Suiattle River Puget Lowland - WA - DNR a y P o r t o T o w n s e n d a B a y D i s c o v r y B y P...
Transcript of Suiattle River Puget Lowland - WA - DNR a y P o r t o T o w n s e n d a B a y D i s c o v r y B y P...
American Lake
Mason Lake
S. F. Skokomish River
N. F. Skokomish River
Black River
Elwha River
Dungeness River
Dosewallips River
Duckabush River
Hamma Hamma River
Vance Creek
Nisqually RiverDeschutes River
Kennedy CreekSkookum Creek
McLane Creek
Puyallup River
Carbon River
South Prairie Creek
White River
Green River
Cedar River
S. F. Snoqualmie River
M. F. SnoqualmieRiver
N. F. Snoqualmie River
Scatter Creek
Skykomish River
S. F. Tolt River
N. F. Tolt River
Sultan River
S. F. Stillaguamish River
Sauk River
Suiattle River
Snohomish River
Duw
amish Waterw
ay
Lake
Was
hing
ton
Lake
Sam
mam
ish
LakeTapps
Lake Cushman
Lake Kapowsin
Tanwax Lake
Ohop Lake
Black Lake
Lake Youngs
Dow Mountain
Cougar Mountain
Tiger Mountain(above glacial ice)
SnoqualmieFalls
Green Mountain
Gold Mountain
Ediz Hook
Dunge
ness Spit
Lemon Hill
Jones Hill
Pinnacle Peak
Spar Pole Hill
Sugarloaf Mountain
Fuller Mountain
Haystack Mountain
Devils Butte
White Star
Dayton Peak
Mount Turner
Mount Walker
Mount Zion
Lookout Hill
Ned Hill
Round Mountain
McDonald Mountain
Striped Peak
Seattle
Tacoma
Olympia
OakHarbor
Port AngelesSequim
Bellevue
Everett
PortTownsend
Sammamish
IssaquahPort Orchard
Bremerton
Edmonds
Sea Tac
Federal WayAuburn
Sea Tac
Renton
Kent
Marysville
Lakewood
Redmond
Shoreline
Lynnwood
Kirkland
Lacey
Puyallup
Bothell
Burien
UniversityPlace
DesMoines
Lake Stevens
Maple Valley
Kenmore
Mukilteo
Mountlake Terrace
Tukwila
Mill Creek
Arlington
Covington
Bonney Lake
Tumwater
Monroe
LakeForest
Park
Woodinville
Snoqualmie
Enumclaw
Newcastle
Shelton
Sumner
Edgewood
Poulsbo
Fife
Snohomish
Dupont
Gig Harbor
Milton
Yelm
Orting
Duvall
Pacific
Tenino
SkokomishIndian
Reservation
SquaxinIndian
Reservation
StillaguamishIndian
Reservation
SnoqualmieIndian
Reservation
MuckleshootIndian
Reservation
NisquallyIndian
Reservation
PuyallupIndian
Reservation
TulalipIndian
Reservation
Sauk SuiattleIndian
Reservation
Port Madison - Suquamish
IndianReservation
Port Gamble - S’Klallam
IndianReservation
JamestownS’Klallam
IndianReservation
Lower ElwhaKlallamIndian
Reservation
C
AN
AL
PU
GE
T
SO
UN
D
Da
bo
b
Ba
y
HO
OD
Sequim B
ay
Port Townsend Bay
D i s c o v e r y Ba
y
Po
r t Su
s an
Po
ss
es
i o n S o
un
d
Sa
ra
to
ga
Pa
ss
a
g e
S k a g i t
B a y
Holm
es Harbor
Ad
mi
ra
lt
y
In
le
t
Dyes Inlet
Sinclair Inlet
PortMadison
Po
rt O
r ch
ar
d
Ea s t P
as s a
ge
CommencementBay
D a l c o P a s s a g e
Taco
ma
Narr
ows
Co
l vo
s P
as s
ag
e
E l l i o tB a y
T
he Great Bend
Ca r r I n l e t
Ni s q
ua
l l y R
e ac h
Ca s e I
nl e
t
Bu
dd
In
l et
E l d
I nl e
t Tot
ten In l et AndersonIsland
McNeilIsland
Fox Island
Harstene Island
Maury Island
VashonIsland
BainbridgeIsland
Whidbey Island
CamanoIsland
K i t s a p
P e n i n s u l a
Mer
cer
Isla
nd
Key
Peni
nsul
a
Manette Peninsula
Toan
dos P
enin
sula
Quimper Peninsula
Miller Peninsula
fault
1
2
3
4
5
6
1
2
3
4
5
6
5
4
3
2
1
6
US Highway 101
US Hig
hway
101
US Highway 101
US
Inte
rsta
te 5
US
Inte
rsta
te 5
US Interstate 5
US
Inte
rsta
te 4
05
US Interstate 90
US Highway 2
0 10 20miles
Co rd i l l e ra n i ce s h ee t
Puget
lobe
N
www.dnr.wa.gov/geology ©2017 Washington Geological Survey
Drumlins - Drumlins (or fluted
ridges) are geologic features where
movement of the ice sheet smooths glacial
sediment into elongated teardrop shapes. Drumlins
align in the direction of the ice flow and are evident across
most of the Puget Lowland.
