chapter 13 study notes
DESCRIPTION
Chapter 13 Study Notes. Volcanoes. 1. A _______ cone is rarely more than a few hundred meters high, with slope angles up to 40°, and formed from ______ eruptions. cinder explosive. 2. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 13 Study Notes
Volcanoes
1
• A _______ cone is rarely more than a few hundred meters high, with slope angles up to 40°, and formed from ______ eruptions.– cinder – explosive
2
• 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.
3
• A _______ forms on the ocean floor in a _________ zone.– trench – subduction
4
• An area of volcanic activity ____ from a tectonic plate boundary is called a ________.– far – hot spot.
5
• Any activity that includes the movement of ______ to Earth’s surface is called ________.– magma – volcanism
6
• ________ volcanoes are also known as _________.– Composite – stratovolcanoes
7
• _______ eruptions are produced by ____, sticky lava with high viscosity and a high volume of trapped gases.– Explosive – thick,
8
• ______ is cut by a fissure breaking it into two parts.– Iceland
9
• If the temperature of rock rises ______ the melting point of the minerals the rock is composed of the rock will ____.– above– melt.
10
• _____ plutons that can cover an area as large as 100 km2 are called ________.– Large – batholiths.
11
• ____ is magma that flows onto Earth’s _____.– Lava – surface.
12
• ____ is liquid rock produced _____ Earth’s surface.– Magma – under
13
• Magma that is rich in _____ and silica is called ______.– feldspar – felsic
14
• Magma that is rich in ______ and iron is called ___. – magnesium – mafic.
15
• _____ lava forms on a _________ ridge.– Pillow – mid-ocean
16
• _______ are igneous rock formations created when magma ____ __ reach Earth’s surface, but cools and solidifies ____ the crust.– Pluton – does – not – inside
17
• Pyroclastic material ___ than 0.25 mm in diameter is called volcanic ______.– less – dust
18
• _____ eruptions are produced by _____ lava with low viscosity and few trapped gases.– Quiet – runny
19
• The eruption of Mount _________ was an ________ eruption. – St. Helens – explosive
20
• The Pacific ____ __ ____ is both a major earthquake zone and volcano zone. – Ring– of– Fire
21
• Three type’s volcanoes are _______, _____, and ______ cone. – composite– shield– cinder
22
• Volcanic ___, ____, blocks, _____, and lapilli are all _______ materials. – ash– dust– bombs– pyroclastic.
23
• Volcanic _____ may be signaled by a change in ______ activity. – eruptions – earthquake
24
• When an ______ volcano erupts, the magma cools quickly, forming _____ lava.– underwater– pillow
25
• 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.
26
• When oceanic lithosphere _____ beneath oceanic lithosphere, an island ____ forms.– subducts – arc
The End!!!