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Vocabulary

I.

I. Evidence of Crustal Changes A. Deformed Rock Structure - Sedimentary strata normally form in a _______________

___________________. Any change from the horizontal position is evidence of

_____________________________________________________________________.

1. Strata 2. Strata

3. Strata

Unit 4: Dynamic Crust – Earthquakes, Volcanoes & Earth’s Interior

Anticline Asthenosphere Compression Continental Crust Continental drift Convection Cell Convergent Boundary Crust Crustal plate Divergent Boundary Earthquake

Epicenter Fault Focus Fold Fracture Hot spots Inner Core Island-arc Lava Lithosphere Long wave or L-wave Magma

Mantle Mid-ocean ridges Moho Discontinuity Oceanic Crust Outer Core Pangaea Plate Tectonics Primary or P-wave Richter scale Ring of Fire Rift Valley

Sea floor spreading Secondary or S-wave Seismic wave Seismograph Shadow zone Subsidence Syncline Subduction Transform Boundary Tsunamis Volcano


B. Fossil Evidence

1. Marine fossils found at high elevations suggest

_________________________.

2. Shallow water marine fossil found at

great ocean depths suggest

__________________________________.

II. Plate Tectonics

1.

a. T

The crust contains both __________________________________ which

is covered by our planet’s oceans, and ___________________________

_________________ that is the land on which we live.

2. Earth’s Surface – a. Label the diagram.

3.

2.

1.

4.

5.

6.

1. Crust: __________________km thick

Density = ________________

2. Mantle: __________________km thick

Density = ________________

3. Outer Core: __________________km thick

Density = ________________

Inner Core: __________________km thick

Density = ________________


b. Density of: 1. Ocean (water) _______________

2. Granite (continental crust) _______________

3. Basalt (ocean crust) _______________

4. Rigid upper mantle

5. Asthenosphere

c. Lithosphere = __________________ + ____________________________

d. – The plastic-like layer below the lithosphere in the Earth’s upper mantle.

3. Theory of Continental Drift

a. – proposed the theory of Continental Drift in the early 1900’s.

b. He proposed that approximately 200 mya, all the continents existed as one large land mass which

he called _______________________.

Evidence of continental drift:

1. Coastline of the continents – for example, the east coast of _______________________________

fits well with the west coast of _______________________________ – like the pieces of a giant

.

2. Fossil Clues – certain fossils of

___________________________ are found on

widely separated continents.

Mesosaurus was a small freshwater reptile. It’s

fossils are found in and

Glossopteris – it was an ancient seed-fern (with

very large heavy seeds). It’s fossils are found in _________________, India, Australia, Antarctica

and .


3. Rock Clues:

a. The _______________________________ Mountains of the eastern US are geologically similar

to the mountains in Greenland and Western Europe, which include the Caledonian Mountains of

Scotland.

b. Structure, age, and mineral content of rocks are similar on the coasts of eastern

________________ __________________________________________________.

4. Climate Clues:

a. Coal, which forms from plants that grow in warm swampy environments, is found today in the

colder climates of ____________________________________________________.

b. __________________________________, containing the remains of coral, which once lived in

_________________________, is found today in northern latitudes such as .

c. Ancient rocks of the __________________________ near the equator in South America, South

Africa and other southern landmasses show evidence of _______________________________.

4. Theory of Sea Floor Spreading

A. Topography of the ocean floor

Label the following on the diagram.

1. Seamount

2. Abyssal plain

3. Rift-valley

4. Mid-Ocean Ridge

5. Trench

6. Continental Slope

7. Continental Shelf

B. Evidence for Sea Floor Spreading

1. Age Evidence – As the distance from the ocean ridge

the age of the rock

.

2. – magnetic clues

from the iron-bearing basalt rock of the ocean floor supports

the theory of seafloor spreading.

(add the magnetic field arrows to this picture)


C. The Theory of Sea Floor Spreading

1. The Theory of Plate Tectonics states that Earth’s (crust + upper

mantle) is divided into sections called .

Key to Major Plates

1. North American

2. South American

3. Eurasian

4. African

5. Pacific

6. Nazca

7. Antarctic

8. Indian-Australian

2. – The theory of Plate Tectonics states that these

lithospheric plates are in motion and “float” or ride on the _____________________________.

