California Science, 4Th Grade, Ch. 5, Lesson 3 Volcanoes

Front 1

volcano

Back 1

-a mountain that builds up around an opening in Earth's crust

Front 2

volcanic eruption

Back 2

-when melted rock, gases, and pieces of rock are formed out of a volcano
-can cause land to change suddenly

Front 3

magma

Back 3

-melted rock
-when trapped gases build up pressure in magma there can be an explosive eruption (like Mount St. Helens, May 1980)

Front 4

vent (in a volcano)

Back 4

-a central opening in a volcano

Front 5

lava

Back 5

-what magma is called once it reaches Earth's surface

Front 6

volcanic mountain

Back 6

-forms when ash and lava build up around the vent

Front 7

Where do volcanoes form?

Back 7

-most occur along fault lines
-also form where Earth's plates move apart
-they form along the edges of spreading plates

Front 8

rift volcanoes

Back 8

-volcanoes that form along the edges of spreading plates
-most rift volcanoes form along the ocean floor

Front 9

hot spots

Back 9

-a place where magma partially melts Earth's crust
-as a plate moves over a hot spot, magma forms, forming a volcano
-an example in the Hawaiian Islands

Front 10

active volcano

Back 10

-the volcano is still erupting
-example is the Island of Hawaii

Front 11

dormant volcano

Back 11

-plate passed over the hot spot a long time ago and the volcano no longer erupts
-example is the Island of Kauai

Front 12

Kinds of volcanoes

Back 12

-Cinder-cones, shields, composites

Front 13

crater

Back 13

-a cup-like shape forming around the vent of a volcano

Front 14

Cinder-Cone Volcano

Back 14

-shaped like a cone
-has steep sides
-consists of rock fragment layers
-thick magma
-a lot of gas is trapped in magma
-because magma is thick, it can become clogged in the volcano
-cuplike shape formed around the vent is the crater

Front 15

Shield Volcano

Back 15

-wide, flat sides
-formed by layers of lava that build up over time and flows gently in all directions
-Mauna Loa, a shield volcano, is world's largest volcano

Front 16

Composite Volcano

Back 16

-made up of layers of lava and ash
-forms during periods of quiet eruptions and explosive eruptions
-over time, layers build up to form a cone shape
-usually symmetrical - the shape on one side of the cone matches the shape on the other side

Front 17

How can you protect yourself during an erupting volcano?

Back 17

-be prepared
-stay away from active volcano sites and flowing lava
-have a pair of goggles and breathing mask available for each member of the family in your safety kit
-if your town has a warning, follow all directions
-if you are inside during an eruption, close all windows and doors. Ensure pets are inside
-if you are caught outdoors, find the nearest shelter and stay inside