Earth from space (©NASA)

The earth is dynamic.

The processes that have shaped the earth as we know it today are perpetual on a geologic time scale.

Earth cross-section

Geologic history• Continental drift

Geologic history• Plate tectonics

Divergent boundaries

Convergent boundaries

Transform boundary

Hotspots

Lithospheric (tectonic) plates

Earthquakes

• Defined as the shaking of ground caused by a sudden release of energy from rocks underneath

• A fault is a break between two rock masses

Earthquakes• Average length of time: 10-30 seconds• Measured using the Richter Scale

• May cause tsunami waves– Submarine earthquakes– Explosive volcanic eruptions– Submarine landslides– Terrestrial landslides that enter water bodies– Impacts of large extraterrestrial objects (e.g. asteroids or comets) in the ocean

Tectonic Setting of Earthquake of 26 December 2004 from United States Geological Survey(http://earthquake.usgs.gov/eqinthenews/2004/usslav/)

Earthquake caused by subduction of Indian plate beneath the Burma microplate

Relative motion of Indian plate to Burma microplate = 0.06 m per year (2.4 inches per year)

Areas potentially affected by tsunami inundation and run-up in yellow(i.e. shore zones < 20 m above sea-level)

Areas Potentially Affected by Tsunami of 26 December 2004 from UNOSAT(www.unosat.org)

Volcanoes

Ring of Fire