In your answer, include a discussion of:
- the plate tectonic process involved
- the origin of the magma and rocks
- the composition of the magma and rocks
- the type of eruptions that occur there
- other geologic features associated with Andean-type mountains.
Extra Links for Writing Assignment 1, Geology 100
IN ADDITION TO THE PARTS OF THE TEXT REFERRED TO IN THE ASSIGNMENT, you might consider the
following ‘enrichment’:
Part 1. Hypothesis vs. Theory — Continental Drift vs. Plate Tectonics
For starters, consider the following Smithsonian Magazine article from 2012, entitled When Continental Drift
Was Considered Pseudoscience: http://www.smithsonianmag.com/science-nature/when-continental-drift-wasconsidered-pseudoscience-90353214/?all
Here’s a recent perspective from Naomi Oreskes, Nature Magazine, entitled How plate tectonics clicked:
http://www.nature.com/news/earth-science-how-plate-tectonics-clicked-1.13655 – printed on the 50th
anniversary of the publishing of the definitive article on sea-floor spreading, by Fred Vine. Please listen to the
Podcast, if you’d like!
Let’s not forget Marie Tharp! Unfortunately, I didn’t seriously learn about her until I heard a Bob Edwards
interview of Hali Felt, who wrote her biography, entitled Soundings – a fascinating read. Here are a few links you
may find useful:
o Here’s a link to a New York Times video summarizing Marie’s obituary: http://nyti.ms/1cdkZlV
o Here’s a link to an hour-long talk by Hali Felt, at Columbia University: http://vimeo.com/53380314
and here’s a link to a PDF of the PowerPoint used in the Hali Felt talk: http://online.geologyguy.com/pdfs/gebco_sixth_science_day_felt2.pdf
o And here’s a PDF of the obituary that started it all: http://online.geologyguy.com/pdfs/MarieTharp_NYT.pdf
Part 2. Cascade Mountains (including Mt. St. Helens) — an example of Andean Plate Boundary
I have a special affinity for this volcano, since I had volcanic ash fall on my head some 550 miles to the east, at the edge
of Yellowstone National Park (itself a “super” volcano!). That was Sunday evening, 18 May 1980, before most of you
were born, I assume. I was driving back from a geology meeting in Utah, where I had listened to talks by USGS scientists
describing the volcanic activity which had just begun two months earlier. I had not heard that the Mountain had erupted,
because there was no radio reception along the way, through the mountains of Utah, Idaho, Wyoming and Montana. I
was quite surprised when ash began to fall from the sky and show up in my headlights!
The Google Earth image above shows how far the volcanic ash travelled in about 12 hours! The red triangles on the map
are active volcanoes, and the yellow dots are earthquakes that occurred in the previous week.
USGS Publication: Eruptions of Mount St. Helens: Past, Present, and Future:
Link: http://vulcan.wr.usgs.gov/Volcanoes/MSH/Publications/MSHPPF/MSH_past_present_future.html
th
Links to several videos which will give you more of a feel for the power that was released on May 18 , 1980!
NOVA – Mt. St. Helens: Back From the Dead (not closed captioned, but a transcript is available in “Videos”) http://www.pbs.org/wgbh/nova/earth/mt-st-helens.html
the following are closed captioned, on my YouTube channel (you’re welcome!)
Eruption of Mount St. Helens, 1980 (released in 1981) – http://youtu.be/Jn52OAPK8nI
Mount St. Helens: May 18, 1980 (30th anniversary video) – http://youtu.be/_CrBp9KWY0o
Mount St. Helens: A Catalyst for Change – http://youtu.be/6g927Z54E0Q
This link will take you to the part of the USGS Volcanic Hazards Program website that summarizes the major types of
volcanic hazards: http://volcanoes.usgs.gov/hazards/ Note the links to the main types of volcanic hazards:
Volcanic Gases
Volcanic Gas and Climate Change
Air Pollution
SO2 Aerosols
Lahars
Pyroclastic Flows
Volcanic Landslides
Lava Flows
Tephra