Examine the efficiency of early warning systems for responding to and preparing for cyclones.
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.
See less
Early warning systems alert communities of impending cyclones through timely and reliable forecasts , enabling evacuations and preparations to minimize damage.India's early warning systems for cyclones include IMD's Doppler Radar, Satellite Imagery, and Mobile Alerts. Examples - Cyclone Phailin (201Read more
Early warning systems alert communities of impending cyclones through timely and reliable forecasts , enabling evacuations and preparations to minimize damage.India’s early warning systems for cyclones include IMD’s Doppler Radar, Satellite Imagery, and Mobile Alerts. Examples – Cyclone Phailin (2013) and Fani (2019) saw timely evacuations, minimizing casualties. India’s National Disaster Management Authority’s (NDMA) mobile app and SMS alerts also enhance preparedness.
Effectiveness of Early Warning System –
Limitations of Early Warning Systems (EWS) in cyclone prone areas include forecasting errors, communication gaps and infrastructure constraints. Technological advancements address these by improved satellite imaging, AI enhanced forecasting, mobile apps, IoT sensors and drone based monitoring enhance accuracy, speed and reach, optimizing cyclone preparedness and response.
See less