http://www.windows2universe.org/earth/geology/quake_4.html
What is Pangea theory

What is the continental drift

Structure of the earth
What Is a Geologic Fault?
 A fault is a crack in the Earth's crust. Typically, faults are associated with, or form, the boundaries between Earth's tectonic plates.
 In an active fault, the pieces of the Earth's crust along a fault move over time. The moving rocks can cause earthquakes.
 Inactive faults had movement along them at one time, but no longer move. The type of motion along a fault depends on the type of fault.
 The main types of faults are described below.
Normal dip-slip fault
 Normal faults happen in areas where therocks are pulling apart
 Reverse dip-slip fault
Reverse faults happen in areas where the rocks are pushed together
(compression forces) so that the rocky crust of an area must take up less space.
Transform (strike-slip) faults
 The movement along a strike slip fault is horizontal with the block of rock on one side of the fault moving in one direction and the block of rock along the other side of the fault moving in the other direction.
Tectonic plates
 Are made of both continental and oceanic crust.
 Land that we see is the continental crust, about 30 kilometers (19 mi) thick.
 Under the sea, the heavier oceanic crust is much thinner, about 8 to 10 kilometers (5 to 6 mi) thick.
 Plates move about 8 centimeters (3 in) per year. That’s about as fast as a fingernail grows in a year!
 The tallest mountains in the world are still growing.
 About 60 million years ago, the Himalayan Mountains formed when the
Indian Plate crashed into the Eurasian Plate.
 Today the two plates are still colliding and the Himalayas continue to rise.
 Los Angles sits on the Pacific Plate that is moving northwest and San
Franciso sits on the
 North American Plate that is moving southeast.Moving towards each other at the rate of 5 centimeters (2 in) a year, someday these two cities may be neighbors!
How do plates move ?
 This image is a cross section through the Earth showing the convection cells of the mantle.
 Ridge push happens at spreading centers where plates are moving apart.
 A map of Earth's tectonic plates. Plate boundaries are shown in red.
 http://www.windows2universe.org/eart h/interior/how_plates_move.html

Slab pull happens at subduction zones where one plate is pulled down into the mantle.
 Plates at our planet’s surface move because of the intense heat in the
Earth’s core that causes molten rock in the mantle layer to move. ‘
 It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down.
 As the cooled material sinks down, it is warmed and rises again.
 Just like convection cells, plates have warmer, thinner parts that are more likely to rise, and colder, denser parts that are more likely to sink.
 New parts of a plate rise because they are warm and the plate is thin.
 As hot magma rises to the surface at spreading ridges and forms new crust, the new crust pushes the rest of a plate out of its way. This is called ridge push.
 Old parts of a plate are likely to sink down into the mantle at subduction zones because they are colder and thicker than the warm mantle material underneath them.
 This is called slab pull.
What is an earthquake?
 Earthquakes happen as large blocks of the Earth’s crust move suddenly past one another because of the force of plate tectonics.
 These blocks of the Earth’scrust meet at cracks called faults.
Sometimes those pieces do not slide smoothly past one another. There can be friction along the fault – jagged edges that snag the blocks of rock.
 This makes it difficult for them to move past each other. Sometimes they get stuck together temporarily. When the pieces of rock overcome the snags, energy is released.
 The release of energy causes shaking at the ground surface.
 The location inside the Earth where an earthquake begins is called the focus.
 The point at the Earth’s surface directly above the focus is called the epicenter.
 The strongest shaking happens at the epicenter.
What are seismic waves
 Seismic Waves: Moving and Shaking During an Earthquake
 During an earthquake, energy is released in seismic waves that travel from where the earthquake starts, a place called the focus.
 The seismic waves radiate from the focus.
 Seismic waves cause intense shaking at the Earth surface that can cause buildings and roads to collapse.
Ty pes of seismic waves created by an earthquake include P-waves and Swaves that travel throught the earth as well as surface waves, which can cause a lot of damage at the Earth's surface.
Scientific instruments for measuring Earthquakes
 Seismograph: A scientific instrument that measures ground movement.
Seismographs record shock waves using a scale of minutes vs. mm of amplitude
 Magnitude of earthquake intensity: The energy release (and destructive
 This diagram shows an earthquake along a fault. The focus of the earthquake is where the energy is released underground. T
 The epicenter is the spot on the
Earth’s surface directly above the focus.

power) of an earthquake. Earthquake magnitude can be measured by a
Richter scale.
 Earthquake intensity is most often measured using the modified Mercalli scale
3. An instrument used to detect and record earthquakes.
5. A sea wave that results from large-scale seafloor disturbances, caused often by large earthquakes.
6. A number describing the severity of an earthquake in terms of its effects on the earth's surface and on people.
10. A _________ wave is a seismic wave that travels along the earth's crust.
11. Scale used to define the magnitude of an earthquake.
12. This term is used to describe both sudden slip on a fault, and the resulting ground shaking.
13. How fast a point on the ground is shaking as a result of an earthquake?
1. The point within the earth where an earthquake rupture starts.
2. A number that characterizes the relative size of an earthquake.
4. The point on the earth's surface vertically above the point in the crust where a seismic rupture begins.
7. A fracture along which the blocks of crust on either side have moved relative to one another.
8. Earthquakes that follow the largest shock of an earthquake sequence.
9. An earthquake ______ is anything associated with an earthquake that may affect the normal activities of people.
10. The phenomenon felt by humans when an earthquake occurs.

 Aboriginal people used to light lots of small fires as they
 walked through the country.
 People knew where the
 firebreaks were: the burnt patches, sandhills, rivers, rocks,
 claypans and other things that stopped fire.
 They knew where
 there were sacred places, people’s camps, special plants and
 areas that shouldn’t be burnt.
 There are many varieties of trees, shrubs and ground covers which resist intense burning and/or have less chance of contributing to ember attacks.
 These plants have a number of
Australian Tress that are fire retardant
 Acacia cyclops Coastal Wattle
 Acmena smithii Lilly Pilly
 Banksia marginata Banksia
 Casuarina obesa Swamp Sheoak
 Eucalyptus sargentii Salt River Gum

distinguishable features, including a high salt and moisture content and a low volatile oil content in the leaves.
 Usually fire retardant trees have thick, welldefined bark and few branches which grow low to the ground.
 These trees and shrubs rarely shed large quantities of leaves and twigs and their seeds are usually enclosed in woody capsules