Zusammenfassung der Ressource
Restless Earth
- Structure of the Earth
- Crust- A very
thin layer,
divided into
plates
- Upper Mantle-
Solid because it's
closer to the surface
of the Earth it's
cooler
- Lithosphere is Mantle and Crust.
Below the Lithosphere is very
viscous
- Asthenosphere is
Upper Mantle
- Core is Iron and Nickel.
Generates magnetic
field
- Inner core is
solid because of
pressure
- Oceanic more
dense, thicker
with Basaltic
rocks.
- Continental less
dense, thinner with
Continental rocks
- Plates
- Permian
(Pangea)
225 million
years ago
- Triassic
(Laurasia,
Gondwanaland)
200 million
years ago
- Laurasia Continents
Asia, North America,
Europe
- Constructive
in seas
- Destructive
on land
- Conservative
are random
- Constructive
(Divergent)-
Plates pull
apart
- Destructive
(Convergent)-
Plates push
together and
one subducts
- Collision-
Plates push
towards
each other
- Conservative-
Plates slide
past each other
- Volcanoes
- Landform erupting
lava through a
fissure in crust
- Measured on
Volcanic Explosivity
Index (VEI)
- Andesitic Magma-
Lower temp, high
number dissolved gases,
high silica content
- Basaltic Magma-
Higher temp, low
dissolved gases,
low silica
- High viscosity- Explosive!
- Shield Volcano-
Found at conservative,
basaltic lava, not
explosive
- Strato Volcano- Found at
destructive, andesitic
lava, explosive!
- Prediction- Tilt
meters, monitoring
gases
- Planning
(Evacuation, drills,
safe zones)
- Education (warning signs,
hazards, evacuation routes)
- Earthquakes
- Shaking of Earth's
crust, due to movement
of Earth's plates
- Plates get stuck, pressure
build up. When released
an earthquake occurs
- Releases
seismic waves
- Focus is inside the crust
where pressure is released.
Epicentre is point on Earth's
surface above the focus
- LEDC protection- Steel rod foundations,
cross braced wood or bamboo frames,
concrete rings tie walls to foundation
- MEDC protection- Cross
bracing, tuned mass
damper, base isolators
- Tsunamis
- Triggered by
earthquake in the
sea, displaces water
- MEDCs- Warning systems
- Reach
heights of
30m at
shore!
- At
Sea-
Small
Shore-
Big