Chapter 2 Internal Structure of Earth and Plate Tectonics

Definitions from Natural Hazards 4th edition.

Plate Tectonics: process associated with the creation, movement, and destruction of these plates.  

• Australia is surrounded on all sides by both convergent and divergent boundaries and plates. 

Convergent: occur where plates move toward each other.

• Ocean-Continent where the oceanic plate sinks beneath continental plate
• Volcanic continental arc is formed (Earthquakes and Volcanic Activity)
• Great Earthquakes, explosive volcanoes, tsunamis, flooding, mass wasting

Divergent: occurs where neighboring parts of plates are moving away from each other.

• Ocean-Ocean spreading of two plates and molten rock (lava) rises up to fill the gaps. 



Divergent zone along the Antarctic Plate
to the SW and E. Slight Convergent zone
along the SE toward New Zealand. 

• Mid-Ocean ridge forms, new volcanic lithosphere is created. 
• Light to moderate earthquakes, nonexplosive volcanic eruptions

Convergent zone and the site of the famous
explosion of Krakatoa, Just to the NW of
Australia.

Seismic Activity map of Australia

Australia sits almost directly in the middle of the Indo-Australian Plate

 Picture Sources: https://www.pinterest.com/pin/366902700888546990/  

http://www.quakes.uq.edu.au/quakeinfo.html 

https://anakkrakatau-krakatoa.weebly.com/plate-tectonics.html 

https://en.wikipedia.org/wiki/Australian_Plate