Transcript Cascade Range Volcanoes - Palo Alto Unified School

Cascade Range Volcanoes
MountMt
Jefferson
Rainier
Mt. Hood
Mt.Adams
Mt.Saint Helens
Three Sisters
Types of Volcanoes
California Volcanoes
Mount Lassen
• Elevation 10,457ft
Most recent activity occurred in
1914-1917.
Helen Lake
Lassen Erupts May 22, 1915
Mount Shasta
• Elevation 14,162ft
2nd Tallest Peak in
the Cascades
Shastina
Mt. Shasta debris
anofarea
10avalanche
times thecovers
volume
the
of 450
1980
Mt.square
Saint miles.
Helens
Eruption
Mount Shasta and Haley’s Comet
Oregon Volcanoes
Crater Lake
•Mt. Mazama was 10,80012,000ft
prior
to 8,126ft
collapse
•Hillman
Peak
Highest
point on the rim of the caldera
Wizard Island. A
small cinder cone
volcano.
•Mt. Mazama’s massive
eruption created a caldera,
forming Crater Lake
Mount Hood
• 11,239ft
Most recent eruptive
activity (1760-1810
A.D.) occurred just
prior to Lewis &
Clark’s visit in 1805.
Mount Hood from Portland
Mt. Hood is located
75km Southeast of
Portland, Oregon
Washington Volcanoes
Mount Adams
• 12,276ft
Third Tallest Peak
in the Cascades
Second in eruptive volume only to
Mt. Shasta
Mount Rainier
•
14,410ft
Highest Peak in the
Cascades
Last large eruptions occured
Erupted as recently as the 1840’s 1000 and 2300 years ago.
Tacoma / Puget Sound
Mount Saint Helens
•Emerged from dormancy in
May 1980 with a devastating
eruption.
•Recently became active
again in September 2004
The
Bulge
USGS geologist: Dave Johnston
• 9,677ft
• 9,677ft
• Highest point of
crater rim: 8,364ft
(1,313ft lower)
Pyroclastic Flows
Super-heated gases
mixed with fine
ash, cinders and
volcanic bombs
rush down the
slopes of Mt. Saint
Helens in the days
following the large
eruption.
•David Johnston’s last know location
Before and After
May 18, 1980:
Ashfall in
downtown
Yakima, WA
Smith Creek
Logging Mill on the Banks of
the North Fork Toutle River
Pumice Plain
Tributaries to NF of Toutle Creek
1980
2004
*Note evidence of
erosion taking place on
the pumice plain
Creeks needed to
downcut through
the ash and pumice.
Mudd River
Mt. Shasta
Mt. Saint Helens
Cubic Kilometers of Ejecta from Historic Eruptions