Maxim


 * SHIELD VOLCANO: Muana Loa**

- It looks like a warrior's shield lying down, hence the name "shield" volcanoes.

- It is built almost entirely out of fluid lava flows. The lave pours out in all directions from a central summit vent, or group of vents. Over time and after thousands and thousands of magma flows, a broad, gently-sloping cone is built.

- Some of the largest volcanoes in the world are shield volcanoes. In northern California and Oregon, many shield volcanoes have diameters of 3 or 4 miles and heights of 1,500 to 2,000 feet. The Hawaiian Islands are composed of linear chains of these volcanoes including **Kilauea** and **Mauna Loa** on the island of Hawaii -- two of the world's most active volcanoes.

- Mauna Loa, the largest of the shield volcanoes (and also the world's largest active volcano), stands at 13,677 feet above sea level, its top is over 28,000 feet above the deep ocean floor.

- Shield volcanoes, such as Mauna Loa, erupt non-explosively, mainly pouring out huge of fluid lava. Hawaiian-type eruptions are rarely life-threatening because the lava advances slowly enough to allow safe evacuation of people, but large lava flows can cause considerable economic loss by destroying property and agricultural lands.

- Mauna Loa and, in fact, all of Hawaii is a geologically unique place on Earth because they are caused by a "hot spot." While most islands and many volcanoes are found at tectonic plate boundaries, Mauna Loa and all of Hawaii are right in the middle of the Pacific Plate and over a "hot spot." In a hot spot, the molten magma breaks through the weakest or thinnest part of the plate. In the case of Mauna Loa, the hot spot is under the sea floor and therefore produces undersea volcanoes. These volcanoes eventually build up to the surface and become islands.