tectonics kq2 - volcanoes Flashcards
characteristics of stratovolcano lava
- high silica lava (from melting of subducted crust in mantle)
- more viscous (hard to flow)
- lower temp
characteristics of shield volcano’s lava
- low silica lava (from mantle of earth)
- less viscous lava (easier to flow)
- higher temp
features of stratovolcano
- smaller base: lava has high viscosity and lower temperature = travel a shorter distance before solidifying
- taller: more lava accumulates at base before cooling and solidifying
- steep slope
features of shield volcano
- bigger base: lava has low viscosity and higher temp = travel a further distance before solidifying
- shorter: less lava accumulates at base before cooling and solidifying
- gentler slop
how is eruption of stratovolcano (due to its high silica lava)
more likely for the magma to solidify inside the volcano = will block the vent and trap magma
harder for gases in the magma to escape = more pressure builds up
More explosive eruption
how is eruption of shield volcano (due to its low lava)
less likely for the magma to solidify inside the volcano = will not block the vent and trap magma
easier for gases in the magma to escape = less pressure builds up
less explosive eruption.
why is geothermal energy from volcanoes a benefit
- Using geothermal energy reduces need to burn fossil fuels to meer energy needs = less carbon emission = reduce climate change + cleaner air
- Cheaper energy cost = govt can use saved money into improving lives of citizens = higher SOL
hazards of shield volcano
Lava is fast-flowing and lava is of high temp = may destroy and burn things is its path
why is fertile volcanic soil a benefit
DESC: Lava and ash break down to form fertile soil after thousands of years
EXP: Fertile soil allows more crops to be grown = farmers living in volcanic area get to enjoy harvesting more crops than farmers in non-volcanic areas = excess crops are sold = earn more income = higher SOL
More crops are grown = sufficient food supply = higher SOL
why are volcanoes as a tourist attraction beneficial
DESC: volcanoes provide scenic views, attractions like hotsprings
EXP: Economic impact: job opportunities created with influx of tourists = earn more income = higher SOL
hazards of stratovolcano
- More explosive eruption = produces more volcanic ash and volcanic bombs
- Produces pyroclastic blast: fast moving current of hot gases and burning rocks = burn and destroy things in its path
- Lahar: fast-flowing mudflow formed from erupted volcanic ash mixing with rain = floods and bury areas near a volcano
- Ash clouds: ash from eruptions sent into atmosphere and circulate around world
why are precious stones and diamonds from volcanoes beneficial
Provides job opportunities to locals: mine the stones and minerals = sell them = earn income = higher SOL
how can volcanoes lead to the risk of destruction by volcanic materials
- The fast-flowing lava and pyroclastic flow will burn all properties in its way =
- People at the area may not escape in time = people suffer from burns and even death.
- Volcanic bombs and the rocks in the pyroclastic flow will crush and kill anything in its path.
- The lahar would bury anything in its way, destroying properties and drowning people who cannot escape in time.
–> Victims can suffer from the trauma of losing their loved ones and homes
how can volcanoes lead to the risk of air pollution
DESC: Volcanic eruptions release ash, gases such as carbon dioxide/sulfur dioxide/carbon monoxide = spread across a large area
EXP:
1. The ash may land on crops or block
the sunlight = crops may die =
insufficient food to be produced = starvation
2. When people in the affected areas breathe in the ash particles, it can lead to breathing problems and lung diseases.
3. Volcanic eruptions affect number of flights that can happen = tourists discouraged from visiting = less business opportunities for people working in tourism related jobs = income losses
