03-03-2012 Hugh Shipman: Bluffs and Beaches

About the Talk

Bluffs and Beaches:  Geology on the edge (of Jefferson County)

Puget Sound is best distinguished from other large American estuaries by the pervasive influence of the last glaciation.  This glacial legacy includes a steep, irregular coastline, an abundance of coarse-grained sediment, and a shoreline dominated by coastal bluffs.  These bluffs are inherently erosional landforms, although the rate and character of this erosion varies greatly.

Bluffs are a key component of a dynamic beach system that supports an incredible array of coastal landforms and environments, including spits and small estuaries.  This talk will draw on local examples to show how geologic processes have shaped the modern shoreline and how they continue to do so – sometimes with significant implications for people who live near the shore.  The talk will also include observations on how geology is becoming increasingly important to our thinking about how we protect Puget Sound’s shorelines.

About the Speaker

Hugh has been a geologist with the Shorelands Program at the Washington Department of Ecology since 1989.  His interests include coastal erosion, geologic hazards, and the environmental impacts of shoreline modifications. Hugh grew up near the coast of Maine but moved to the Puget Sound region in 1983.

Visit Hugh’s blogs at:

Gravel Beach – http://gravelbeach.blogspot.com/

Washington Coastal Hazards Resilience Network – http://www.wacoastalnetwork.com/blog

 

04-28-2012 Dave Montgomery: DIRT

About the talk

Dirt, soil, call it what you want—it’s everywhere we go. It is the root of our existence, supporting our feet, our farms, our cities. This fascinating yet disquieting book finds, however, that we are running out of dirt, and it’s no laughing matter. An engaging natural and cultural history of soil that sweeps from ancient civilizations to modern times, Dirt: The Erosion of Civilizations explores the compelling idea that we are—and have long been—using up Earth’s soil. Once bare of protective vegetation and exposed to wind and rain, cultivated soils erode bit by bit, slowly enough to be ignored in a single lifetime but fast enough over centuries to limit the lifespan of civilizations. A rich mix of history, archaeology and geology, Dirt traces the role of soil use and abuse in the history of Mesopotamia, Ancient Greece, the Roman Empire, China, European colonialism, Central America, and the American push westward. We see how soil has shaped us and we have shaped soil—as society after society has risen, prospered, and plowed through a natural endowment of fertile dirt. David R. Montgomery sees in the recent rise of organic and no-till farming the hope for a new agricultural revolution that might help us avoid the fate of previous civilizations.

About the speaker

David Montgomery is a Professor of Geology at the University of Washington’s Department of Earth and Space Sciences. He was selected as a MacArthur Fellow in 2008, based on his exceptional creativity, significant accomplishment and potential for subsequent creative work.

01-14-2012 Dave Tucker: Mt. Baker Volcano

About the Talk

Eruptive History and Hazards of the Mount Baker Volcanic Field

On a clear day in Port Townsend, you can’t help but notice Mount Baker to the northeast, just beyond Bellingham. Just 60 miles away, this spectacular volcano lies restless, its history largely unknown until recently.

 The geologic history of the Mount Baker Volcanic Field is now well documented for the past 3-4 million years. The ice-mantled cone of Mount Baker is but the youngest in a long series of eruptive centers, which includes two calderas (large eruptive cauldrons). The past 10,000 years (the Holocene) has seen a decrease in “constructional” lava flows.

Conversely, “destructional” events, such as flank collapses that evolve into far more hazardous lahars are now recognized as the Holocene norm at Mount Baker. Mount Bakers historical record begins in 1843 and ironically is among the most obscure, despite eye-witnesses reports and newspaper accounts. The reasons for the famous “failed-eruption” of 1975 is the latest example of the historic puzzle; this event provided the backdrop to the modern age of volcano monitoring in the Cascade and Aleutian arcs.

About the Speaker

Dave Tucker is a Research Associate in the Geology Department at Western Washington State University (Bellingham) and Director of the Mount Baker Volcanic Research Center, which is the nucleus for ongoing volcanic research at the mountain. Dave has published (2019) Geology Underfoot in Western Washington. The book features several dozen field trips to exciting geologic sites in our region.

Book – Geology Underfoot in Western Washington (field trip guide)