 |
| Hotspot |
Hotspots or hot spots are region of active volcanism where mantle feeds the hotspot with magma. The magma rise in the hotspot from mantle to crust. It readily meets the crustal plates and as hotspot comprises of hot magma, it starts to melt the above lying crustal rocks. Some areas can be easily accessed by magma as rocks are not hard enough that can bear the hot magma and doesn't rapidly melt and some rocks can be melted easily. Several minerals have high melting point while some have low. This melting point of minerals suggest the rock either to quickly melt or takes time to break the point. When magma start melting so it rises into the crustal rocks. Some places takes little time to break and magma rises to the surface. This is just the case of the Hawaiian islands where static hotspot point is below the islands.
 |
| Hawaiian islands |
The Hawaiian Islands are at the south eastern end of a chain of volcanoes that began to form more than 70 million years ago. Many of these volcanoes formed islands that have subsided and eroded beneath sea level, and some of the old volcanoes probably never reached sea level. Each Hawaiian island is made of one or more volcanoes, which first erupted on the sea floor and only emerged above the ocean's surface after countless eruptions. As there are series of islands comprises collectively of Hawaiian. All islands are the result from a single static hotspot. The hotspot feeds the surface with lava which starts to build a ridge. The ridge when fed a lot rises above the surface water and form an island. Well how does series of islands have formed with some distance?.
This can be understood by plates drifting. Hawaiian islands are on pacific plate that is most active oceanic plate. As a a ridge reaches the surface and makes an island, due to the Pacific plate movement it drifted away from the hotspot. The hotspot magma rise to the surface again by breaking the plate and starting building again an island which was then drifted away so the series of Hawaiian islands formed.
The Hawaiian islands forming hotspot is still active and as of the Pacific plate movement. This will allow the generation of more islands adding to the Hawaiian series.
ليست هناك تعليقات:
Write التعليقات