3. Direction of Plate Movement – the movement and interaction of tectonic plates creates 3 types of

plate boundaries: the arrows on the tectonic map below show the relative motion.


4. Types of Plate Boundaries

A. Divergent Plate Boundaries – .

1. _________________: Mid-Atlantic Ridge

2. Continental –

B. Convergent Plate Boundaries –

________________________________________________________.

1. Oceanic-Continental – _____________________________ ________________

Example: Nazca (oceanic) subducts under South American (continental)

2. Oceanic – Oceanic –

______________________________

_______________________ of

Japan and Alleutian Islands (Alaska)

3. _______________________ - _________________________ – Indian/Australian Plate

Colliding with Eurasian Plate forming the

Himalaya Mountains

C. Transform Plate Boundaries –


D. Convection Currents = ___________________________________________________________

Hot, ______________dense material from deep within Earth’s mantle rises. When this material

cools near the surface, it becomes ____________ dense and sinks. The resulting convective flow

of this material in the mantle ___________________ /_______________ lithospheric plates across

the surface of Earth.

III. Earthquakes

A. ______________________________ – the branch of science that studies earthquakes.

B. Causes of Earthquakes – __________________________________________________________

_________________________________________________________________________________.

1. Plate Boundaries

Divergent Boundary -

Convergent Boundary – Ocean –Continent -

Convergent Boundary – Ocean – ocean -

Transform Boundary – (Strike-Slip Fault) -

C. Earthquakes tell us about Earth’s surface movement.

Key:

= within 75 km of Earth’s

Surface

= 75 – 300 km

= 300 – 700 km


D. Earthquakes cause other disasters

Tsunami =

Characteristics: Speed =

Height =

Features formed by tectonic activity

1.

Faults

2. Earthquake Waves and Earth’s Interior

a. Origin and map location

___________________ = Point beneath Earth’s surface where fault movement releases seismic

waves (energy)

____________________ = the point on Earth’s surface directly above the focus.

b. Types of seismic waves

1. Analysis of seismic waves (P and S waves) has led scientists to infer the

of Earth.

2. P Waves

P or Primary Waves- Also known as

waves -

Motion of matter due to P waves-

alternate contraction and expansion

of rocks in a direction parallel to the direction of wave propagation.


3. S Waves

S or Secondary Waves- Also known as

Motion of matter due to S waves-

displacement of adjacent rocks in a

direction to the direction of wave propagation.

The velocity of P and S waves is controlled by how the material through which wave is

traveling responds to shear forces. It also depends on the of the

material.

4. L-Waves

_________________ are

___________that cause horizontal

shifting of the Earth during an

________________

C. Seismograph –

D. Locating the Epicenter

Using Seismic Waves to Study Earthquakes

1. Need at least stations

2. Determine when P wave arrives

3. Determine when S wave arrives

4. Difference between S and P wave arrival ( t)

5. Locate on travel-time curve what the ( t) corresponds to in distance

6. Draw circles around each station with radii=distance just determined

7. Intersection of three circles is the epicenter


E. Earthquake Waves

• Seismic Waves travel through the entire Earth

• Travel at different rates through different !

• That’s why the lines “ ”…….when they go through the layers

• Earth’s structure/interior is divided into the crust, mantle, outer core and inner core.

F. Measuring an Earthquake

1. Richter Scale –

.

(Each of the numerical steps represents a 10-fold increase in the amount of energy; for

example, a reading of 3 indicates 10 times more energy than a reading of 2)

Earthquake Severity

Richter Earthquake Magnitudes Effects Less than 3.5 Generally not felt, but recorded. 3.5-5.4 Often felt, but rarely causes damage. Under 6.0 At most slight damage to well-designed buildings. Can cause major damage to poorly constructed buildings over small regions. 6.1-6.9 Can be destructive in areas up to about 100 kilometers across where people live. 7.0-7.9 Major earthquake. Can cause serious damage over larger areas. 8 or greater Great earthquake. Can cause serious damage in areas several hundred kilometers across.

2. Mercalli Scale –


IV. Volcanoes

A. Volcanic

Regions on Earth

Ring of Fire =

B. Causes of Volcanic Activity

1. ____________________ - island arc volcanoes (Aleutians), subduction (Cascades, Andes)

2. Hot Spots –


C. Types of Volcanoes

D. Volcanic Features