Page 461 - (DK) Ocean - The Definitive Visual Guide

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PACIFIC OCEAN I3 PACIFIC OCEAN L4
Gulf of Alaska Cascadia Basin

AREA 600,000 sq. miles (1.5 million sq. km) AREA 66,000 sq. miles (170,000 sq. km)
MAXIMUM DEPTH 16,400 ft (5,000 m) MAXIMUM DEPTH 9,600 ft (2,930 m)
INFLOWS Susitna, Copper rivers; icebergs from INFLOWS Pacific Ocean; Columbia, Fraser rivers
numerous glaciers
The Cascadia Basin is the last remnant
A counterclockwise subpolar gyre extends of the original eastern Pacific oceanic
across the north Pacific and into the plate, the Farallon Plate, which has
Gulf of Alaska, fed by the warm waters been almost entirely subducted beneath
of the northern Kuroshio Extension, North America. The Cascade Range
the extension of the Kuroshio Current. of volcanoes in Oregon and Washington
The surface waters are cooled and State, including Mount St. Helens, are
become less saline due to precipitation a product of this subduction. Mount
as they cross the ocean. Many of the St. Helens erupted in a catastrophic
storms that lash the west coast of ALASKAN FJORD explosion in 1982, killing 57 people,
Canada originate in the Gulf of The valleys and fjords of the Alexander Fuca Plate west of Vancouver Island. and still shows signs of activity.
Alaska. The circulation is completed as Archipelago testify to extensive erosion The seamounts were created above the Earthquakes and associated tsunamis
the Alaska Current and the Aleutian by glaciers during the last ice age. hotspot over the last 30 million years, are also a risk in the area, although
Current return west along the Alaskan then carried northwest by seafloor the last major earthquake is thought
coast and south of the Aleutian Islands. were born. The floor of the Gulf of spreading. Since 1977, oil has been to have been in 1700. The underlying
The gulf’s waters are very productive, Alaska is peppered with seamounts. shipped through ports on the south ocean crust appears to be split into
providing feeding grounds for many There are two main chains: the Patton coast of Alaska. In 1989, Prince William three small plates. The largest is
species of fish. Pacific salmon spend and Gilbert seamounts, and the Kodiak Sound was the site of one of the worst the Juan de Fuca Plate, named after
up to five years at sea, much of it in Seamounts, both running away from maritime environmental disasters, when a Greek sea captain who explored
the gulf and adjacent seas, before the Alaska Peninsula. Their origin is the tanker Exxon Valdez ran aground, the area for Spain in 1592. The
returning to spawn in the Asian and the Cobb Hotspot, situated beneath releasing about 30 million gallons Explorer Plate lies to the north and
North American rivers where they the spreading center of the Juan de (114 million liters) of crude oil. the Gorda Plate to the south.

G H I J K L

160˚W 150˚W Arctic Circle 140˚W 130˚W 120˚W 110˚W
SCALE KEY
0 100 200 300 400 500 km sea level
800 ft
UNITED S T A TES 0 100 200 300 400 500 miles (250 m) 1
OF AMERICA
1,600 ft
Yukon River 60˚N (500 m)
3,300 ft
(1,000 m)
6,500 ft
(2,000 m)
Kuskokwim River (3,000 m)
9,800 ft
16,400 ft
(5,000 m)
Anchorage CANAD A 2
Cordova land
Kenai
Peninsula
seamount
Cook Inlet Homer Seward William Cape Yakutat Glacier Chichagof Admiralty sea depth
Juneau
Prince
Saint Elias
Sound
maximum depth
Bay
on map
Island
295m
Sitka
boundary
Shuyak Portlock Bank (968ft) Gulf of Alaska 3,640m Island Baranof tectonic plate
Island
Alaska Peninsula Kodiak Seamount Prince Rupert
Cape (11,943ft) Island Ketchikan
Constantine Shelikof Strait Kodiak Alexander Archipelago Prince of
Pratt
Bristol Gulf of Alaska Seamount Province Wales
Quinn
Bay Island Giacomini Seamount Durgin Island Dixon 3
Entrance
Seamount
Seamount
Cape
Surveyor
Seamount
Seamounts
Welker Kodiak Dickins Knox Hecate Strait 213m
Seamount
Port Moller Seamount Denson (699ft) 50˚N
A l e u t i a n Tr e n c h Seamount Seamount Seamount QueenCharlotte Strait of Georgia
Patton
Shumagin Seamount Patton Alaska Plain Seamount Bowie Queen Charlotte Islands Cape
Islands Seamounts Miller Seamount St.James
Sound
Oshawa
Vancouver
Murray
Cape
Gilbert
Seamount
Seamount White Marsh Scott Vancouver Island ATLAS OF THE OCEANS
Victoria
Strait of
Parker Juan de Fuca Seattle 4
Seamount Schoppe Ridge Explorer
Gibson Seamount
Seamount Peters Ridge UNITED
STATES OF
G i l b e r t S e a m o u n t s
5,267m 766m Cascadia AMERICA
(17,281ft) (2,513ft)
160˚W 150˚W 140˚W 130˚W Basin
G H I J K L