Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 1: Living with Tectonic Hazards (Gateway 1: Tectonic Plates…
Chapter 1: Living with Tectonic Hazards
Gateway 1: Tectonic Plates
Structure of Earth
Core (3500km, 3000~5000ºC)
Solid
Inner Core (1400 km)
Liquid
Outer Core (2100 km)
Mantle (2900 km, 800~3000ºC)
Lower Mantle
Upper Mantle
Uppermost Mantle + Crust = Lithosphere
Crust
Oceanic Crust (Dense Basalt, 5~8 km)
Continental Crust (Less dense Granite, 35~70km)
Movement of Tectonic Plates
(different types of plate boundaries)
Divergent
Plate Boundary <->
O-O Oceanic-Oceanic Divergence
Mid-Oceanic Ridge
Volcanic Islands
Mid-Atlantic Ridge
(North American, Eurasian)
C-C Continental-Continental Divergence
Rift valleys and Block Mountains
East African Rift Valley
(Nubian-African, Somalian-African)
Convergent
Plate Boundary >-<
O-O Oceanic-Oceanic Convergence
Deep Oceanic Trench
Volcanic Islands
Mariana Trench and Mariana Islands
(Pacific subducts under Philippine)
O-C Oceanic-Continental Convergence
Deep Oceanic Trench
Volcanic Islands
Fold Mountains
Sunda Trench and Barisan Mountains
(Australian subducts under Eurasian)
C-C Continental-Continental Convergence
Fold Mountains
Himalayas and Tibetan Plateau
(Indian subducts under Eurasian)
Transform
Plate Boundary ▲▼
San Andreas Fault, Southern California
(North American and Pacific)
Why do tectonic plates move?
Convection Currents
Slab-pull Force
Gateway 2: Landforms and Tectonic Phenomena
LANDFORMS
Fold Mountains
Upfolds (Anticline)
Downfolds (Syncline)
Folding is more common in
sedimentary rocks
compared to (igneous rocks, metamorphic rocks)
Convergent Plate Boundaries with Continental Plate involved
Himalayas, Tibetan Plateau, Barisan Mountain, Andes Mountain
Rift valleys and Block mountains
C-C Divergent Plate Boundary
1) East African Rift Valley
2) Vosges in France & Black Forest in Germany separated by Rhine Valley
Volcanoes
Shield Volcanoes (e.g. Mount Washington, USA)
Low Profile, Gentle Slope
Low-silica lava (Low Viscosity), gases
escape
easily
Less explosive in nature
Straotovolcanoes (e.g. Mount Mayon, Philippines)
High Profile, Steep Slope
High-silica lava (High Viscosity), gases
trapped
easily
More explosive in nature
PHENOMENA
Earthquakes
FORMATION
: Slow buildup of stress on the rocks found on either side of the fault. When rocks can no longer withstand the increasing stress, they can suddenly slip, causing an earthquake.
PROPERTIES
: Focus, Epicentre, Seismic Waves, Aftershocks
Factors affecting
extent of damage
of earthquake
Population Density
Level of Preparedness
Distance from epicentre
2011 Christchurch, New Zealand [nearer to epicentre, more destruction]
Time of occurence
1999 Sun Moon Lake Region, Taiwan [earthquake at midnight]
Type of Soil (Liquefaction)
2011 Christchurch, New Zealand [abandoned houses due to liquefaction]
Risks
associated with living in earthquake zones
Tsunamis
In 2004, 9.2-magnitude earthquake, Indian Ocean, affected coastal communities in 12 different countries
Disruption of services
In 2004, Kobe, Japan, damaged pipes and transmission lines disrupted electricity, gas and water supplies to many Kobe residents.
Landslides
In 1970, the Peru earthquake destabilised the slopes of Mount Huascaran, causing a massive landslide that killed 18,000 people.
Destruction of properties
In 2011, Tohoku, Japan earthquake, several shortage of homes due to a produced tsunami 10km inland destroying homes
Destruction of infrastructure
In 1995, Kobe, Japan, roads and bridges were damaged, and many places were inaccessible or difficult to reach.
Loss of lives
In 2011, Tohoku, Japan earthquake, 28,000 lives were lost due to the earthquake being of 9.0 magnitude on Richter Scale.
Volcanic eruptions
Risks of living near volcanic areas
Massive destruction by volcanic materials
Pollution
Benefits of living near volcanic areas
Fertile soil
Precious stones and minerals
Tourism
Geothermal energy
Gateway 3: Preparation and Response to Earthquakes