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!!!