Chapter 13 Study Notes Volcanoes. Chapter 13 Section 1 Volcanoes and Plate Tectonics.

Chapter 13 Study Notes

Volcanoes

Chapter 13 Section 1

Volcanoes and Plate Tectonics

1

• ____ is liquid rock produced _____ Earth’s surface.– Magma – under

2

• If the temperature of rock rises ______ the melting point of the minerals the rock is composed of the rock will ____.– above– melt.

3

• Any activity that includes the movement of ______ to Earth’s surface is called ________.– magma – volcanism

4

• ____ is magma that flows onto Earth’s _____.– Lava – surface.

5

• The Pacific ____ __ ____ is both a major earthquake zone and volcano zone. – Ring– of– Fire

6

• A _______ forms on the ocean floor in a _________ zone.– trench – subduction

7

• When oceanic lithosphere _____ beneath oceanic lithosphere, an island ____ forms.– subducts – arc

8

• _____ lava forms on a _________ ridge.– Pillow – mid-ocean

9

• When an ______ volcano erupts, the magma cools quickly, forming _____ lava.– underwater– pillow

10

• ______ is cut by a fissure breaking it into two parts.– Iceland

11

• An area of volcanic activity ____ from a tectonic plate boundary is called a ________.– far – hot spot.

12

• _______ are igneous rock formations created when magma ____ __ reach Earth’s surface, but cools and solidifies ____ the crust.– Pluton – does – not – inside

13

• _____ plutons that can cover an area as large as 100 km2 are called ________.– Large – batholiths.

Chapter 13 Section 2

Volcanic Eruptions

14

• Magma that is rich in ______ and iron is called ___. – magnesium – mafic.

15

• Magma that is rich in _____ and silica is called ______.– feldspar – felsic

16

• _____ eruptions are produced by _____ lava with low viscosity and few trapped gases.– Quiet – runny

17

• When lava cools rapidly, a crust forms on the surface of the flow. If the flow continues, the crust _______ and forms volcanic rock known as ________. – wrinkles – pahoehoe.

18

• The eruption of Mount _________ was an ________ eruption. – St. Helens – explosive

19

• _______ eruptions are produced by ____, sticky lava with high viscosity and a high volume of trapped gases.– Explosive – thick,

20

• Volcanic ___, ____, blocks, _____, and lapilli are all _______ materials. – ash– dust– bombs– pyroclastic.

21

• Pyroclastic material ___ than 0.25 mm in diameter is called volcanic ______.– less – dust

22

• Three type’s volcanoes are _______, _____, and ______ cone. – composite– shield– cinder

23

• A _______ cone is rarely more than a few hundred meters high, with slope angles up to 40°, and formed from ______ eruptions.– cinder – explosive

24

• ________ volcanoes are also known as _________.– Composite – stratovolcanoes

25

• A large circular depression that forms when the magma chamber below a volcano partially empties, causing the ground above it to sink, is called a ______.– caldera.

26

• Volcanic _____ may be signaled by a change in ______ activity. – eruptions – earthquake

The End!!!