Earthquakes final

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Dynamics of the Earth

Do Now:You are a geology detective, you are taking a hike in the

Appellation Mountains upstate NY… you come across marine fossil in the bed rock and ask your self “How could Marine fossil be found so high in the bedrock… how did they get

here? Give an explanation in your notebook.

I. Evidence of Crustal Motions:

A. ________________ wears down the earth’s crust.____________ _______________ creates new mountains.

Weathering & Erosion

( Uplift )Plate tectonics

B. Sedimentary beds are

deposited as_______________

__(_____ _)

Horizontal Layers

Strata

THIS SEDIMENTARY STRATA SHOWS NO EVIDENCE OF UPLIFT OR CRUSTAL MOTION LAW OF

ORIGINAL HORIZONTALITY

C. Evidence of motions within

the Earth’s crust is indicated by:1._____________2._____________3._____________

TiltingFoldingFaulting

TILTING

FOLDING

FAULTING: OFF SET LAYERS

FAULTING

D. ______________provide direct

evidence of crustal movement.

Earthquakes

World Distribution

U.S . Distribution

_______ ______ and________ _______

are 2 changes thatcan be observed after

an earthquake.

Fault lines Uplifted land (displaced strata)

EARTHQUAKE DAMAGE

E. ______ ________are used in mapping surveys and indicate exact positions and

elevations.

Bench marks

Changes in ________________

of benchmarks are evidence that the

land is either ___________

or____________risingsinking

elevation

F.Displaced marine fossils found in mountains have 2

interpretations:

1. ____________________________________________________________

2. _____________________________________________________________

Higher sea levels covered mountains

Rocks were upliftedfrom a previous ocean bottom

G. _____________is the rising of the crust_____________

is the sinking of the crust

Uplift

Subsidence

II: EARTHQUAKES

1. The movement of ____________ inside

_______________

2. _______________ is the movement of rock along a surface where the rocks are broken.

A. 2 processes that cause earthquakes:

volcanoes

faulting

B. ________ movement of the crust over long periods of time builds ___________

within the rocks.

stress

Increased pressure causes the _______ _______

to break creating a ________.

Rock strata

When faulting occurs energy radiates through the earth as ________ ________ that cause the ground to_______________

Seismic waves

vibrate

III.Measuring the Earthquakes:

A. There are 2 scales to measure earthquakes:

1. ________________

2. ________________

Mercalli

Richter

B. _______________ scale is based upon the observations of people and damage caused. It

measures ___________ of the earthquake from____ to ____

Mercalli

intensity

Mercalli Scale – Intensity scale

C._______________

uses the seismograph to determine the ________________

Magnitude is the total______ released by the earthquake.

Richter Scale

magnitude

energy

Its numerical scale is ____ to ____.

Each of the numerical steps represent ____ increase.

Richter Scale – Magnitude scale

Do Now:

Read the Mercalli Intensity Scale and

the highlighted section of the script.

Let’s Use The Mercalli IntensityScale to Create

AnIsoseismal Map To Locate the

Epicenter of An Earth Quake

VIIIVII

V. Parts of the Earthquake:

A. The place underground where the break or fault occurs is the _______ of the quake.

Do Now:

Slinky Demo Time!!! Read over the Seismic Wave

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

Primary (p-wave

Secondary(s-waves)

Surface

Also called… (compressional, shear)

Causes the most damage…(Check one)

Relative Speed(Slowest, Fastest or Intermediate)

Describe the Wave Motion compared to the direction that the wave is traveling.

Bonus: In what layers of the earth can they travel?

The __________ is the location along the surface of the earth just above the focus where the earthquake is felt most strongly.

epicenter

A. The 2 most important energy waves are:

P-wave or Primaryand

S-wave or Secondary

P-wave

Primary Wave

S-wave

Secondary wave

B. Characteristics of Primary Waves (P)

waves: _______________________ _______________________

_______________________ _______________________

Faster than S wavesRecorded first

travels through both solids and fluids

C. Characteristics of Secondary Waves (S)

waves: _______________________ _______________________

_______________________

Slower than P wavesRecorded after P-wave

Can not travel

through fluids

TYPES OF EARTHQUAKE WAVES

D. Both S and P

waves travel faster through ___________

material.denser

Do Now:

Take out Chart from Slinky Demo. Finish it.

VI. Finding the Epicenter:

A. The seismograph records the ________________ and

________________________________________

magnitude

Records arrival time of seismic waves

Use reference table page 11

Seismograph

B. The steps for calculating your distance from the

epicenter:

1. ________________________2. ________________________

3. ________________________

4. ________________________

Subtract arrival time of P from arrival time of S

Mark the interval on Y-axis

Slide marks to match P & S curve

Follow down to x-axisand read distance

01:10:00 01:20:0001:18:00 01:24:00

Step 1 Subtract the arrival time

of the P wave from the

arrival time of the S wave

01:24:00 - 01:18:00 00:06:00Lag time= 6 minutes !!!

