Answer:
Explosive and effusive eruption types resulting from the activity of magma composition, temperature, water content and volatile content.
Explanation:
Magma Silica content composition being above 60% will result in violent eruption. High temperature will result in low viscosity and low temperature in high viscosity. Explosive eruptions are propelled by magma and motivated by gaseous activity. Effusive is characterized with lava outflow without explosive activity. Examples of this effusive eruptions are those of the Hawaiian eruptions. Plinian eruptions are known to be explosive, violent and dangerous.
With a country as big as Russia, it is hard to give you an accurate estimation. Siberia is known for some of the coldest winters in the world, reaching a very dangerous -35 degrees Celsius. The north pole of cold has a record breaking -69 degree celsius winters. over 65% of Russia is covered by permafrost. There is a humid continental climate as well.
'Climatic variations' and 'Human activities' can be regarded as the two main causes of desertification. removal of the natural vegetation cover（by taking too much fuel wood）, agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity.
The Rift Valley was formed by violent subterranean forces that tore apart the earth's crust.
