Introduction 1-3 Flashcards
Continental Rock average denisity
2.7 tonnes/m3
Earth Density
5.52 tonnes/m3
Iron density
13 tonnes/m3
Depth of Core
2890km
Types of body waves (2)
P - Primary/Compressional
S- Secondary/Shearing
What Type of earthquake wave cannot pass through liquids?
S-Waves
Composition and State of Outer Core
90% Iron-Nickel
10% Light material
Liquid
Name of Boundary between Crust and mantle
Mohorovicic Discontinuity
Depth of Mantle
25-90km below Continental
6-11km below Oceanic
How do plates move if the mantle is solid
Solid state convection
What is Isostasy?
Crust floating in equilibrium above the mantle
state of gravitational equilibrium between Earth’s crust and mantle such that the crust “floats” at an elevation that depends on its thickness and density. This concept is invoked to explain how different topographic heights can exist at Earth’s surface
Describe crust compositions (Rock-type, Density, Material)
Continental: Granitic, 2.7g/cm3, Silica-rich
Oceanic: Basaltic, 3g/cm3, less but still Silica-rich with more iron, magnesium and calcium
Mantle composition
Peridotite, 3.3g/cm3, High in Magnesium and Silica
Depth of inner core
5155 km
What is the Asthenosphere
- Region of the upper mantle
- Below the lithosphere, 80 and 200 km depth
- Slowly solid-state connects
- Mechanically weak and ductile