Puget Sound


Puget Sound is a very large salt water estuary, or system of many estuaries, fed by highly seasonal freshwater from the Olympic and Cascade Mountain watersheds. The Sound was carved by the scouring action and till deposition of the Wisconsin Glaciation, which extended in this region as far south as Olympia; the soils of the region, less than ten thousand years old, are still characterized as immature. The Puget Sound system consists of four deep basins connected by shallower sills. The four basins are Hood Canal, west of the Kitsap Peninsula, Whidbey Basin, east of Whidbey Island, South Sound, south of the Tacoma Narrows, and the Main Basin, which is further subdivided into Admiralty Inlet and the Central Basin. Puget Sound's sills, a kind of submarine terminal moraine, separate the basins from one another, and Puget Sound from the Strait of Juan de Fuca.  

Anglo settlement of the Pacific Northwest, which dates to the mid-1800s, was fairly recent by comparison with much of the North American continent. Since that time, the land cover of the region, which once was mostly coniferous forest, has changed dramatically as the population has grown. In the first 100 years or so of the post-settlement era, the major land use conversion was associated with forest harvest, and some areas have undergone several cycles of forest harvest and regrowth. Expansion of the major metropolitan areas, such as the Everett-Seattle-Tacoma corridor of western Washington, has resulted in conversion of substantial portions of the landscape from forest to urban and suburban uses. According to census data from the State of Washington's Office of Financial Management, the population density of the most populated counties in the Puget Sound basin has increased as much as 36 times since 1900. Currently, about 70% of Washington's population lives in the Puget Sound basin. Concerns have been raised about the effects of ongoing land use change on various aspects of the hydrologic cycle, including summer low flows, groundwater recharge, and flooding, and what the consequent effects on marine circulation and community structure might be.

We are pursuing the integration of research and education on the environment of Puget Sound through PRISM (Puget Sound Regional Synthesis Model), a University of Washington campus wide initiative. As a research and education initiative, PRISM's mission is to build capacity in to examine confront these issues today, through field and modeling activities. Given the complexities in developing such models, and in developing the underlying data bases, significant effort is given to developing improved "cyber- infrastructure" and visualization techniques.