Download Get Up and Go

Title: Volcanoes (BLR)
Author: Emiliano Bermejo Black
Mount St. Helens
It was the morning of May 18, 1980. A powerful earthquake shook the
mountains in the state of Washington. Seconds later, the top of Mount St.
Helens exploded and slid away in a huge landslide.
Powerful explosions ripped through the sliding rocks. Hot ash, gas, and
whirling stream burst up and out of the mountain. The volcano was
erupting.
The blast shot out of the side of the mountaintop. It snapped huge trees
like matchsticks. Everything in its path was destroyed.
A huge cloud of ash and gas rapidly formed above the mountain. It
blotted out the sun, turning morning into night. The cloud blew east across
the United States. Within three days, ash from the volcano traveled all the
way across the country from its source.
Why Do Volcanoes Erupt?
Long ago, ancient people told stories to explain why volcanoes erupted.
But they didn’t know what really caused them. Scientists now know a lot
more about our planet.
Earth is made up of three layers. The top layer is called the crust. The
crust is the layer we walk on. It is made up of rock.
Below the crust is the mantle. This layer is very hot. It is so hot that
some of the rock there actually melts. The melted rock is called magma.
Deep inside the Earth is the core. It is made up of different metals.
Earth’s crust is not all in one piece. It is actually made up of huge rock
plates. These plates cover Earth like the pieces of a giant jigsaw puzzle.
We can’t feel it, but these plates are always moving. In some places, the
plates pull apart. In other places, the plates push together.
When two plates pull apart, they can create an opening. Volcanoes
happen when gases, hot ash, and melted rock push up from the mantle
through these openings. The hot melted rock is called lava (LAH vuh) when
it ours out of a volcano.
The Dangers of Volcanoes
Volcanoes are very destructive. Lava can be hotter than 1,000 degrees!
It will instantly kill and destroy anything in its path.
3
16
29
38
49
61
62
75
84
97
110
123
130
134
145
158
162
177
190
207
219
233
249
262
276
286
297
310
324
329
333
345
354
4 Grade, Unit 3, Lesson 11
Title: Volcanoes (BLR)
Author: Emiliano Bermejo Black
Mount St. Helens
It was the morning of May 18, 1980. A powerful earthquake shook the
mountains in the state of Washington. Seconds later, the top of Mount St.
Helens exploded and slid away in a huge landslide.
Powerful explosions ripped through the sliding rocks. Hot ash, gas, and
whirling stream burst up and out of the mountain. The volcano was
erupting.
The blast shot out of the side of the mountaintop. It snapped huge trees
like matchsticks. Everything in its path was destroyed.
A huge cloud of ash and gas rapidly formed above the mountain. It
blotted out the sun, turning morning into night. The cloud blew east across
the United States. Within three days, ash from the volcano traveled all the
way across the country from its source.
Why Do Volcanoes Erupt?
Long ago, ancient people told stories to explain why volcanoes erupted.
But they didn’t know what really caused them. Scientists now know a lot
more about our planet.
Earth is made up of three layers. The top layer is called the crust. The
crust is the layer we walk on. It is made up of rock.
Below the crust is the mantle. This layer is very hot. It is so hot that
some of the rock there actually melts. The melted rock is called magma.
Deep inside the Earth is the core. It is made up of different metals.
Earth’s crust is not all in one piece. It is actually made up of huge rock
plates. These plates cover Earth like the pieces of a giant jigsaw puzzle.
We can’t feel it, but these plates are always moving. In some places, the
plates pull apart. In other places, the plates push together.
When two plates pull apart, they can create an opening. Volcanoes
happen when gases, hot ash, and melted rock push up from the mantle
through these openings. The hot melted rock is called lava (LAH vuh) when
it ours out of a volcano.
The Dangers of Volcanoes
Volcanoes are very destructive. Lava can be hotter than 1,000 degrees!
It will instantly kill and destroy anything in its path.
