TodayToday

Hand in LAB EQ Location & OLD WORKHand in LAB EQ Location & OLD WORK Check the list in the back, if you owe Check the list in the back, if you owe

something.something. Get out a small piece of paper, PUT YOUR Get out a small piece of paper, PUT YOUR

NAME ON IT.NAME ON IT.

Review –EQ LOCATIONReview –EQ LOCATION

P-wave & S-wave arrival times Subtract (S-P time) Look up Distance in Km (ESRT)

– HOW? P-wave travel time (ESRT)

– HOW? Origin Time (P-wave arrival – P-wave

travel)

QuizQuiz

Get out your ESRTGet out your ESRT You have 15 minutes to hand in this quiz. You have 15 minutes to hand in this quiz.

NO more. Good luckNO more. Good luck

Plates and VolcanoesPlates and Volcanoes

Where do we find volcanoes?Where do we find volcanoes?

Divergent plates ???Divergent plates ???– YES!YES!

Transform Plates ???Transform Plates ???– NO! Not usuallyNO! Not usually

CONVERTGENT Plates??CONVERTGENT Plates??– YES!YES!

Convergent PlatesConvergent Plates

Where two plates come togetherWhere two plates come together

Types of MagmaTypes of Magma

The type of magma that is made from the The type of magma that is made from the volcano is based on the mineral content.volcano is based on the mineral content.

More Aluminum and quartz = More Aluminum and quartz = FelsicFelsic

More Iron, Magnesium = More Iron, Magnesium = MaficMafic

Felsic MagmaFelsic Magma

Lots of Lots of QuartzQuartz Sticky (high Sticky (high viscosityviscosity)) Can hold Can hold lots of pressurelots of pressure

Rocks from a felsic magma usually form Rocks from a felsic magma usually form Granite (density of 2.7g/cmGranite (density of 2.7g/cm33))

Mafic MagmaMafic Magma

Very Very little Quartzlittle Quartz Not very stickyNot very sticky Doesn’t hold pressureDoesn’t hold pressure

Mafic magma makes Basalt (density of 3.0 Mafic magma makes Basalt (density of 3.0 g/cmg/cm33))

Types of lavaTypes of lava

A’ AA’ A’’– Chunky Chunky

Pahoe’ pahoe’Pahoe’ pahoe’– RopyRopy

How does magma effect Volcanoes?How does magma effect Volcanoes?

If the If the magma holds the pressure it will blow magma holds the pressure it will blow up more violentlyup more violently

If there is less pressure more of a fluid If there is less pressure more of a fluid eruption.eruption.

This allows different volcanoes to form.This allows different volcanoes to form.

Cinder Cone VolcanoCinder Cone Volcano

When the eruption occurs rocks thrown from When the eruption occurs rocks thrown from the volcano and land next to opening.the volcano and land next to opening.

Small, but steep sidesSmall, but steep sides

Felsic magmaFelsic magma

Composite VolcanoComposite Volcano Layers of magma/lava flow on top of one Layers of magma/lava flow on top of one

another to form volcanoes sides.another to form volcanoes sides.

Large and steep sidesLarge and steep sides

Felsic magma – Felsic magma – VERY EXPOSIVE!VERY EXPOSIVE!

– Mt. Vesuvius in ItalyMt. Vesuvius in Italy

Shield VolcanoShield Volcano

Large flattened volcanoes formed lava Large flattened volcanoes formed lava layering on top of otherslayering on top of others

Mafic MagmaMafic Magma

Not Explosive! Not Explosive!

Parts of a volcanoParts of a volcano

IntrusionsIntrusions When magma makes its way into other When magma makes its way into other

layers on the earth. layers on the earth. Usually Sedimentary layers have igneous Usually Sedimentary layers have igneous

intrusions. intrusions.

Hot SpotsHot Spots

Hot Spots Hot Spots

These are spots where the magma below is These are spots where the magma below is rising to the surface and the plates move over rising to the surface and the plates move over them.them.

NEXTNEXT

LAB 15 Page 60-64 1.) READ!!!! 2.) Fill in chart, use data on page 63. 3.) Plot data on page 63 in graph on page

64. 4.) Follow steps on page 61. 5.) Answer questions.

TodayToday

Hand in any work needed.Hand in any work needed. Check the list in the back, if you owe Check the list in the back, if you owe

something.something. Get out a small piece of paper, PUT YOUR Get out a small piece of paper, PUT YOUR

NAME ON IT.NAME ON IT. When bell rings the quiz will start and you When bell rings the quiz will start and you

will have 1 minute per question to answer.will have 1 minute per question to answer.

Question 1Question 1

Name the three plate boundaries.Name the three plate boundaries.

Question 2Question 2

If the P-wave arrived at 12:03:00 and the S-If the P-wave arrived at 12:03:00 and the S-wave arrived at 12:07:40, how far away is wave arrived at 12:07:40, how far away is the EQ epicenter?the EQ epicenter?

Question 3Question 3

What drive plate movement?What drive plate movement?

AnswersAnswers

Convergent, Divergent, TransformConvergent, Divergent, Transform 3200km3200km Convection Convection