Category: 2016 Events

12-03-2016 Kathryn Neal: Stabilizing a Coastal Landfill

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About the Talk

STABILIZING PORT ANGELES’ COASTAL LANDFILL

In 1947, the City of Port Angeles created a 25-acre dump at its shoreline, between Ediz Hook and the Elwha River. Over the ensuing 60 years, the site evolved into a 70-acre sanitary landfill with numerous waste containment cells.

Since closure in 2007, and for about 5000 years before that, wave action at the beach site has been continuously eroding the 135-foot tall feeder bluffs. In June 2011, a small exposure of garbage from one of the seaside landfill cells was observed hanging over the edge of the bluff. Further erosion could easily have resulted in a large release of garbage onto the beach since there were only eleven to fifteen feet of native bluff between the eroded face and a 60-foot deep pit of municipal solid waste.

Kathryn Neal will review the geologic setting, bluff retreat rates and the sediment contribution of the bluffs to Ediz Hook, the history of public works construction at the site, wave energy and beach morphology studies that the City conducted, and summarize the design alternatives that the City considered before deciding to relocate the landfill.

In her time with Port Angeles, this has been one of the largest and most significant projects she has been involved in, and arguably the most unique. The project, which was completed this year at a cost of about $21.3M, protects the environment, will last for many decades and was successfully accomplished within the financial constraints of a small city.

 

About the Speaker

Kathryn Neal, P.E. is Civil Engineering Manager with the City of Port Angeles. Kathryn has a Bachelor of Architecture and Civil Engineering from the University of Washington and has been a practicing Professional Engineer since 1994. She grew up in Port Angeles and was thrilled to be able to move back to the Olympic Peninsula about 15 years ago. When she has time off, she enjoys hiking, kayaking, reading, and imagining alternate realities.

02-05-2016 Ralph Dawes: Assembling the PNW

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About the Talk

Assembling the Pacific Northwest

Two hundred million years ago, the west coast was where Spokane is now. This was the edge of the craton—the old part of the continent. How did the rest of the Pacific Northwest come to be here and where did it come from?

The west coast became an active plate boundary when an oceanic plate started to subduct beneath it. As the oceanic plate subducted, blocks of crust that it carried, such as island arcs or oceanic plateaus, were scraped off and added to the edge of the continent in a process known as accretion, thus building the Pacific Northwest we know it today.

Accreted terranes have a different geologic history than the bodies of rock adjacent to them and are separated from their surroundings by major faults. The Crescent Formation of the Quimper Peninsula, for example, is part of a large accreted terrane that underlies much of the coastal Pacific Northwest. The Crescent Terrane originated as piles of basalt which erupted from the sea floor and in some places built broad oceanic islands. This basalt, along with oceanic sediment, was then shoved against and accreted to the continent. Deep thrust faults separate the Crescent Terrane from terranes that had accreted earlier to the Pacific Northwest. Subsequently, the younger oceanic crust has been added seaward of the Crescent Terrane. Each piece of accreted crust is separated from the others by thrust faults, and the subduction zone continues to shift westward as younger terranes are added to the edge of the continent.

The accreted terranes of the Pacific Northwest are a four-dimensional (in time as well as space) jigsaw puzzle that is still being assembled. Western North America was the main testing ground for the development of the accreted terrane concept. We will delve into the discovery that some Pacific Northwest terranes may have moved north more than a thousand miles along the edge of the continent. We will also discuss the current state of knowledge of accreted terranes in the Pacific Northwest, with the Olympic Peninsula representing the leading edge of the North American continent, where terrane accretion continues today.

About the Speaker

Ralph Dawes is originally from Edmonds, WA. He has a degree in literature from Antioch College in Yellow Springs, OH, and degrees in geology from WWU (BS) and the UW (MS, Ph.D.). He has taught geology for the past 23 years, the last 16 at Wenatchee Valley College. He is passionate about sharing how the geologic history of the Pacific Northwest gives insight into the landslides, floods, volcanic eruptions, and earthquakes of today.

2016-10-01 Jeff & Carol Tepper: Ice Age Floods field trip

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About the Field Trip

A Field Trip to Examine the Geology of the Missoula Ice Age Floods

As the last Ice Age was coming to an end, vast quantities of meltwater accumulated in ice-dammed lakes located in what is now western Montana.  Repeated failures of the ice dams resulted in a series of catastrophic floods that swept across eastern Washington between ~15,000 – 13,000 years ago.  These so-called “Missoula floods” were far larger than anything witnessed in historic times and they profoundly changed the landscape of eastern Washington.  On this long two-day trip we will examine some of the features and deposits left behind by these floods, focusing in particular on those that can help us to appreciate their enormity.  The geologist credited with piecing together the story of the Missoula floods, J. Harlan Bretz, spent over 40 years studying the evidence the floods left behind, seeking to convince a skeptical geological community that features such as the Grand Coulee were the result of catastrophic events rather than gradual erosion over a long interval of time.  As we visit many of the same sites that Bretz studied, we will focus on that one fundamental question:  “How do we know we’re seeing the aftermath of cataclysmic events as opposed to merely a long history of gradual erosion?

Saturday, October 1 – Sunday, October 2, 2016.  The trip departs from Fort Worden in Port Townsend at 7 AM and we will return to Port Townsend on Sunday evening (~ 7 PM).

Trip Leaders:  Dr. Jeffrey Tepper (Geology Professor, University of Puget Sound) and Carol Serdar Tepper (Licensed Geologist).

Group Size and Transportation:  This trip is limited to 30 participants.  We will travel together in three 10-person vans. You can leave your personal vehicle at Fort Worden and it will not require a Discover Pass.

Trip Difficulty:  No formal geologic background is required but participants should have an appreciation of geology and be in good physical condition.  Most stops will require walking short distances (less than 0.25 mile) and, in some cases, on uneven ground.  The climb to the top of Steamboat Rock (2.5 miles roundtrip, 800 vertical feet, rocky trail) is moderately strenuous but is optional. Please, no pets or minors (under 21) for logistical and liability considerations.

Lodging: We have reserved a block of rooms (held until September 1 at a motel in Grand Coulee. All participants must stay at the motel with the group. There are a variety of room configurations.  You will receive room reservation information when we have registered you for the trip. You will then have 48 hours to make your room reservation and report the confirmation number to us. Please do not attempt to make room reservations before we have registered you for the trip. Dinner Saturday will be at a restaurant near the motel. Sunday box-lunch is provided.

Trip Cost: The cost of the trip will be $60 per person.  This covers the vans, gas, Sunday box lunch, water, and the trip leaders’ expenses.  Lodging and all other meals are at your expense.