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The 1883 eruption of ‘Krakatoa’ is geographically famous for causing: (A) A global increase in temperature (B) A massive tsunami that killed thousands (C) The formation of the Himalayas (D) The drying up of the Indian Ocean
The eruption of Krakatoa was a VEI-6 event that fundamentally altered the geography of the Sunda Strait. The explosion was so powerful it was heard 3,000 miles away. However, the most lethal aspect was the massive tsunami triggered by the caldera collapse and pyroclastic flows entering the ocean. ThRead more
The eruption of Krakatoa was a VEI-6 event that fundamentally altered the geography of the Sunda Strait. The explosion was so powerful it was heard 3,000 miles away. However, the most lethal aspect was the massive tsunami triggered by the caldera collapse and pyroclastic flows entering the ocean. The resulting waves obliterated nearly 300 coastal towns and villages. Beyond the immediate physical destruction, the eruption also had global atmospheric effects, injecting enough ash into the sky to create vivid red sunsets worldwide and lowering global temperatures by over 1°C for several following years.
See lessWhich of the following is the highest active volcano in the world?
Standing in the high Andes, Ojos del Salado holds the geographical record for the world's highest active volcano. It is a massive stratovolcano characterized by its dry, high-altitude desert environment. Despite its height, it rarely sees heavy snow due to the arid climate. The volcano is technicallRead more
Standing in the high Andes, Ojos del Salado holds the geographical record for the world’s highest active volcano. It is a massive stratovolcano characterized by its dry, high-altitude desert environment. Despite its height, it rarely sees heavy snow due to the arid climate. The volcano is technically active because it maintains hydrothermal activity and has produced minor ash deposits in recent decades. Its location is a direct result of the intense tectonic compression in the Andean volcanic belt. For geographers, it represents the extreme limit of where active magmatism can occur on Earth’s highest continental crust.
See less‘Basalt’ is a primary rock type associated with: (A) Continental crust (B) Oceanic crust and shield volcanoes (C) Fold mountains (D) Limestone caves
Geographically, basalt is the foundation of the Earth's oceanic basins. It forms at mid-oceanic ridges through the melting of the mantle. Because basaltic lava is very fluid (low viscosity), it can travel long distances, leading to the formation of broad, gently sloping shield volcanoes like those iRead more
Geographically, basalt is the foundation of the Earth’s oceanic basins. It forms at mid-oceanic ridges through the melting of the mantle. Because basaltic lava is very fluid (low viscosity), it can travel long distances, leading to the formation of broad, gently sloping shield volcanoes like those in Hawaii. Basalt is high in iron and magnesium, making it denser than the granitic rocks of the continents. This density difference is why oceanic crust sits lower than continental crust, forming the world’s ocean basins. On land, basaltic flows create fertile plains and massive “flood basalt” provinces.
See lessWhich volcanic feature is used to generate ‘Geothermal Power’ in countries like Iceland and New Zealand?
The geographical advantage of volcanic regions is the accessibility of Earth's internal heat. In countries like Iceland, New Zealand and the Philippines, subterranean steam and hot water are trapped in porous rock layers above magma chambers. By drilling production wells, this thermal energy is brouRead more
The geographical advantage of volcanic regions is the accessibility of Earth’s internal heat. In countries like Iceland, New Zealand and the Philippines, subterranean steam and hot water are trapped in porous rock layers above magma chambers. By drilling production wells, this thermal energy is brought to the surface to drive power plant turbines. After generating electricity, the cooled water is often reinjected into the ground to sustain the reservoir. This “geothermal” geography allows these nations to reduce their reliance on fossil fuels, making volcanism an essential component of their national energy security and environmental sustainability.
See lessThe term ‘Tephra’ refers to: (A) Molten lava (B) All types of airborne volcanic ejecta (ash, rocks) (C) The smell of sulfur (D) Underwater volcanoes
In volcanology, tephra encompasses all fragmental material produced by an explosive eruption. While "lava" refers to molten flow, tephra refers to the solid particles blasted into the atmosphere. Geographers study tephra layers (tephrochronology) to date prehistoric eruptions and understand the freqRead more
In volcanology, tephra encompasses all fragmental material produced by an explosive eruption. While “lava” refers to molten flow, tephra refers to the solid particles blasted into the atmosphere. Geographers study tephra layers (tephrochronology) to date prehistoric eruptions and understand the frequency of volcanic activity in a region. Fine tephra (ash) can travel thousands of miles, impacting aviation and climate, while heavier tephra falls near the vent, building up the volcanic cone. The accumulation of tephra is the primary process by which stratovolcanoes and cinder cones increase their height and geographical footprint.
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