26s Novice English
[No audio. Translated by Teachers Without Borders]
扩张洋中脊形成了世界上最长的山脊。地幔中形成的玄武岩岩浆上涌侵入地壳中的断裂，凝固后便在该边界处形成了新的洋壳。因为位于洋脊顶部的年轻大洋板块很热，其密度低于位于洋脊两侧的更老，更冷，密度更高的板块，便导致了扩张洋中脊的海拔很高。随着板块从该边界向两侧移动，因其下覆的地幔岩石逐渐冷却并凝固在板块的底部，板块逐渐增厚。
The subduction zone iswhere two tectonic (lithospheric) plates come together, one subducting (diving) beneath the other. The plates are locked together and periodically overcome the friction causing the leading edge of the overlying plate to surge back, lifting a wall of water producting a tsunami.
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