Volcanoes
Volcanoes are very destructive. The volcanoes shoot out lava, hot gas and hot ash. The volcanic gas and ash can be poisonous. They are also formed by plate techtonics. Volcanoes are generally cone-shaped landforms. Volcanoes are like mountains, but the top is cut out. Lava can get up to 60,000 degrees. Volcanoes are in different countries and in Hawaii. Hundreds of volcanoes are active today. It can also errupt in all different kinds of combinations. Under a volcano there is a hot layer called the mantle. The volcano Mt. Saint Helens destroyed 60 people's houses. Volcanoes can erupt with devestating power. And the volcanoes power suddenly goes away and turns to air and ash. The difference between magma and lava: Magma is liquid rock inside the volcano. Lava is liquid rock out of the volcano. There are different types of volcanoes: cinder cone, lava domes, and submarine. Volcano magma goes up to 1,500 degrees.

Historic Vocanoes
When Mt. Vesuvius erupted and destroyed Pompeii with pyroclastic surge. Vesuvius also destroyed Herculanium.

Canyons
Canyons are formed by rivers that run on the land and cut through the land. Some fossils are in the Grand Canyon. There are 170 different types of birds at the Grand Canyon. Some of the oldest rocks lie in the Grand Canyon. The Grand Canyon was cut by the Colorado River. It is 277 miles, 446 kilometers and more than 5000 feet long. Canyons have steep narrow valleys.

Waterfalls
Some waterfall speeds go up to 85 miles per hour. Rainbows produced by mist from an 80ft high waterfall that's visible on a sunny day. A seventeen mile tunnel was dug out to transport water underground because the waterfall had too much water and was overflowing the river.

Dams
A dam is a wall that prevents water flowing freely in rivers and lakes. Dams are usually made to prevent flooding. Some dams aren't built strong enough to hold, so they break. Beavers and humans build dams. Beavers build low ones with sticks. They also use logs and mud. Beavers do not build dams to stop water. They build them to make homes.

Valleys
In December, Death Valley is 65 degrees Farenheit and 85 degrees Celcius. It was created from the weakened earth's crust.
The Hayden Valley in Wyoming was at one time filled with an arm of the Yellowstone Lake. But now, all that is left is the lake's sediments. Hayden Valley is very marshy and has very little trees. Hayden Valley lays beneath a slab of ice nearly 4000 feet thick. That's nearly four times taller than the Eiffel Tower in Paris, France.

DeltaRivers

Delta
A delta is a land made of mud and sand formed into the shape of a triangle helping the water flow into a bigger body of water with help from the mouth of the river.

Mouth of the River
The end of a river flows into another body of water is called the mouth of the river.

Riverbank
The land that is beside the river.

Penninsula
It is a land that is almost fully covered with water. Florida is the best example. It is mostly covered on three sides.

Dunes
They are sand piled over sand. They are caused by wind and are on the coastal plain.

Tundra
It is cold, has no trees, a cold summer and cold winters.

Tributary
It is a little stream that feeds into a river or another big body of water.

Basin
The Great Basin is encompassing the entire state of Nevada and much of Utah, Idaho, and Oregon. The great basin is an arid (dry) mountain land area in the western part of the United States and between the Rocky Mountains.

Isthmus
The Isthmus of Panama is a land bridge that connects North and South America.