Grounded in current research, this second edition has been thoroughly updated, featuring new topics, global examples and online material. Written for students studying coastal geomorphology, this is the complete guide to the processes at work on our coastlines and the features we see in coastal systems across the world.
Tide gauges show that global sea level has risen about 7 inches during the 20th century, and recent satellite data show that the rate of sea-level rise is accelerating. As Earth warms, sea levels are rising mainly because ocean water expands as it warms; and water from melting glaciers and ice sheets is flowing into the ocean. Sea-level rise poses enormous risks to the valuable infrastructure, development, and wetlands that line much of the 1,600 mile shoreline of California, Oregon, and Washington. As those states seek to incorporate projections of sea-level rise into coastal planning, they asked the National Research Council to make independent projections of sea-level rise along their coasts for the years 2030, 2050, and 2100, taking into account regional factors that affect sea level. Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future explains that sea level along the U.S. west coast is affected by a number of factors. These include: climate patterns such as the El Niño, effects from the melting of modern and ancient ice sheets, and geologic processes, such as plate tectonics. Regional projections for California, Oregon, and Washington show a sharp distinction at Cape Mendocino in northern California. South of that point, sea-level rise is expected to be very close to global projections. However, projections are lower north of Cape Mendocino because the land is being pushed upward as the ocean plate moves under the continental plate along the Cascadia Subduction Zone. However, an earthquake magnitude 8 or larger, which occurs in the region every few hundred to 1,000 years, would cause the land to drop and sea level to suddenly rise.
The zone where land and sea meet is composed of a variety of complex environments. The coastal areas of the world contain a large percentage of its population and are therefore of extreme economic importance. Industrial, residential, and recreational developments, as well as large urban complexes, occupy much of the coastal margin of most highly developed countries. Undoubtedly future expansion in many undeveloped maritime countries will also be concentrated on coastal areas. Accompanying our occupation of coasts in this age of technology is a dependence on coastal environments for transportation, food, water, defense, and recreation. In order to utilize the coastal zone to its capacity, and yet not plunder its resources, we must have extensive knowledge of the complex environments contained along the coasts. The many environments within the coastal zone include bays, estuaries, deltas, marshes, dunes, and beaches. A tremendously broad range of conditions is represented by these environments. Salinity may range from essentially fresh water in estuaries, such as along the east coast of the United States, to extreme hypersaline lagoons, such as Laguna Madre in Texas. Coastal environments may be in excess of a hundred meters deep (fjords) or may extend several meters above sea level in the form of dunes. Some coastal environments are well protected and are not subjected to high physical energy except for occasional storms, whereas beaches and tidal inlets are continuously modified by waves and currents.
This book assesses the dimensions of our scientific knowledge as it applies to environmental problems in the coastal zone. The volume contains 10 papers that cover different aspects of science, management, and public policy concerning the coastal zone. A consensus is presented on several key issues confronting science for developing a more holistic approach in managing this region's intense human activities and important natural resources.
