bobrowsky “Evidence for”; Nelson et al., “Radiocarbon Evidence”; Shennan et al., “Tidal Marsh”; Kelsey et al. “Response of a Small Oregon Estuary”; Shennan et al., “Tidal Marsh”; Kelsey et al.,”Plate-boundary.”
8. See Robert J. Losey, “Earthquakes and Tsunamis as Elements of Environmental Disturbance on the Northwest Coast of North America,” Journal of Anthropological Archaeology 24 (2005): 101–16.
9. See G.H. White, ed., Natural Hazards: Local, National, Global (London: Oxford University Press, 1974); P.D. Sheets, “Archaeological Studies of Disaster: Their Range and Value,” Natural Hazards Research Working Papers #38 (University of Colorado, Boulder, 1980); A. Oliver-Smith and S.M. Hoffman, eds., The Angry Earth: Disaster in Anthropological Perspective (New York: Routledge Press, 1999); S.M. Hoffman and A. Oliver-Smith, eds., Catastrophe and Culture: The Anthropology of Disaster (Santa Fe, N.M.: School of American Research, 2002); G. Bawden and R.M. Reycraft, eds., Environmental Disaster and the Archaeology of Human Response, Maxwell Museum of Anthropology, Anthropological Papers No. 7 (Albuquerque: University of New Mexico, 2000); R. Torrence and J. Grattan, eds., Natural Disasters and Culture Change (London: Routledge Press, 2002).
10. See Robert J. Losey “House Remains at Netarts Sandspit Village, Oregon,” Journal of Field Archaeology 30 (2005): 401–17; K.M. Ames and H.D.G. Maschner, Peoples of the Northwest Coast (New York: Thames and Hudson, 1999): 147–76; W.R. Suttles, ed., Handbook of North American Indians, vol. 7 (Washington, D.C.: Smithsonian Institution, 1990); and J. Vastokas, “Architecture of the Northwest Coast Indians of North America” (Ph.D. diss., Columbia University, 1966).
11. R.L. Kovach, Early Earthquakes of the Americas (Cambridge: Cambridge University Press, 2004), 43–44.
12. See Losey, “House Remains.”
13. Kenneth M. Ames, “Life in the Big House: Household Labor and Dwelling Size on the Northwest Coast,” in People Who Lived in Big Houses: Archaeological Perspectives on Large Domestic Structures, ed. G. Coupland and E.B. Banning, (Madison, Wisc.: Prehistory Press, 1996): 131–50; Ames et al., “Household Archaeology of a Southern Northwest Coast Plank House,” Journal of Field Archaeology 19 (1992): 275–90.
14. Dennis M. Powers, The Raging Sea: The Power Account of the Worst Tsunami in U.S. History (New York: Citadel Press Books, 2005).
15. See Losey, “House Remains.”
16. See Rick Minor and Katherine Toepel, “Patterns of Aboriginal Land Use in the Southern Oregon Coastal Region,” in Prehistoric Places on the Southern Northwest Coast (Seattle: Burke Museum, 1983), 225–53; R.L. Lyman and R. Ross, “Harpoon Stone Tips and Sea Mammal Hunting on the Oregon and Northern California Coast,” Journal of California and Great Basin Anthropology 10 (1988): 73–87; Jay Miller and William R. Seaburg, “Athabaskans of Southwestern Oregon,” in ed. W. Suttles, Handbook of North American Indians, vol. 7, Northwest Coast. (Washington, D.C.: Smithsonian Institution, 1990): 580–88; Henry Zenk, “Siuslawans and Coosans,” in ed. Suttles, Handbook, 572–79; R. Lee Lyman, Prehistory of the Oregon Coast (San Diego: Academic Press, 1991), 82–83; Mark A. Tveskov, “The Coos and Coquille: A Northwest Coast Historical Anthropology” (Ph.D. diss., University of Oregon, 2000); R. Scott Byram, “Brush Fences and Basket Traps: The Archaeology and Ethnohistory of Tidewater Weir Fishing on the Oregon Coast” (Ph.D. diss., University of Oregon, 2002); Elizabeth D. Jacobs, The Nehalem Tillamook, An Ethnography (Corvallis: Oregon State University Press, 2003).
17. For simplicity, I am excluding here the Portland Basin, which was undoubtedly densely populated during the late Holocene.
18. See Madonna L. Moss and Jon M. Erlandson, “An Evaluation, Survey and Dating Program for Archaeological Sites on State Lands of the Southern Oregon Coast,” Oregon State Historic Preservation Office, Salem, Ore., 1994; “An Evaluation, Survey and Dating Program for Archaeological Sites on State Lands of the Northern Oregon Coast,” Oregon State Historic Preservation Office, Salem, Ore., 1995; Lyman, Prehistory of the Oregon Coast; Tveskov, The Coos; Byram, “Brush Fences”; Robert J. Losey, “Communities and Catastrophe: Tillamook Response to the AD 1700 Earthquake and Tsunami, Northern Oregon Coast” (Ph.D. diss., University of Oregon, 2002).
19. G.C. Jacoby et al., “Tree-ring Evidence for an AD 1700 Cascadia Earthquake in Washington and Northern Oregon,” Geology 25 (1997): 999–1002; D.K. Yamaguchi et al., “Tree-ring Dating the 1700 Cascadia Earthquake,” Nature 389 (1997): 922.
20. Jon M. Erlandson et al., “The Development of Maritime Adaptations on the Southern Northwest Coast of North America,” Arctic Anthropology 35 (1998): 6–22.
