volcanoes 1
DESCRIPTION
TRANSCRIPT
Ana lamarca.
Joan rof.
6è de primària.
Eruption
In 1883, in Indonesia, a volcano called Krakatoa erupted at first.
The live of a volcano.
The magma are solid rocks that melt to form hot liquid.
Eventually magma break throug a hole in the Earth’s surface. The hole is called vent.
When magma leaves the vent, it becomes lava.
Plate tectonics theory explains how volcanoes form.
A volcanic eruption.
Types of the volcanoes:
-Active volcano.
-Dormant volcano.
´Extinct volcano.
Volcanic landforms.
Dyferent types of volcanoes:
Fissure volcano.
Shield volcano.
Dome volcano.
Ash-cinder volcano.
Comsostite volcano.
Caldera volcano.
Rocks and lava.
Types of tephra: Bomb,Lapilli,Ash,Dust.
Pahoehoe is when lava flows fast and forms smoth
folds that look like rope.
When show,sticky lava gets hard,it forms rocks with sharp edges it’s called aa.
Sometimes lava forms long, thin strings like human hair. This are called pele’s hair.
Underwater volcano.
The floor of the ocean is similar to dry land. There are flat plains,mountain ridges,canyons, and trenches in the ocean floor.
There are more volcanoes in the ocean than on land.
Living with volcanoes.
The minerals and chemicals in the lava make soil fertile so it is good for farming.
Volcanoes also help to produce electricity.
When the rocks heat underwater, it turns to steam.
People use this steam to make electricity. This is called geotermal energy.
volcanologists.
Special scientists are called volcanologists.They study volcanoes in differents ways.They study rocks and ash from long ago.
