Map showing the movement of Earth's tectonic plates.
The Australian plate is moving northwards at 10cm per year and in millions of years will crash into Asia.
Image: Illustrator Gary Hincks
Source: Photolibrary
Earthquake damaged building in Maipu, Chile after 27 February 2010 earthquake.
The pattern of earthquakes around the globe shows us the edges of Earth’s tectonic plates. While there are earthquakes in the middle of plates, the quakes at the plate boundaries are much more intense and frequent.
Image: Jorge Barrios,
Source: CC-BY-SA 3.0, Wikipedia
San Andreas Fault in the Carrizo Plain, aerial view from 8500 feet altitude.
The San Andreas Fault stretches over 1000 km through California where the Pacific and North American tectonic plates meet. It has caused several historic earthquakes including the 1906 San Francisco quake.
Image: Ian Kluft 2007
Source: CC-BY-SA 3.0, Wikipedia
Quartzite, Cave Hill quarry, Lilydale, Victoria, Australia
Rocks are folded and faulted by immense forces generated by the collision of Earth’s tectonic plates. Folding and faulting occurs on a vast scale, as in fold mountains such as the Himalayas and the San Andreas Fault in California. The effects can be seen in individual rocks such as these sheared and recemented white quartzite pebbles.
Image: Rodney Start
Source: Museum Victoria
The Earth’s surface is made up of large plates which are constantly moving, driven by the internal heat of the planet. At the edges of plates, mountains form, volcanoes erupt and earthquakes fracture the crust, creating ever-changing landscapes.
The Earth’s tectonic plates are 100 to 200 km thick. They consist of the crust and the uppermost part of the mantle (the lithosphere). The plates slide across the more fluid part of the upper mantle (the asthenosphere). Plate boundaries are zones of intense earthquake and volcanic activity.