Shield volcanoes can sometimes create lava tubes. In the blackness that engulfed the night, electric heat lit flowing streams that fell into the sea, disappearing in a cloud of steam with a sizzling splash.” - Victoria Kahler, from Capturing the Sunset “Mount Kilauea spilled glowing lava like cords of orange neon-lighting from seemingly nowhere. Mauna Loa is large with a massive and elongated base, but volcanoes found in Iceland, such as Skjaldbreiður, are much smaller than their Hawaiian counterparts. Since shield volcanoes can be created in multiple different ways, different shield volcanoes around the world will have different shapes to them. Eruptions of shield volcanoes can be explosive if water is able to get into the vent, or if some object obstructs vents. This means that the slopes of the volcano were formed by the accumulation of chunks of material over many different eruptions. However, some shield volcanoes are classified as pyroclastic shields. Lava flow from shield volcanoes frequently reaches local roadways as well, which can block them and prevent traffic. Yet since shield volcanoes frequently have eruptions that are prolonged, they can flow to areas a good distance away from the vent and damage structures. Lava flows from shield volcanoes do not typically threaten human lives since they usually follow easy to predict paths. This is what usually counts for their distinctive shield-like shape. The sheets of lava are usually thinner as well, due to the fact that they travel longer distances and are, hence, distributed.
Shield volcanoes that have broad profiles are likely to be created by multiple layers of basaltic lava that come out of vents.īecause the lava that flows out of shield volcanoes has a higher viscosity, it is usually capable of traveling greater distances than lava that erupts from either stratovolcanoes or cinder cone volcanoes. Lava that flows easily tends to produce shield volcanoes. Viscosity refers to the thickness of the lava, how much it resists being moved. Shield volcanoes are usually formed by lava flows that have low viscosity.
#Volcano viscosity definition series
Calderas can become crater lakes or exist in concentric circles near the top of volcanoes, having been created in a series of collapses over time.
Calderas are created when the magma chamber of a volcano is completely emptied and it collapses in on itself. Volcanoes can also generate other structures, like calderas. Other well-known shield volcanoes include the Alcedo Volcano in the Galapagos, Mount Wrangell in Alaska, and Rangitoto Island near New Zealand. Most of this size is below the ocean, only around 4,170 meters or 13,680 feet exist above sea level. Mauna Loa is approximately 1,700 meters (55,000 feet) high. The slope of a shield volcano resembles the shield of a knight, hence the name. The base of a shield volcano can be quite large, easily kilometers or miles in size. Lava frequently bubbles out of shield volcanoes and slopes down the volcano, spreading out in every direction from the vent. Shield volcanoes are known for their gentle slopes, which are the result of fairly low-key eruptions. Famous cinder cone volcanoes include Paricutin in Mexico and Mount Suribachi in Japan. Skildus, meaning “to divide, split, or separate”Ĭinder cone volcanoes tend to be rather small when compared to other volcanoes, with an average size of around 90 meters (300 feet), unable to rise more than about 366 meters (1200 feet). These little bits of lava are referred to as tephra, and after they land they rapidly cool at the volcano’s vent, meaning that a crater builds up at the summit of the volcano over time. They are also what people usually think of when they hear the word “volcano.” When cinder cone volcanoes erupt, they send bits of lava into the air. The Different Types of VolcanoesĬinder cone volcanoes are the most common out of all the different volcanoes in the world. Volcanologists separate volcanoes into three different categories: cinder cone volcanoes, stratovolcanoes, and shield volcanoes. Shield volcanoes are just one type of volcano. Yet how does a shield volcano work, and how does it differ from other volcanoes? Shield volcanoes like Mauna Loa are impressive to look at and study, because their eruptions are not usually violent, meaning they can be approached much more safely than other volcanoes. The largest volcano in the entire world, Mauna Loa in Hawaii, is a shield volcano. The low viscosity, runny, nature of the lava means it travels in streams far from the source and covers many square miles. A shield volcano is the largest type of volcano on Earth, with low viscosity lava flows and a wide broad shape.
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