Materials released by the volcano (eruption)

1. The solid material (efflata)
According to the original:
a. Efflata allogen; derived from rocks around the crater that was thrown during an eruption
b. Efflata autogen; derived from the work of an explosive volcanic magma erupts.

According to the size of the material
a. Volcanic Bomb, is a big eflata
b. Lapilli, which amounted seed is efflata pecan
c. sand
d. Volcanic ash and dust.

2. liquid materials
a. Lava is magma flow on the surface of the earth
b. Lava lava is a mixture of sand, mud or water.

3. Materials gas (exhalation)
a. Fumaroles or nitrogen (N2)
b. Solfatar or sulfur (H2N)
c. Mofet or carbonic acid gas (CO2).

Signs volcano will erupt (pre-volcanic)
1. temperature or the temperature of the surrounding mountains rise
2. water sources dry up in the surrounding mountains
3. an earthquake
4. animals around the mountain many who move
5. plants around the mountain wither and die.

Signs or symptoms of post (post) volcanic
Is a sign that indicates that in the area were ever volcanic eruptions. The signs include:
1. Exhalation or gas source, usually in the form of:
a. Solfatar (sulfur)
b. Fumaroles (steam hot water)
c. Mofet (carbonic acid gas).

2. Hot springs, for example in the area of ​​Cipanas (West Java).

3. Mineral water sources (makdani), for example in Ciater.

4. Geyser, is the hot springs emanating periodically, eg in Cisolok (West Java).

Influence or benefit volcanism
1. volcanic ash soil fertility
2. volcano is a natural tourist destination attractive
3. can accelerate the process of orographic rain
4. produces industrial minerals such as sand, sulfur, stone, pumice, etc.
5. destruction of volcanic rock that contains nutrients that are beneficial to plants
6. magma intrusion area can contain minerals that humans need such as gold, silver, marble, and others.