plate tectonic gw2

Question 1

explain how fold mountains are formed

Answer 1

Fold mountains are formed at convergent plate boundaries, where plates move towards each other and collide. An example of fold mountain is the Himalayas mountain that formed due to collisaion of Indian and Eurasian plate creating a compressional force. Due to immense pressure on the plates, layers of rock buckle and fold.

Question 2

types of lava

Answer 2

low-silica lava
high-silica lava

Question 3

characteristics of lava

Answer 3

low-silica lava: 1. low viscosity 2. flows quickly over long distance 3. non-explosive volcanic eruption
high-silica lava
1. high viscosity 2. flows slowly over short distance 3. explosive volcanic eruption

Question 4

types of volcano

Answer 4

shield volcano: along divergent plate boundary, low-silica lava, gentle sloping slides, less explosive eruption

stratovolcano: along convergent plate boundaries, high-silica lava, more explosive eruption

Question 5

risks of living near volcanic areas

Answer 5

destruction by volcanic materials
Lava, rock fragments and volcanic bombs can lead to widespread damage to property and cause loss of lives. Low silica lava moves rapidly and flows over a long distance causing damage to wider area. Inhaling hot ash and gases can lead to respiratory problems. For example, the lava flow during the eruption in Kilauea, Hawaii since 1983 has left many homes and highways destroyed.

Question 6

benefits of living near a volcanic area

Answer 6

tourism
volcanic areas allow tourists to hike, camp and enjoy scenery. Tourists can learn about the history of the volcanic area. For example, Pompeli, Italy. The town was buried by layers of ash from Mount Vesuvius when it erupted during 79CE. Almost 3 million people visit the area every year

fertile volcanic soil
Lava and ash can break down to form volcanic soil. Volcanic soil are fertile and beneficial for farming. For example, Java and Bali in Indonesia support the cultivation of crops such as tea, coffee and rice. That is why they are able to support a large rural population over the years

Question 7

risk associated with living in earthquake zone

Answer 7

Tsunami is an unusually large wave that is formed by the movement of sea floor during a large earthquake at the subduction zone. Tsunami is formed as seismic energy from offshore earthquake forces out a mass of sea water. The tsunami waves may start at a height of less than 1m, with wave length of 100-150km at speeds of 80km/h. On reaching swallower water, greater friction slows waves and forces them to increase in height. Sometimes, the sea recedes from the coast before advancing onshore. For example, In 2004, a 9.2 magnitude earthquake occured in Indian Ocean near Banda Aceh in Indonesia resulting in a tsunami which travelled over a long distance, causing damage to coastal communities in 12 countries.