Volcanic activity
Volcano
There is it in the basement of the magma … volcano and is the high temperature material which a rock dissolved in.
It is the place where the magma which rose in the basement of the magma reservoir … volcano collects temporarily.
It gushed out of the crater by the eruption of the volcanic ejecta … volcano. I will learn following five kinds.
- The volcanic gas … chief ingredient is steam
- The volcanic ashes … 2mm in diameter following
- Volcanic bomb … magma got cold in the air and hardened
- It is the 64mm following more than lapilli … 2mm in diameter
- The stone which the trace which pumice … volcanic gas came out of became the small hole, and was left. Very light.
The phenomenon that pyroclastic flow … lava or volcanic gas volcanic ashes fall down the slope of the volcano at high speed
With the form of the volcano; can do it; one
The form of the volcano is decided by stickiness of the magma and is divided into three kinds mainly.
- The volcano where stickiness of the length-formed volcano … magma is weak, and a slope is gentle
- Stickiness of the stratovolcano … magma is a volcano of the middle degree.
- The volcano where stickiness of the dome-formed volcano … magma is strong, and a slope is steep
| Name | Length-formed volcano | Stratovolcano | Dome-formed volcano |
| Figure |  |
 |
 |
| Stickiness of the magma | Weak | Normal | Strong |
| State of the eruption | Calm eruption | Normal | Intense eruption |
| Example of the volcano | KilaueaMauna Loa | SakurajimaMount Fuji
Mount Asama |
Unzen Mt. FugenMount Usu
Showa Shinzan Heisei Niiyama |
| Color of the volcanic ejecta | Black | Gray | White |
| Ratio of silicon dioxide | There is few | Normal | There is many |