ch3_tectonics - Plate Tectonics and Earthquakes Natural...

Info icon This preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Plate Tectonics and Earthquakes Natural Disasters, 6 th edition, Chapter 3
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Plate Tectonics and Earthquakes Gujarat, India , January 26, 2001: Major earthquake great natural disaster Event so destructive that outside help is needed 20,103 people killed, deadliest natural disaster of 2001 Figure 3.1 Turkey , August & November, 1999: Numerous building failures (similar to India) More than 19,000 people killed
Image of page 2
Amos Nur, earthquakesandarchaeology.smugmug.com
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
1700 Cascadia Earthquake Magnitude of 8.7 to 9.2 - carbon dating of local tsunami deposits.
Image of page 4
Seismic x-section cascadia here ... Andrew Calvert, 2004, Nature
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Plate Tectonics Tectonic cycle: Melted asthenosphere flows upward as magma Cools to form new ocean floor ( lithosphere ) New oceanic lithosphere (slab) diverges from zone of formation atop asthenosphere ( seafloor spreading ) When slab of oceanic lithosphere collides with another slab, colder, denser slab subducts under less dense slab Subducted slab is reabsorbed into the mantle Cycle takes on order of 250 million years
Image of page 6
Plate Tectonics Tectonic cycle: Figure 3.2
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Plate Tectonics Lithosphere of Earth is broken into plates Plate Tectonics: Study of movement and interaction of plates Zones of plate-edge interactions are responsible for most earthquakes, volcanoes and mountains Divergence zones Plates pull apart during seafloor spreading Transform faults Plates slide past one another Convergence zones Plates collide with one another
Image of page 8
Plate Tectonics Lithosphere of Earth is broken into plates separated by: divergence zones, transform faults, convergence zones Figure 3.3
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Development of the Plate Tectonics Concept 1620: Francis Bacon noted parallelism of Atlantic coastlines of Africa and South America Late 1800s: Eduard Suess suggests ancient supercontinent Gondwanaland (South America, Africa, Antarctica, Australia, India and New Zealand) 1915: Alfred Wegener’s book supports theory of continental drift – all the continents had once been supercontinent Pangaea , and had since drifted apart Theory of continental drift was rejected because mechanism for movement of continents could not, at the time , be visualized
Image of page 10
Earth's magnetic f i eld 1950s, magnetometers adapted for marine from World War II submarine detection. Find odd magnetic variations across the ocean f l oor (basalt Fe rich). Noticed by Icelandic mariners late 1700s.
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Earth’s Magnetic Field Earth’s magnetic field acts like giant bar magnet , with north end near the North Pole and south end near the South Pole Magnetic pole axis is now inclined 11 o from vertical (tilt has varied with time) so that magnetic poles do not coincide with geographic poles (but are always near each other) Inclination of magnetic lines can also be used to determine at what latitude the rock formed Magnetic field is caused by dynamo in liquid outer core: Movements of iron-rich fluid create electric currents that generate magnetic field Figure 3.4
Image of page 12
Earth’s Magnetic Field Problematic details
Image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

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