Mima Mounds - Intriguing features called Mima Mounds are found on
Mima Prairie and in several outwash channels in the southern part of this
map. Composed of organic-rich, sandy soil, Mima Mounds on this map are only
found on the most recent glacial outwash deposits. The origin of the mounds has been
debated for decades and a consensus on their formation has not yet been agreed upon.
Kettles - Glacial kettles are depressions that form when a retreating glacier leaves a bit of ice behind which then
becomes buried by sediment shed from glacial streams. When the block of ice melts, the sediment collapses, forming
a kettle. Kettles can be dry or filled with water, depending on their depth and the level of groundwater in the area.
Eskers - Eskers are snake-shaped landforms that are often found near the glacier’s terminus. Eskers are formed when rivers that are
underneath, on top of, or within a glacier, transport pebble- to cobble-sized gravel that is exposed once the glacier retreats. The resulting landform is a
sinuous ridge of gravel that runs roughly parallel to the direction of ice flow.
Outwash Channels - Dozens of stream channels were created by glacial lake outflows, glacial meltwater streams, and glacial outburst floods. Today, many of the
channels no longer transport water or have smaller streams occupying them than the streams that formed them.
Fault scarps - Sharp breaks in the fluted topography make it easy to identify geologically recent faults, such as this one called the Toe Jam Hill fault on Bainbridge Island west of Seattle, which is
part of the Seattle fault zone.
During the advance and retreat of the Puget lobe, drainages around
the ice sheet were blocked, forming multiple proglacial
lakes. The darker colors on this map indicate lower elevations,
and show many of these valleys. The Stillaguamish,
Snohomish, Snoqualmie, and Puyallup River valleys all once
contained proglacial lakes. There are many remnants of
these lakes left today, such as Lake Washington and Lake Sammamish, east of Seattle.As the Puget lobe retreated, lake outflows, glacial meltwater, and glacial outburst flooding all contributed to dozens of channels that flowed southwest to the Chehalis River
at the southwest corner of this map. Remnants of these
channels can be seen along the eastern and southern edge of the
colored area in the map. Present-day Lake Kapowsin and
Ohop Lake both occupy one of these channels. Today, the Chehalis River flows through a wide valley that
was largely sculpted by ice-age meltwater.
Puget lobe drainage channel
(ice-age Chehalis River)
What is Lidar?The fine detail depicted on this map is the result of lidar. Lidar is a remote-sensing technique that uses light pulses to rapidly collect a very large quantity of elevation points across large areas.To learn more about lidar in Washington visit: www.dnr.wa.gov/lidar
*
During the last ice
advance and retreat (in the latest Pleistocene), an
extension of the Cordilleran ice sheet, called the Puget lobe, covered the Puget Sound region (see location map below).
The colored area of the map (at right) represents the approximate maximum extent of the Puget Lobe during this time period. During glacial maximum, the location of modern-day Seattle (near the center of this map) was beneath 3,000 feet of ice.
All of the land and waterways in this region were shaped, at least in part, by the glacial ice of the Puget lobe. Many large-scale glacial landforms are preserved in the landscape today. In this lidar*-derived map, landforms such as drumlins, kettles, eskers, and glacial stream channels can be seen. Examples of these and other landscape features are enlarged at bottom right.
Most of Washington’s population lives in this region—the glacial geology influences many aspects of daily life, including transportation, water supply systems, agriculture, and building regulations.
Glacial Landforms of thePuget Lowland