THE LANDSCAPE OF WESTERN WASHINGTON--OVERBURDEN AND UNDERBURDEN

The landscape of western Washington owes its modern form to a varied tapestry of geologic processes and geologic materials. Elucidating the form of that landscape has been similarly complex--the myriad pieces of our current understanding continue to be contributed, piece by piece, by a tremendous range of geoscientists. Glacial geologists owe much to the tectonic processes that built the mountain ranges of the Cascades and Olympics, and which also have left an intervening lowland to allow for multiple invasions of glacial ice. That lowland environment has proven to be sufficiently polar to result in a rich glacial record, spanning much (if not all) of the Quaternary, but sufficiently equatorial to permit abundant meltwater and the resulting variety of landforms and deposits characteristic of temperate ice sheets. Great topographic relief and abundant moisture have also accelerated the postglacial processes of fluvial erosion and deposition, superimposing a postglacial fluvial landscape that belies the relatively brief period in which these processes have been active.

The effects of this unique geologic history and suite of geologic deposits are expressed not only by the form of the modern landscape but also by the conditions in that landscape, affecting geomorphic processes, biological systems, and human activity alike. Riverine systems, for example, have emerged as a preeminent concern of the entire Pacific Northwest. Their response to both the unintentional consequences of human populations and the intentional manipulations of engineering works, commonly in the name of economic or ecosystem enhancement, are intimately tied to the geologic setting and associated geomorphic activity. Geologic hazards, as another example, are arrayed very unevenly across this region; our success in recognizing, preparing, and recovering from their effects depends on our understanding of their underlying causes and distribution. Finally, the region as a whole is a place of great variety and great beauty. It has enticed both scientists and non-scientists for well over a century, and it will always sustain our collective interest and enthusiasm for working here.