Shield Volcano Flashcards
Give an example of a shield volcano.
The Mauna Loa volcano is one of five volcanoes that form the Hawaiian hotspot landscape.
Where are shield volcanoes found and what kind of shape are they?
Wide shallowly sloping
Relatively fluid basaltic lava
Shield volcanoes are usually found at constructive or tensional boundaries and they are wide volcanoes with shallowly sloping sides that are formed by lava flows of low viscosity lava that flows easily. Consequently, a volcanic mountain having a broad profile is built up over time by flow after flow of relatively fluid basaltic lava issuing from vents or fissures on the surface of the volcano.
Some characteristics of Mauna Loa?
56,000 feet. (USGS)
75 miles wide and encompasses a land area of 2,035 square miles.
From its true base to its summit, it is about 56,000 feet. (USGS)
It is so tall it is sometimes snow capped despite being in Hawaii.
This volcano is an excellent example of how long term effusive eruptions produce very distinctive and large scale features.
The sides of Mauna Loa are very shallow, but its dome is 75 miles wide and encompasses a land area of 2,035 square miles.
Its height above sea level is 13,677 feet, and it descends 16,400 feet more to the ocean floor where it depresses the Earth’s crust for a further 5 miles.
Lava eruptions, from a plume of magma known as the Hawaiian hot spot, began the formation of Hawaii’s Mauna Loa 600,000 to 1 million years ago.
This plume of magma is responsible for the formation of the entire chain of Hawaiian islands.
In comparison (first sentence)
In comparison, shield volcanoes are very much different to composite volcanos. Lava flows out of a central vent rather than the system of vents and can spread over a wide area before solidifying.
