L.O: DYNAMIC CRUST, EARTHQUAKES, EARTH’S INFERRED INTERIOR & PLATE TECTONICS.

The crust is the outer-most layer of the lithosphere.

• Most of the crust is made of two elements oxygen and silicon.

• There is two kinds of crust: continental and oceanic.

• Continental crust is felsic, made of granite, thicker and low density (2.7g/cm3)

• Oceanic crust is mafic, made of basalt, thinner, high density (3.0 g/cm3)

The crust is the outer-most layer of the lithosphere.

• page 1 of ESRT has info about crust’s composition.

• page 1 of ESRT has info about crust’s composition.

• Complete page 42-43 in your workbook.

The crust is dynamic, constantly changing.

The Earth’s crust has many fault zones-cracks in its surface.

Most of Earth’s crustal activity happen around the fault zones.

earthquakes, mountain-building and volcanoes all happen around the fault zones.

The rock strata of EARTH’S crust continually changes

The rock strata of EARTH’S crust undergoes tilting, folding, faulting, uplift and subsidence

faulting

folding

On the regents I will sequence rock layers

I must be able to tell which event happened when.

EARTHQUAKES

EARTHQUAKESIS A SUDDEN MOVEMENT OF EARTH

ALONG A FAULT OR BREAK IN THE EARTH.

SEISMIC (EARTHQUAKE) WAVES ARE GENERATED WHEN AN EARTHQUAKE HAPPENS.

P-WAVES AND S-WAVES ARE GENERATED WHEN EARTHQUAKES HAPPEN.

P-WAVES travel faster than S-WAVES. Thusly, P-WAVES always arrive first to an earthquake detection station.

The difference between the P-WAVES an S-WAVES arrival times is used to determine the earthquake’s epicenter.

12 minutes – 6 minutes= 6 minutes.

Three seismograms are used to triangulate the location of an earthquake’s epicenter.

Open your workbook to page 122.complete the questions.

The inferred properties of the Earth’s interior.

The interior properties of Earth’s interior are inferred from studying .

• Seismic wave behavior• The composition of meteorites

P-waves can pass thru solids and liquids. S-waves solid only.

The outer core is inferred to be liquid because of the shadow zones, where no S-waves are detected.

COMPLETE PAGE 115-121

PLATE TECTONICS:

The theory of continental drift says that the continents have moved into their present

evidence of continental drift (crustal plate motion).

• The continents look like a jigsaw puzzle.• Rock layers and fossil on different continents

match.• Sea floor spreading

The theory of plate tectonic explains earthquakes, volcanoes, mountain ranges and

the cause of continental drift.

The Earth’s crust is made of huge plates that move.

Movement at the plates cause earthquakes, volcanoes, mountains

and continental drift.

The crustal plates can move in three ways: (three kinds of boundaries between plates)

Convergent plate boundary (subduction zone)

Subduction zone (convergent boundary)

Subduction zone (convergent boundary)

Two transform plate boundarys

Seafloor spreading: why the continents drift

At the mid-atlantic ridge, new crust is being created. The new crust pushes away old crust.

As the old crust is pushed away, the continents are pushed too.

the oldest crust is at the continental shelf, the youngest crust at the mid-atlantic ridge..

Evidence of new seafloor formation is the alternating pattern of reverse and normal polarity of mineral

alignment in the seafloor crust.

Convection currents in the Earth’s asthenosphere power continetal drift ( earthquakes, plate tectonics etc0

Complete page 65 of green workbook