Tectonic hazards gateway 2 (landforms)

Question 1

Apearance/Description of Rift Valleys

idk if this is impt?

Answer 1

• Rift valleys have steep sides
• The continental crust is fractured where rift valley forms
• Rift valley is a linear depression, surrounded by block mountains
• Rift valley is formed between 2 fault lines
• At a rift valley, volcanoes form at the fractures

Question 2

Description of Shield Volcanoes

Answer 2

• Formed at divergent plate boundaries
• Have gentle sloping sides and a broad summit
• Has low-sillica and low viscosity lava
• Lava spreads out over a large area as it allows gases to escape easily
• Only lava erupts during an eruption
• Example: Mount Washington, USA

Question 3

Description of Stratovolcanoes

Answer 3

• Formed at convergent plate boundaries
• Have steep sides at the top, gentler at the bottom, concave, and sometimes has a secondary cone
• Has high-sillica and high viscosity lava
• Lava erupts explosively and does not spread out far from the crater as the lava does not allow gases to escape easily, building up pressure
• Lava, ash, rock fragmnets, gases, volcanic bombs erupt during an eruption
• Example: Mount Mayon, the Philippines & Mount Merapi, Indonesia

Question 4

Formation process of Shield Volcanoes

Answer 4

During an eruption, the lava is less viscous and flows faster and further away from the vent before cooling and solidifying, resulting in the gentler slopes of shield volcanoes

Question 5

Formation process of Stratovolcanoes

Answer 5

• During an eruption, the more viscous lava flows slower and solidifies closer to the vent, resulting in steeper sides and a concave profile
• Because of viscous lava trapping gases, eruptions are more explosive and results in as and pyroclasts as erupted materials, causing the volcano to have layers of solidified lava and pyroclasts forming a cone
• Sometimes, due to a build up of pressure, lava will be forced out through other fractures in the cone, and form a secondary cone after solidifying

Question 6

Impacts of living near volcanic areas (positive and negative)

Answer 6

Positive impacts
- Fertile soil
- Precious stone and minerals
- Tourism 
- Geothermal energy
Negative impacts
- Pollution 
- Massive destruction by volcanic materials

Question 7

Positive impact of Fertile Soil [I]

Answer 7

[D] Fertile soil is formed when lava and ash breakdown in the soil, which can be used for agriculture near volcanoes
[Ex] In Bali, Indonesia, the fertile soil coming from volcanic eruptions help to support the cultivation of crops such as tea, coffee and rice, which largely contribute to the country’s economy. The fertile soil heps to increase the crop yield of the farmers and they can receive more harvest than places far from a volcano
[A] When there is more bountiful harvest, farmers can make more money and improve their standard of living.