* Mantle Plume: Deep within the Earth's mantle, there's a plume of exceptionally hot rock called a "mantle plume." This plume rises because it's less dense than the surrounding mantle material.
* Melting: As the plume rises, the pressure decreases, causing some of the rock to melt. This molten rock, or magma, is less dense than the solid rock around it and starts to ascend.
* Eruption: The magma eventually reaches the surface and erupts, forming volcanoes. The Hawaiian Islands, including Mauna Loa, are formed by such eruptions.
* Shield Volcano: Mauna Loa is a shield volcano . This means that it has gentle slopes and is built up by layers of lava that flowed outward from the vent. The eruptions are typically non-explosive and produce large volumes of fluid lava.
Key Points:
* Hotspot: The location of the mantle plume stays relatively fixed, while the Pacific Plate moves over it. This results in a chain of volcanoes like the Hawaiian Islands.
* Island Chain: As the plate moves over the hotspot, older volcanoes are carried away, leading to a chain of islands.
* Continuous Activity: Mauna Loa is still an active volcano, meaning that it continues to erupt and grow.
In summary, Mount Loa is a shield volcano formed by the eruption of magma from a mantle plume. It's a remarkable example of how volcanic activity can create islands and shape the Earth's surface over time.
