Plate Tectonics
Tectonic plates are made up of what layer of earth?
The crust
Which types of plate boundaries cause earthquakes?
All types
Transforming
Converging
Divergent
Which plate boundaries create volcanoes?
Convergent
Divergent
Which plate boundaries create Tsunami's?
Mainly convergent boundaries
In what year was Latrobe affected by the flood?
2016
Two plates that slide past each other are which plate boundary?
Transforming boundary
What causes earthquakes?
Earthquakes are the release of built-up pressure between two plates at a boundary
What causes volcanic eruptions?
Build up of magma pressure in the upper layers of the mantle need to be released
What causes Tsnumais?
Underwater earthquakes cause a large displacement of water.
Risk = Hazard * Exposure * Vulnerability
What is the underlying driver of tectonic plate movement?
Convection cells
Differences in magma temperature, and therefore density in the mantle
What wording starting with M, measures the severity of an earthquake?
Magnitude
If two oceanic plates were converging together, what type of volcano would be created?
A volcanic island arc (volcano islands in the ocean, e.g. Hawaii)
How can you tell a Tsunami is about to hit your town?
Water at the shoreline will recede quickly.
OR
Early warning system announcement
How do flood levees reduce risk?
Flood levees reduce exposure by diverting water away from infrastructure and resources
True or False
Earth tectonic plates have remained the same shape and size since the creation of the earth
False
When hot spots from the core move, the plate boundaries shift, altering the shape and size of each plate.
Why doesn't Tasmania receive many earthquakes?
Tasmania is not located near a plate boundary
How fast does lava move at a divergent plate boundary
Typically, <0.1 m/s
How fast does a Tsunami wave move?
800-1000 km/hr
How do flood early warning systems reduce risk?
Early warning systems reduce the vulnerability of communities by giving emergency services as well as individuals a chance to prepare themselves
OR
EWS reduce exposure as they allow time for human populations to evacuate the area.
Why does oceanic crust subduct underneath continental crust?
Oceanic crust is denser than continental crust, meaning it is forced underneath at a convergent boundary
How often do earthquakes occur?
Magnitude 2 or smaller earthquakes occur over a hundred times a day.
Severe earthquakes (magnitude 8) occur once a year
How long do volcanic eruptions last?
Anywhere between hours and decades.
Most commonly volcanic eruptions last approximately 7 weeks.
How long does a Tsunami wave period last?
5 minutes - 2 hours
How do flood easements (buffer zones), reduce the risk of floods?
Easements reduce the exposure of assets to flood waters as they designate no valuable assets are to be placed there, AND they provide drainage for the water, slowing the flooding from reaching settlements