SCIENCE GRADE 10 1st quarter

The two layers that the Earth's lithosphere consists

•crust

•upper mantle

Crust

Outermost layer of the earth or the thinnest layer

2 types of crust

Oceanic Crust- locates in the bottom of the water

Continental Crust-locates in the surface

asthenosphere

The denser weaker layer beneath the lithospheric mantle

plate tectonics

The movement of plates

Compositions of Oceanic crust

•Basaltic rocks composed of silicates and magnesium (“SiMa”)

•Mafic rocks

•Density—2.9g/cm³

•Age-oldest are less than 200 million years old

•Coverage- 29% of the Earth’s surface

•thinner but denser

Compositions of Continental Crust

•Granitic rocks composed of silicates and aluminum (“SiAl”)

•Felsic rocks

•Density-2.7g/cm³

•Age- 3.8 billion to 4 billion years old

•Coverage- 71% of the Earth's surface

•Thicker but less dense

Difference between focus or hypocenter to epicenter

Focus- where earthquake origates

Epicenter- lies above the focus

How can we get the time difference?

time difference formula

formula for the computed distance on the map (cm)

Identify and describe the 3 types of boundaries

The location where two plates meet

3 types of plate boundaries

•Convergent plate oundaries- occurs when two plates come together; Happens in oceanic-continental, oceanic-oceanic, continental-continental

•Divergent plate boundaries- occurs when two plates move apart

•Transform fault boundaries- slide past each other horizontally

Geological events that occur in convergent plate boundaries

•Oceanic-continental

-Subduction

-Volcanic arc

-Trench/Submarine Valley

-Earthquake

•Oceanic-Oceanic

-Subduction

-Volcanic Arc

-Trench

-Earthquake

-Tsunami

•Continental-Continental

-Mountain formation

-Earthquake

Geological events that occur in divergent plates boundary

•Oceanic ridge

•Rift Valleys

•Earthquakes

Geological events that occur in transform fault boundaries

•Fault lines

•Earthquakes

Types of earthquakes

•Shallow earthquakes

-focus is within 60 km and 85% energy released

•Intermediate earthquakes

-60-300 km and 12% energy

•Deep earthquakes

-300-700km and 3%

Who introduced the idea of transform plate boundaries?

John Tuzo Wilson

What is conservative type?

The lithosphere is not destroyed but rocks are displaced along the shearing zone

conservative type

The lithosphere is not destroyed but rocks are displaced along the shearing zone

shear zone

Where shallow earthquakes happen frequently