Daily Review #4Describe the 4 different pieces of

evidence to support continental drift

How does convection cause a plate to move?

Discuss your answer to the writing prompt about what you think will happen to the continents in 100 million years.

Plate TectonicsMovement

◦cm/yr◦Measured

by GPSInteract at

boundaries – 3 types◦Collide◦Separate◦Slide past

Earthquakes can occur at all

ConvergentBoundary

Plates collideContinental-

continental◦ Create mountains

Continental-oceanic◦ Oceanic sinks◦ Subduction zone

and trench◦ Remelted, recycled

Oceanic-oceanic◦ One subducts

Transform BoundaryPlates slide past eachNot usually smoothLarger, more

frequent earthquakes

Earthquakes

What are they? What is it like?

SeismologistWhere?

◦ Plate boundary◦ Rarely in middle

of continent◦ Occur at or

create faults◦ Varying depths◦ Focus

Epicenter

How are earthquakes measured?

Richter scale◦ Strength

(magnitude)◦ Measuring ground

motion◦ Used by the media

Moment magnitude◦ More precise◦ Measures the

energy released◦ Measured at the

epicenter◦ Used by scientists

Largest Recorded Earthquakes

Recent earthquakes

Imaging of Earthquake Waves

Seismograph◦Shows local

movement

◦3 main waves1. P wave2. S wave3. Surface

waves

Finding the EpicenterDistance vs. time

graph is constant◦ Closest has

smallest time difference

Measure time difference on local seismograph◦ Compare to graph◦ Find distance

Repeat for multiple locations

Finding Epicenter cont.

Use distances found

Draw a circle from each site

Overlap = epicenter

Daily Review #5How are convergent and

transform boundaries similar? Different?

Give a current example of a convergent boundary and what is being formed there

What is an epicenter and how is it found?

What kind of damage can an earthquake cause and how do you think we could prevent that damage?

Elastic Rebound Hypothesis

Energy buildsEnergy

released◦Travel as

wavesRocks return

to original shape, but different locations

Earthquake Waves

P waves◦ First detected◦ Back-and-forth

S waves◦ Side-to-side◦ Slower, arrive later

Surface◦Rolling◦Side-to-side

◦Slowest◦More destructive

Aftershocks

Foreshocks

Earthquake Hazard Map

Earthquake PredictionNot exactSeismic gaps

◦Area of fewer earthquakes

◦Likely location of future earthquake

◦Used to predict 1989 San Francisco

Past frequency

Destruction from Earthquakes

Liquefaction◦ Mixing soil with

underground water◦ Sinkholes

LandslidesFire

◦ Broken gas and electrical lines

◦ Lack water to fight

Building and highway damage

TsunamiCause

◦Underwater earthquake

◦Ocean floor movement

Massive waves

Closer to shore◦Slows◦Increases in height

Tsunami warning system

Only a few a year

Most recent (major)◦Indonesia (Dec.

2004)◦Japan (Mar.

2011)Seiche