Instead, it has twists and turns, originally coming from the southeast, but then turning toward the west of Hawaii as the plume reaches into the shallower mantle. Seismic imaging by research teams I’m involved with has shown that Hawaii’s mantle plume comes from deep inside the mantle.īut the plume is not a straight pipe as some concept figures suggest. The origin of the magma may be more than 620 miles deep, and some scientists have suggested it could comes from a depth of 1,800 miles, where the mantle meets Earth’s core. If a large enough opening exists at the surface, and enough volcanic gases have collected in the magma chamber, the magma is forced to the surface in a volcanic eruption. Because the overlying pressure lessens as the rock ascends, it melts more and more, and eventually collects in the magma chamber. The ascending mantle rock is what makes a mantle plume. The partially molten rock becomes buoyant and ascends toward the surface. Mantle rock is solid at some places, while it starts to melt at other places. Instead, differences in the type of mantle rock make it melt at different temperatures. Scientists hypothesize that the mantle is not made of uniform rock. How does molten rock travel from deep in Earth’s mantle, and what exactly is a mantle plume? The same thing happens at Haleakala, on Maui, which last erupted about 250 years ago. Beneath Hawaii, magma can move upward through the cracks to feed different volcanoes on the surface. The crust and mantle that comprise the Pacific Plate cracks at different places as it moves northwestward. But volcanoes can also be in the middle of plates, as Hawaii’s volcanoes are in the Pacific Plate. Volcanoes typically occur where these plates either move away from each other or where one pushes beneath another. Robinson/USGSĮarth’s crust is made up of tectonic plates that are slowly moving, at about the same speed as a fingernail grows. We won’t be able to answer every question, but we will do our best.An illustration suggests what Hawaii’s mantle plume might look like. Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to Please tell us your name, age and the city where you live.Īnd since curiosity has no age limit – adults, let us know what you’re wondering, too. What’s critical: warning systems for lahars, planned evacuation routes in areas threatened by volcanoes, and excellent communication between the scientists at volcanic monitoring stations and government agencies who can let people know when a volcano is about to go. While we cannot predict the exact time of an eruption, scientists are learning more about what causes them, and how to protect people who live near them. People need an early warning of an eruption so they can move out of harm’s way. Generally, scientists don’t try to stop volcanoes from erupting. That could be an injection of new magma into the chamber, a buildup of gases within the volcano, or a landslide that removes material from the top of a volcano.īelow the surface, Earth is always moving and changing. Then something needs to trigger the eruption. Typically, for an eruption to occur, enough magma must accumulate in the chamber under the volcano. These signs suggested that more magma was making its way upward, because pressure from rising magma can expand the sides of a volcano and cause rocks to shift and break, which leads to earthquakes. In the months leading to its eruption, scientists noted increased earthquakes and a bulging of Mauna Loa, like a balloon being inflated. Once released from the volcano, the magma is called lava. The volcano is essentially an opening that lets magma out onto the surface of the Earth. The magma at Mauna Loa forms when a hot mantle plume – think of a conveyor of heat – partly melts rock in the mantle. Over time, magma – which is melted rock mixed with gas and mineral crystals – accumulates in an underground chamber beneath the volcano. The center of the Earth is called the core the next layer up is the mantle the outermost layer is the crust. Antonio Busiello/Moment via Getty Images How volcanoes blow their stacks 79, Vesuvius erupted and destroyed the city of Pompeii. Mount Vesuvius, about 6 miles east of Naples, Italy, is still an active volcano.
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