GEOLOGY

Detailed explanation-1: -In the ocean, volcanoes erupt along cracks that are opened in the ocean floor by the spreading of two plates called a mid-ocean ridge . Magma from Earth’s upper mantle rises up to fill these cracks. As the lava cools, it forms new crust on the edges of the cracks.

Detailed explanation-2: -Constructive plate boundary volcanoes Iceland lies on the Mid Atlantic Ridge, a constructive plate boundary, where the North American and Eurasian plates are moving away from each other. As the plates pull apart, molten rock (magma) rises up and erupts as lava, creating new ocean crust.

Detailed explanation-3: -Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes; and. At a convergent plate boundary, one plate dives or “subducts” beneath the other, resulting in a variety of earthquakes and a line of volcanoes on the overriding plate.

Detailed explanation-4: -Based on Figure 2, volcanoes always form near a plate boundary EXCEPT at. subduction zones. major earthquakes. hot spots.