Roadmap for Answer Writing 1. Introduction Brief Definition of Magma: Explain that magma is molten rock beneath the Earth’s surface, containing gases like carbon dioxide, sulfur, nitrogen, and chlorine. Purpose of Answer: The answer will explore how different types of magma (basic and ...
Cyclones devastate communities by causing loss of life, infrastructure damage, economic disruption, environmental degradation and displacement with long term effects on ecosystems, biodiversity and psychological well being of affected populations. Impacts of Cyclones on ecosystems and biodiversity -Read more
Cyclones devastate communities by causing loss of life, infrastructure damage, economic disruption, environmental degradation and displacement with long term effects on ecosystems, biodiversity and psychological well being of affected populations.
Impacts of Cyclones on ecosystems and biodiversity –
- Cyclones alter species composition by disrupting food chains, favoring invasive species and reducing native populations, leading to changes in ecosystem structure, function and biodiversity, potentially extirpating vulnerable species locally.
- Cyclones trigger biodiversity loss through habitat destruction, population decline and local extinctions, eroding genetic diversity, disrupting species interactions and altering ecosystem processes, compromising ecosystem resilience and ecological integrity.
- Cyclones cause ecosystem degradation through habitat destruction, soil erosion, water pollution and disruption of nutrient cycles, weakening ecosystem resilience, altering ecosystem services and reducing ecological function and biodiversity.
- Cyclones increase ecosystem vulnerability by weakening natural barriers, altering coastal geomorphology and disrupting ecosystem processes, making communities more susceptible to future storms, flooding and climate change impacts.
- Cyclones displace species, altering habitats and populations, forcing migrations and disrupting delicate ecosystem balances suddenly.
Cyclone recovery efforts offer opportunities for ecological renewal through habitat restoration, reforestation, species reintroduction, and ecosystem-based adaptation, enhancing resilience, promoting biodiversity, and supporting sustainable ecosystem services and community livelihoods.
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Model Answer Volcanoes are shaped and their explosive nature is determined largely by the type of magma involved in their formation. The composition of magma, including its viscosity and gas content, plays a crucial role in both the volcano's shape and how violently it erupts. 1. Basic Lava and ShieRead more
Model Answer
Volcanoes are shaped and their explosive nature is determined largely by the type of magma involved in their formation. The composition of magma, including its viscosity and gas content, plays a crucial role in both the volcano’s shape and how violently it erupts.
1. Basic Lava and Shield Volcanoes
Basic lava, which is rich in iron and magnesium but low in silica, is highly fluid and flows easily. This type of lava is typically dark in color, such as basalt, and has a lower viscosity, allowing it to travel long distances before solidifying. Due to its fluid nature, it leads to the formation of shield volcanoes, which have broad, gently sloping sides. These volcanoes are less explosive because the lava can flow easily, allowing gas to escape gradually. An example of a shield volcano is the Big Island of Hawaii, which has been formed by the consistent outpouring of basic lava.
2. Acid Lava and Composite Volcanoes
Acid lava, in contrast, is rich in silica, making it more viscous and harder for gas to escape. This leads to a build-up of pressure, which results in explosive eruptions. Acid lava tends to solidify quickly and does not travel far, leading to the formation of steeper, conical-shaped volcanoes known as composite volcanoes. These volcanoes are typically characterized by alternating layers of solidified lava and pyroclastic material. Examples include Mount Fuji in Japan, Mount Rainier in the U.S., and Mayon Volcano in the Philippines. The high viscosity of the magma often causes eruptions to be violent, with eruptions creating loud explosions and even forming calderas—large depressions that can result when a volcano collapses after an explosive eruption. Notable calderas include the Yellowstone Caldera in Wyoming and Long Valley Caldera in California.
3. Viscosity and Explosiveness
In general, the higher the viscosity of the magma, the more explosive the eruption. This is because thicker magma traps gases, increasing pressure until it is released explosively. Therefore, while basic lava leads to non-explosive eruptions, acid lava results in some of the most explosive volcanic activity on Earth.
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