WSUGPH2200Ch13Ch15questions-1.docx

WSUGPH2200Ch13Ch15questions-1.docx - Alexis McCoy...

This preview shows page 1 - 3 out of 5 pages.

Alexis McCoy Instructor: Dr. Dennis Burin Using bullet points, list 5 important facts per question Ch. 13 Evolution of the Great Lakes 1.Discuss the origin and the development of the lake basins. 2. Discuss glaciers and lakes. The Laurentide ice sheet is used to describe the continental glacier whose center was at Hudson Bay. The Cordilleran ice sheet was formed north of the Rocky Mountains. The farthest extent occurred during the Last Glacial Maximum. The pull back of the LGM did not proceed from long and steady, but it was uneven and punctured. This was confusing and complicated, but the events led to numerous proglacial and post- glacial lakes within each Great Lakes basin. 3. Discuss radiocarbon vs. calendar years. (Focus Box) Radiocarbon years and calendar years express different ages for the same geologic event. Radiocarbon isotope carbon has a half-life. Determining radioactivity in dead organisms allows us to approximate the elapsed time since it died. Dendrochronology is the study of determining the age of trees and ancient wooden materials. A calendar year is constant, while radiocarbon years can vary over time. 4.Discuss the early lakes of the Lake Erie/Huron basin. 5. Discuss Isostatic rebound. (Focus Box) Ancient shorelines of glacial and post-glacial Great Lakes phases are often not at the same elevation at which they formed. The rigid lithosphere “floats” on top of the viscous asthenosphere. Glacial isostasy is adding glacial mass which depresses the lithosphere into the asthenosphere.
Image of page 1

Subscribe to view the full document.

Conversely, the melting glacier causes the opposite and it bounces back. The asthenosphere doesn’t react quickly to glacial loading and unloading; its lagged.
Image of page 2
Image of page 3
  • Fall '18
  • Dennis Burin
  • Geography, Great Lakes

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern