Untitled Flashcards Set

1. What was Wegener’s theory and why was it accepted/rejected?

→ theory of continental drift

Wegener’s theory states that the continents used to be one supercontinent of Pangea, and supports ideas of continental drift. It was rejected because there wasn’t evidence to support it but there is evidence of seafloor spreading

2. What is seafloor spreading and the lines of evidence?

Seafloor spreading is the idea that as new crust is created at mid-ocean ridges at divergent plates, the other end of the plate is being destroyed bc lithosphere is sinking into subduction zone

Lines of evidence include fossils, glaciers, and rocks. They were discovered along coastlines of continents now far away from one another, and support the theory of plate tectonics.

3. How can we use seismology to learn about the internal structure of the Earth?

Seismology: study of earthquakes and seismic waves. Studying how seismic p-waves and s-waves reflect and interact with the deep layers of earth reveal the composition of each layer. P-waves can pass through all volumes, wile s-waves can only pass through liquid.

4. What is the internal structure of the Earth and its characteristics?

Crust - solid

Mantle - solid, responsible for movement of tectonic plates in asthenosphere

Core - solid inner core, liquid outer core responsible for earth’s magnetic field

5. What are the basic types of plate boundaries?

Divergent - seafloor is created, shallow earthquakes, volcanic activity, ridges + rifts

Convergent - seafloor is destroyed; shallow and deep earthquakes, volcanic activity, mountains + trenches

Transform - seafloor neither created or destroyed, shallow earthquakes

6. What is isostasy and how does it relate to mountain building?

Isostasy is the concept that thicker, more buoyant crust will float to the top and weigh down thinner, denser crust. It’s crucial to mountain building because it gives mountains height, making them topographically higher.

7. What is Earth System Science and the 5 spheres?

The study of earth as an interconnected system

Geosphere, Biosphere, Atmosphere, Anthroposphere, lithosphere

8. What are magnetic stripes and what do they mean?

Magnetic stripes are symmetrical and alternating magnetic anomalies (high/low magnetism stripes) along the seafloor, usually mid atlantic ridges*

Key piece of evidence supporting theory of plate tectonics and process of seafloor spreading

9. What are subduction zones, mid-oceanic ridge, and hot spots?

Subduction zone: where a plate subducts beneath another due to differences in density convergent boundaries

Mid-ocean ridge: underwater mountain range formed at divergent plate boundaries where new seafloor is created

Hot spots: area of mantle where heat from deep earth causes volcanic activity, independent of plate movements