While the coast of the Pacific Northwest becomes populated with houses, condominiums, motels, and restaurants, its beaches and cliffs continue to be altered by ocean currents and winter storms. A companion volume to Living with the Shore of Puget Sound and the Georgia Strait , The Pacific Northwest Coast serves as a source of information about the coast of the Pacific Northwest, its geological setting, the natural responses of beaches and cliffs to ocean processes, and the ever-present problem of erosion. In this guide, Paul D. Komar, one of the nation’s leading coastal oceanographers, examines the lessons taught by ages of geological and cultural history. With explanations of the area’s geological evolution, including natural shoreline erosion and sea-cliff landsliding, Komar details human interaction with the coast: erosion caused by early settlers, the development and destruction of Bayocean Spit, the disastrous effects caused by the 1982–1983 El Niño, and the notorious failure of a construction project on the picturesqueæbut unstableæbluffs at Jump-Off Joe. Emphasizing the actual and potential harm to human projects and to the natural heritage of the coast, Komar provides the knowledge necessary for finding a safe home near the shore while preserving the beauty that draws us to it. "This book offers important lessons and valuable advice to coastal planners and coastal residents--and not just those of Oregon and Washington. The excellent case study material in "The Pacific Northwest Coast "could become part of a curricula for courses in natural hazards, coastal management, and coastal geomorphology. If you care about the coast, this book is a worthy addition to your library." --Douglas J. Sherman, "Geographical Review" Paul D. Komar is Professor of Oceanography at Oregon State University. He is the author of Beach Processes and Sedimentation and the editor of Handbook of Coastal Processes and Erosion . The Pacific Northwest Coast Living with the Shores of Oregon and Washington By Paul D. Komar Duke University Press Copyright © 1998 Duke University Press All rights reserved. ISBN: 978-0-8223-2020-3 Contents Figures, Preface, 1 A Northwest Coast Perspective, 2 Geological Evolution of the Northwest Coast, 3 The Dynamic Northwest Coast, 4 The Arrival of Man—Erosion Becomes a Problem, 5 The Development and Destruction of Bayocean Spit, 6 Natural Processes of Erosion, 7 The 1982-1983 El Niño—An Extraordinary Erosion Event, 8 Sea Cliff Erosion and Landsliding Along the Northwest Coast, 9 The Jump-Off Joe Fiasco, 10 The Northwest Coast—A Heritage to Be Preserved, References, Index, CHAPTER 1 A Northwest Coast Perspective Early explorers of the Northwest coast were impressed by the tremendous variety of its scenery. Today, visitors can still appreciate those qualities. The low, rolling mountains of the Coast Range serve as a backdrop along most of the ocean shores of Washington and Oregon. In the north the tall Olympic Mountains extend right to the shore, as do the Klamath Mountains in southern Oregon and northern California (fig. 1.1). The coast that fronts the mountains is characterized by high cliffs exposed to ocean waves that are slowly cutting away the land (fig. 1.2). The most resistant rocks persist as sea Stacks scattered in the surf. Sand and gravel accumulate only in sheltered areas, where they form small pocket beaches on the otherwise rocky landscape. The longest Stretches of beach are found in the lower-lying parts of the coast away from the high mountains of the extreme north and south. The Long Beach Peninsula, which forms a major portion of the Washington coast, extends northward from near the mouth of the Columbia River as a tongue of land that separates the ocean shores from Willapa Bay. It is the largest sand spit in the Northwest. In Oregon, the longest continuous beach extends about 60 miles from Coos Bay northward to Heceta Head near Florence. This beach is backed by the impressive Oregon Dunes, the largest complex of coastal dunes in the United States. Along the northern half of the Oregon coast fhere is an interplay between sandy beaches and rocky shores (fig. 1.3). Massive headlands jut out into deep water, their black volcanic rocks resisting the onslaught of even the largest storm waves. Between these headlands are Stretches of sandy shore. Portions of these beaches form the ocean shores of sand spits such as Siletz, Netarts, Nehalem, and Bayocean. Landward from most of the spits are estuaries of the rivers that drain the Coast Range. Within each estuary, the fresh water of the river mixes with seawater before passing into the open ocean through the narrow inlet at the tip of the spit. Other bodies of water, such as Netarts Bay and the extensive Willapa Bay in Washington, are inland intrusions of the sea that receive little fireshwater flow from rivers. The first Western explorers and settlers were attracted to the Northwest coast