SOUND ECO - MIDTERM

1. Baker River

2. Skaggit River

3. Suak River

4. Stillaguamish River

5. Snohomish River

6. Skykomish River

7. Snoqualmie River

8. Cedar River

9. Duwamish River

10. Green River

11. White River

12. Puyallup River

13. Nisqually River

14. Elwha River

A: Bellingham

B: Seattle

C: Tacoma

D : Olympia

E: Port Angeles

1. Cascade Mountains

2. Mt. Rainier

3. Olympic Mountains

1. Admirality Inlet

2. Hood Canal

3. Central Basin

4. South Basin

5. Whidbey Basin

A: Deception Pass

B: Narrow Bridge

1. Olympic Penninsula

2. Kitsap Penninsula

A: Pacific Ocean

B: Strait of Juan de Fuca

C: Strait of Georgia

D : Lake Washington

E: Lake Sammamish

A: Vancouver Island

B: San Juan Island

C: Whidbey Island

How was the Puget Sound formed?

Glacier movement - a type of moving ice formation

• Vashon Glacier - formed P.S. during Pleistocene Epoch

Tectonic plates - Earth plates that move against each other

• 2 types: Continental and Oceanic (oceanic is heavier)

• Juan de Fuca plates (oceanic) went under North American plate (continental) = subduction

How did the Olympic and Cascade mountains form?

The ‘Juan de Fuca’ Plate collided w/ the North American Plate and subjected

What was the height of the Vashon Glacier? When was it formed?

6k ft at the highest point, 3k at the lowest/front of the glacier (Seattle area)

Formed 20k years ago but retreated back North about 16k years ago

In what order was the Puget Sound formed?

1. Olympic Mountains formed

2. Cascade Mountains formed

3. Vashon glacier coveres the area

What evidence do we have that a glacier ever covered the Puget Sound? Name 3.

1. Erratics - foreign boulders that were found with Canadian origin

2. Drumlines - egg-shaped mounds/hills that are parallel to glacier movements

3. Stiations - scratches in the bedrock caused by glacier abrasions

What alternative evidence is there to glacier presence in the Puget Sound?

Glacier deposits - formed by Glacial Till

• Glacial Till - unsorted sediment

• Glacier Outwash - sorted material

Both are a type of glacier movement that displaces sediment

What is a Moraine? What type of mineral is present?

An accumulation of glacial till deposited by glacial activity

• Sedimentary rock

What is a long narrow lake, formed by a glacial trough?

Ribbon Lakes

• Lake Washington and Sammamish

What sequence of events followed the Great Fires of Seattle in 1889?

• Used the Cedar River and built the Mansory Dam to intake pressurized water in 1915

• Moncton town (1906-1915) was located farther down from the Dam and flooded in 1915 → became Rattlesnake Lake

• Edgewick town flooded due to a failure at Cedar Reservoir in December. 23, 1918

Why did the Masonry Dam flood Monston Town? How could it have been prevented?

Since the Dam was situated on a moraine, the water seeped through it and went down the hill, eventually flooding the town.

This can be prevented by adding a layer of clay between the moraine and water to prevent seepage. Clay is very fine and dense; the water won’t leak through it.

What are the 3 types of rock? Give 1 example each.

Sedimentary - accumulation of sediment, and where fossils form (limestone)

Igneous - magma cools and hardens

• Intrusive - magma cools inside the earth (granite)

• Extrusive - magma cools outside the Earth (basalt)

Metamorphic - formed under the surface of the earth due to heat and pressure

• Foliated - pressure from 1 direction (slate)

• Non-foliated - pressure from multiple directions (marble)

What is the difference between a ‘sound’ and an estuary?

Sound - a large sea/ocean inlet

Estuary - where freshwater and saltwater meet

• 1 or more rivers meet the sea

What is a fjord?

An estuary carved by a glacier

• This makes Puget Sound a fjord estuary

It’s long, deep, narrow and has a U shape from glacial movement

What is a strait?

Naturally formed, narrow waterway that connects 2 large bodies of water

What is the deepest point in the Puget Sound?

Point Jefferson

What is a sill?

An underwater dam that rises in the seabed to separate basins. Forces fresh + salt water to mix at the top of the Sills and accelerates saltwater coming down from the Sills.

• Admirality Inlet

• Hood Canal

• Tacoma Narrow

What is the downside of sills?

Due to little sunlight in deep water, plants can’t photosynthesize, so there's no oxygen at the bottom. When saltwater at the bottom is driven up, it brings polluted oxygen back down, making it harder to flush out pollution.

What is Puget Sound circulation driven by?

• Freshwater from rivers

• Tidal currents

• Inflow of saltwater from the ocean

• Wind strength and direction

What is the residence time for water in the Puget Sound?

6 months before the water gets cycled out

• The Hood Canal takes 1 year since it’s so much more narrow

What are the 2 types of denisty structures?

Stratified: warm + freshwater/ cold + saltwater — the layers are sperated, with saltwater on the bottom due to it being heavier

• Hood Canal

Mixed: water types mix — this is healthier

Why is the Hood Canal so contaminated with low oxygen levels? List 3 reasons

• Slow circulation - water has a long residence time and is only filtered once per year

• Strong stratification - distinct water layers between salt + fresh

• High productivity - high organic load from human involvement

What is the formula to calculate MPH? What about converting Knots to MPH?

MPH = mile (distance) / hr (time)

1 knot = 1.15 MPH → XKnots x 1.15 MPH / 1 knot

What are the 3 main climate controls for the Puget Sound area?

• Pacific Ocean - thermostate + moisture generator

• Topography - alters air flow patterns

• High & low pressure regions located over the North Pacific Ocean