21. Jon M. Erlandson and Madonna L. Moss, “The Systematic Use of Radiocarbon Dating in Archaeological Surveys in Coastal and Other Erosional Environments,” American Antiquity 64 (1999): 431–43.
22. Publicly accessible sources include Lyman, Prehistory; Roberta Hall, ed., People of the Coquille Estuary: Native Use of Resources on the Oregon Coast (Corvallis: Words and Pictures, 1995); Thomas J. Connolly, Human Responses to Change in Coastal Geomorphology and Fauna on the Southern Northwest Coast: Archaeological Investigations at Seaside, Oregon, University of Oregon Anthropological Papers, 45 (Eugene: University of Oregon, 1992); Rick Minor et al., “The Siuslaw Dune Site: Archaeology and Environmental Change in the Oregon Dunes,” in Changing Landscapes: Proceedings of the 3rd Annual Coquille Cultural Preservation Conference, 1999 (North Bend, Ore.: Coquille Indian Tribe, 2000): 82–102; Tveskov, The Coos; Losey, Communities; Roger H. Colten, “Prehistoric Marine Mammal Hunting in Context: Two Western North American Examples,” International Journal of Osteoarchaeology 12 (2002): 12–22; Robert J. Losey, et al., “Exploring the Use of Red Elderberry (Sambucus racemosa) Fruit on the Southern Northwest Coast of North America,” Journal of Archaeological Science 30 (2003): 695–707; Losey et al., “Late-Holocene Dungeness Crab (Cancer magister) Harvest at an Oregon Coast Estuary,” Journal of Archaeological Science 31 (2004): 1603–12; Losey and Eleanor Power, “Shellfish Remains from the Par-Tee Site (35-CLT-20), Seaside, Oregon: Making Sense of a Biased Sample,” Journal of Northwest Anthropology 39 (2005): 1–20.
23. See Jacobs, The Nehalem; Zenk, “Siuslawans”; Miller and Seaburg, “Athabaskans”; Tveskov, The Coos.
24. See Byram, “Brush Fences,” 332.
25. Kenneth M. Ames, “Going by Boat: The Forager-Collector Continuum at Sea,” in Beyond Foraging and Collecting: Evolutionary Change in Hunter-Gatherer Settlement Systems (New York: Kluwer Academic/Plenum Publishers, 2002): 19–52.
26. Detailed data on time and material investment in such structures are rare. Quantified assessments of time spent gathering and constructing nets for terrestrial mammal hunting can be found in Karen D. Lupo and Dave N. Schmitt, “Upper Paleolithic Net-Hunting, Small Prey Exploitation, and Women’s Work Effort: A View from the Ethnographic and Ethnoarchaeological Record of the Congo Basin,” Journal of Archaeological Method and Theory 9 (2002): 147–79.
27. Kenneth M. Ames, “Chiefly Power and Household Production on the Northwest Coast,” in Foundations of Social Inequality (New York: Plenum Press, 1995): 155–87; Ames and Maschner, Peoples.
28. Ames, “Chiefly Power.”
29. Losey, “House Remains.”
30. Ames, “Chiefly Power,” 172.
31. Yvonne Hajda, “Regional Social Organization in the Greater Lower Columbia, 1792–1830” (Ph.D. diss., University of Washington, 1984); Jacobs, The Nehalem, 107; Tveskov, The Coos, 80–84.
32. Melville Jacobs, “Areal Spread of Indian Oral Genre Features in the Northwest States,” Journal of the Folklore Institute 9 (1972): 10.
33. See Robert J. Losey, “Oral Tradition of Earthquakes and Tsunamis on the Central Cascadia Coast: Variation of Accounts and Relations to Historically Observed Patterns Across the Northwest Coast,” in Telling Our Stories, Proceedings of the 4th Annual Coquille Cultural Preservation Conference, 2000 (North Bend, Ore.: Coquille Indian Tribe, 2001): 3–15; Losey, Communities, 117–67; Deborah H. Carver, “Native Stories of Earthquakes and Tsunamis, Redwood National Park, California,” Report to the National Park Service (Crescent City, Calif.: Redwood National and State Parks, 1998); Alan D. McMillan and Ian Hutchinson, “When the Mountain Dwarfs Danced: Aboriginal Traditions of Paleoseismic Events along the Cascadia Subduction Zone of Western North America,” Ethnohistory 49 (2002): 41–67; Ruth S. Ludwin et al., “Dating the AD 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories,” Seismological Research Letters 76 (2005): 140–48.
34. Ludwin et al., “Dating.”
36. Carver, “Native Stories,” 12; Loren Bommelyn, “The Prolegomena to the Tolowa Athabaskan Grammar” (M.A. thesis, University of Oregon, 1997); James Collins, Understanding Tolowa Histories: Western Hegemonies and Native American Responses (New York: Routledge Press, 1998): 141.
37. Published accounts of Yurok oral tradition recalling earthquakes or tsunamis can be found in Robert Spott and Alfred L. Kroeber, “Yurok Narratives,” University of California Publications in American Archaeology and Ethnology 35 (1942): 143–256; Alfred Kroeber and Edward W. Gifford, “World Renewal: A Cult System of Native Northwestern California,” University of California Anthropological Records, 13 (1949): 1–156; Theodora Kroeber, The Inland Whale (Bloomington: Indiana University Press, 1959); Alfred Kroeber, Yurok Myths (Berkeley: University of California Press, 1976); Carver, “Native Stories.”
38. Kroeber, Yurok Myths, 174–78.