Step 2

Mark the interval on the Y-axis

Step 3Slide the marks to

match the P and S Curves.Make sure the

paper is straight!

Step 4Follow down to the X-axis

and read distance

Practice questions:

1. The arrival of the P-wave is 12:03:00.

The arrival of an S-wave is 12:07:00 the difference is:

How far is this earthquake from the seismic station? 4 minutes

2600 Km

Practice questions:2. The arrival time of the

P-wave is 2:05:00The arrival of the S-wave is 2:08:00

the difference is:How far is this earthquake from the seismic station?

3 minutes

1800 Km

Practice questions:

3. If the difference in arrival time between P and S waves is 2 minutes 35 secondswhat is the distance from the earthquake to the

Seismograph stations?1500 Km

Practice questions:

4. How long does it take for a P-wave to travel from the focus of an earthquake to a seismograph station 2,000 km. away?

4 minutes

Practice questions:5. What is the difference in

arrival time between P and S waves for an earthquake

that is 5,000 kilometer away from a seismograph station?

6 mins 40 secs

VII. THE ORIGIN TIME OF AN EARTHQUAKE:

A. Earthquake waves detected at _______ times by observers are at _______ distances from the epicenter.

greater

B. To find the origin time seismologists need to

know:1. _____________________

2. _____________________

Arrival time of P-wave

Travel time of P-wave(how long it took)

Example:

A seismograph recording station located 5,700 km. from an epicenter.

It receives a P-wave at 2:45pmAt what time did the earthquake actually occur at the epicenter?

First:use the distance to find outthe travel time.Then: subtract the travel time from the arrival time.

The answer is:

9 min.

Do Now: Plot the following

City Distance to Epicenter

Denver 1.50 x 103 Km

Tampa 3.80 x 103 Km

San Diego 0.65 x 103 Km

Do Now: Plot the following

City Distance to Epicenter

Wink 1.8 x 103 Km

New York 1.1 x 103 Km

Seattle 3.0 x 103 Km

SF = San Francisco 300 km

LV = Las Vegas 390 km

LA = Los Angeles 189 km

Seismic Stations

TRIANGULATION TO FIND THE EPICENTER

300 km

Do Now:Focused Free Write:

How could you use seismic (P&S) waves to determine if an egg is

raw, soft-boiled or hard-boiled without breaking the egg? Explain in 3-4

sentences.

VIII. THE LAYERS OF THE EARTH:

A. The crusts thickness______ It is _________________ under the oceans and

_________ under continents.

varies

thinner

thicker

Continental crust is mostly_______________, ____________density & __________________

The ocean basins are mostly ________ and ______ or ___________

granitic

dark densebasaltic

lowlight

B. Inferred characteristics of Earth’s

Interior:1. Studying the _____________

of _____________ ________ allows us to make inferences about the structure and composition of the Earth’s interior.

transmission

EarthQuake Waves

S-waves can not pass through liquid

P-waves are bent as they passthrough the different layers

Based on the density of the layer

2. The _____________ of a seismic wave changes with the __________ of the material it travels through.

Waves are also ___________ (bent) as they travel through different densities

velocity

density

refracted

We know that P-waves can be transmitted through

________ _______ & ______

S-Waves can be transmitted through ONLY

________________

solid liquid gas

3. Earth Quake Shadow Zones:When an earthquake occurs both

____________ are received from most of the earth.

Opposite sides of the earth where the epicenter is, receives

____ but NO _______ because S-waves can not penetrate the _______ outer core.

S and P waves

liquid

____________ occurs at the ___________ (boundaries)

refraction interfaces

Let’s Draw This Diagram in our Notebook:

p-wave arrival at 21:58:30

s-wave arrival at 22:02:45

surfacewaves

Summaryp-wave arrival at 21:58:30s-wave arrival at 22:02:45Difference in arrival times — 4

min. 15 sec.Travel Time Curves Distance =

2700 kmActual Distance between

Binghamton, NY and Port-Au-Prince, Haiti = 2647 km

VolcanoesA Volcano is both the opening in the Earth’s crust through which molten rock flows, and the landform that develops around it.

Mt. Etna

Where Volcanoes Form

1. At Subduction Boundaries – Subducted plate material melts to form new magma

Hot magma is less dense than surrounding rock, so it rises.

Magma reaches the surface to form volcanoes

Augustine, Alaska

2. At Divergent BoundariesMagma forms at mid-ocean ridges.

Iceland formed as the result of volcanoes along the Mid-Atlantic Ridge.

3. Hot Spots – Caused by plumes of hot material from deep within the mantle.

Hawaiian Islands were formed in this way.

As plate moves over hot spot, new islands form.

Mauna Loa

Kilauea

Stromboli

Paricutin, Mexico

Nevada Del Ruiz, Colombia

Pacaya, Guatemala

Mount Vesuvius

Pompeii

Crater Lake

Earthquakes final

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