Changing Surface
The ____________ is over four and half billion years old.
Earth
_____________ can happen without warning.
Earthquakes
That's when the an earthquake occurs and the land on the surface _______________ and changes.
shifts
___________, like wind and water, can take years to change the surface of the earth.
Natural forces
Molten rock is called ______________. Magma pushes up against the ______________. In some places where Earth's crust is thin or weak, the magma breaks through and pours out. That's when a volcano erupts.
magma, earth's crust
Even though the Earth is about four and half billion years old, ____________, rivers, and ______________ on the Earth's crust aren't that old.
Mountains, Soil
The Earth's crust is made up of many small sections called ___________________.
Tectonic plates
When an earthquake occurs under water, it can set off huge waves called ________________.
tsunamis
Erosion and weathering are natural events that _____________ and carry away rocks.
break down
Gas and magma are ejected from the volcanoe. When magma pours out of the Earth's surface it's called ________________.
lava
That's because the surface of the Earth is ___________________ changing.
Constantly
Sometimes the __________ between these two plates appear as cracks on the Earth's surface. These cracks are called ________________.
boundaries, faults
Tsunamis can be 15 to 200 meters tall when they hit the _____________.When a wave that tremendous hits the shore, it can wipe away land, ____________ and even cities.
forests, suddenly
Over time, a large boulder, can break down into ___________ pieces. This process is called ________________.
smaller, weathering
Lava can scorch and _____________ entire forests, cities, and even civilizations. Overflowing lava builds up new land and soil that is _____________ in minerals. These minerals are useful to _____________ and animals
destroy, rich, plants
________________ are an important natural force that can change the Earth's surface. It is a river of ice that moves down slowly with a little help from ____________.
glacier, gravity
The famous ___________________ in California is a perfect example.
San Andreas fault
Earthquakes can also cause ______________. A landslide occurs when rocks and rubble __________ slide off a slope really fast.
landslide, shape
In weathering, the rocks break down in the same ________ they are found. Trees and plants grow their ____________ split the rock into smaller pieces.
place, roots
There are volcanoes on land and ___________. When volcanoes erupt under water, the lava cools under water ad forms a ______________.
underwater, crust
When you see a flat, ________________ landscape with lots of lakes, it usually means that the area was once ______________ in glaciers.
rocky, covered
Most of the time, these tectonic plates just ______________ one another. But sometimes they __________ or move into each other.
slide by, collide
During an ________________ tons of snow falls down a slope.
avalanche
Pieces of rock move from one place to another through a process called ________________.
Erosion
As more and more lava cools, the crust builds up above the surface of the water and forms an ____________. The _____________ islands were formed in this way.
island, Hawaiian