繼續和大家介紹地理,今天就和大家介紹各種災難的形成吧
Formation of earthquake (destructive OC CC)
sinking magma movement drive 2 plates to collide, creating great compressional force on the rock of the crust. Denser plate subduct. When great stress accumulates exceed the strength of the rock of the crust, it lead to sudden rock fraction, and vertical rock displacement and reserve fault. Energy release in form of seismic wave, travel to all direction and each the epicentre, it lead to strong vibration of earth surface
formation of tsunami (submarine landslide)
Violent submarine volcanic eruptions leading to part of volcano collapse, the large of volume of rock fall into sea. Then it lead to large volume of seawater being displaced. Tsunami wave travel in all direction and approach the coast, when travelling closer to the coast, tsunami wave length decrease and tsunami wave height increase, it sweep and drown low lying coastal area, tsunami take place
Formation of Hawaii
mantle plume have rising magma, formed hotspot. Magma rise along the cracks, lava extrude, cools and solidifies, forming submarine volcano. After repeated eruption, submarine volcano rise above sea level, becoming a volcanic island. Pacific Plate move NW, the original volcanic island move NW with the plate, becoming far from hotspot, while the hotspot remains stationary. A fresh piece of crust is above the hotspot. After repeated volcanic eruptions, submarine volcano rise above sea level and form a new volcanic island. Volcanic islands continue to move NW with the plate, NW volcanic islands are extinct as they are far away from hotspot, while the SE volcanic island which is on hotspot which remain stationary is still active
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