4 Grade, Unit 3, Lesson 11
Title: The Big, Dangerous Wave (ELLR)
Author: Gary Miller
It was early in the morning on December 26, 2004. The Indian Ocean
was very calm. But at the bottom of the sea, a big piece of the sea floor
suddenly moved. The movement caused a big earthquake. The earthquake
registered, or was measured, at 9.0 on the Richter scale. The Richter scale
is the measurement scientists use to tell others how strong an earthquake
is.
As the sea floor moved, it also moved the water above it. This
movement caused a huge wave, which moved away in all directions. This
big, dangerous wave was called a tsunami (Soo NAM ee). When the wave
finally reached land, it caused a lot of damage.
A Big, Dangerous Wave
What is a tsunami? It is not an ordinary wave. Wind and tides are the
source, or cause, of most ocean waves. When wind blows along the top of
the ocean, it causes waves. The tides cause the ocean waves to move,
pulling water toward the shore, and then pulling it away. This causes
waves, too.
A tsunami is different. It is a big, dangerous wave caused by a strong
movement of land into or below the sea. Landslides can cause tsunamis.
Volcanoes can cause tsunamis, too. But most tsunamis care caused by
earthquakes.
It Starts with an Earthquake
The outside of the Earth is made up of big pieces of rock called tectonic
plates. These plates are like big puzzle pieces, except they move.
Sometimes two plates try to move past each other. When they do, the
plates slip quickly.
When this slipping happens, the ground above the plates moves.
Sometimes the group moves so little people can barely feel it. Sometimes it
moves a lot, causing the ground under people’s feet to shake a lot. This is
called an earthquake.
When an earthquake happens beneath the ocean, the land on the sea
floor moves. The water above the sea floor moves, too.
How a Tsunami Happens
To understand how a tsunami is made, look carefully at the picture. As
one part of the sea floor moves up, the water above it moves up, too. At the
same time, another part of the sea floor drops. The water above it drops,
too.
13
30
40
53
65
66
79
91
104
113
117
133
146
159
171
173
187
199
210
211
216
231
242
255
258
268
281
296
299
311
321
325
338
355
370
371
4 Grade, Unit 3, Lesson 11
Title: The Big, Dangerous Wave (ELLR)
Author: Gary Miller
It was early in the morning on December 26, 2004. The Indian Ocean was
very calm. But at the bottom of the sea, a big piece of the sea floor
suddenly moved. The movement caused a big earthquake. The earthquake
registered, or was measured, at 9.0 on the Richter scale. The Richter scale
is the measurement scientists use to tell others how strong an earthquake
is.
As the sea floor moved, it also moved the water above it. This
movement caused a huge wave, which moved away in all directions. This
big, dangerous wave was called a tsunami (Soo NAM ee). When the wave
finally reached land, it caused a lot of damage.
A Big, Dangerous Wave
What is a tsunami? It is not an ordinary wave. Wind and tides are the
source, or cause, of most ocean waves. When wind blows along the top of
the ocean, it causes waves. The tides cause the ocean waves to move,
pulling water toward the shore, and then pulling it away. This causes
waves, too.
A tsunami is different. It is a big, dangerous wave caused by a strong
movement of land into or below the sea. Landslides can cause tsunamis.
Volcanoes can cause tsunamis, too. But most tsunamis care caused by
earthquakes.
It Starts with an Earthquake
The outside of the Earth is made up of big pieces of rock called tectonic
plates. These plates are like big puzzle pieces, except they move.
Sometimes two plates try to move past each other. When they do, the
plates slip quickly.
When this slipping happens, the ground above the plates moves.
Sometimes the group moves so little people can barely feel it. Sometimes it
moves a lot, causing the ground under people’s feet to shake a lot. This is
called an earthquake.
When an earthquake happens beneath the ocean, the land on the sea
floor moves. The water above the sea floor moves, too.
How a Tsunami Happens
To understand how a tsunami is made, look carefully at the picture. As
one part of the sea floor moves up, the water above it moves up, too. At the
same time, another part of the sea floor drops. The water above it drops,
too.
13
30
40
53
65
66
79
91
104
113
117
133
146
159
171
173
187
199
210
211
216
231
242
255
258
268
281
296
299
311
321
325
338
355
370
371
4 Grade, Unit 3, Lesson 11