Science Notes The Lithosphere

Read: Chapter 13

The Lithosphere. 

Top 3 crust elements:

1. Oxygen
2. Silicon
3. Aluminum

• ·  Proposed by Alfred Wegener
• ·  Single Super Continent – Pangaea
•   o       Evidence
•     §         Rock types and landforms
•     §         Ancient Climates – continents in different locations
•     §         Living plants and animals
•     §         Fossils
•     §         Sea-floor spreading
• ·  Continental Drift separates the continents
•   o       Movement about 5cm /yr (same as human fingernail growth) 

• ü           Theory that the Earth’s lithosphere is composed of many plates of different shapes and sizes
• ü           Plates are moved by convection currents.
• ü           3 types of plate boundaries
•      o       Spreading
•      o       Convergence
•      o       Transform 

• ·  Spreading Zones
•     o       Largest is Mid-Atlantic ridge
•     o       64000km
• ·  Convergence
•     o       Ocean / Continental Boundary
•      Ø      Crust destroyed
•      Ø      Ocean subducted under continent
•      Ø      Melted rock might erupt as volcanoes
•     o       Continent / Continent Boundary
•      Ø      Plates fold up
•      Ø      Creates mountains
• ·  Transform
•     o       Plates slide past
•     o       Stress builds up when they stick together
•     o       Sudden release causes earthquakes
•     o       Famous boundaries include San Andreas Fault in California 

Earthquakes.

Earthquakes are ___________________ caused by sudden movement of the Earth’s plates along a ________________.The spot where the break or _______________ occurs is called the ____________.Directly about the focus, on the surface of the Earth is a point called the ________________.Energy in the form of four types of ____________ begin at the epicenter and move through the material of the Earth.________________ move in a series of compressions and stretches in the ______________ direction as the wave. These waves are the first detected on a _________________ as they travel the fastest. __________________ move at right angles to the wave, are ____________, and can’t travel through fluids such as ________________ or ___________________. The two other waves are called L and R waves. Geologists who study earthquakes are called _____________________.They measure the ______________ of the wave and its _______________ to the epicenter to calculate the _______________.Seismologists use __________________ to find the earthquakes epicenter.The Ring of Fire, along the edge  of the ________________ ocean experiences ___________________ of all earthquakes. 

Humans and Earthquakes.

About _______________ earthquakes a year are NOT felt by humans. Between ____and ____ earthquakes per year are large enough to cause SERIOUS damage. Aftershocks from a major earthquake can last for weeks. Trying to predict earthquakes is expensive and inaccurate.Major Earthquakes.Shensi, China (1556), 830’000 people killed.San Francisco, CA (1906), ¾ of the city destroyed by fires, 700 people died.Prince William Sound, AK (1964), caused landslides, avalanches and tsunami.Measuring Earthquakes.The ­­­­­­­­­­­­­____________ scale is based on damage to man-made structures (I to XII).The ____________ scale measures exact amount of energy released, each level is ten times bigger than the previous level. (0 to 10)Remote Sensing Technology.Satellites and airplanes are used to take images of surface features to predict what is under the surface. Remote sensing is used to locate specific __________ and map fault lines. 

Faults

3 types. Draw a picture of each using the model you made.

1. Normal fault
2. Reverse Fault
3. Strike Slip Fault

Read Chapter 14.

Rocks and Minerals.

• Rocks are made up of 1 or more minerals.
• Minerals are naturally formed soilds, that have a definate chemical composition and crystal structure.

A mineral is determined by its chemical composition and crystalline structure.

Properties to look for:

• Color - never identify based on color alone
• Hardness - the resistance to being scratched
•               - Measured on Moh's scale 1 = talc (soft), 10 = diamond (hard)
•               - Hard minerals can scratch soft minerals
• Cleavage and Fracture - minerals can break in 2 ways
•               - Cleavage - when you get a mini version of the original
•               - Fracture - you get irregular shapes when broken.
• Density - different minerals have a different mass, even when they have the same volume
• Crystal form - crystals form as minerals cool.
•               - the pattern of crystals is based on the way atoms are arranged.
• Streak - the color of the powder left behind
•               - streak is not always the color of the mineral