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Why can’t we throw all our trash into a volcano and burn it? – Georgina T.
It’s true that lava is hot enough to burn some of our trash. When Kilauea erupted on the Big Island of Hawaii in 2018, lava flows were hotter than 2,000 degrees Fahrenheit (1,100 Celsius). This is hotter than the surface of the planet Venus, and hot enough to melt many rocks. It’s also as hot as garbage incinerators, which generally burn garbage at a 1,800 to 2,200 F (1,000-1,200°C).
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But not all lavas have the same temperature. Eruptions in Hawaii produce a type of lava called basalt. Basalt is much hotter and more fluid than the lavas that erupt at other volcanoes, such as the thickest dacite lava which erupts on Mount St. Helens in Washington state. For example, the 2004-2008 eruption of Mount St. Helens produced a lava dome with surface temperatures less than about 1,300 F (704 C).
Besides temperature, there are other good reasons not to burn trash on volcanoes. First, although lava at 2,000 degrees F can melt many materials in our trash—including food scraps, paper, plastics, glass, and some metals—it is not hot enough to melt many other common materials, including steel, nickel and iron.
Second, there aren’t many volcanoes on Earth that have lava lakes, or bowl-shaped craters filled with lava, where we can dump trash. Of all the thousands of volcanoes on Earth, scientists only know eight with active lava lakes. They include Kilauea, Mount Erebus in Antarctica It is Nyiragongo in the Democratic Republic of the Congo. Most active volcanoes have craters filled with rocks and cooled lava, such as Mount Saint Helenaor with water, like Crater Lake in Oregon.
The third problem is that dumping trash into these eight active lava lakes would be very dangerous work. Lava lakes are covered by a crust of cooling lava, but just beneath this crust they are molten and intensely hot. If rocks or other materials fall to the surface of a lava lake, they will break through the crust, disrupt the underlying lava, and cause an explosion.
This happened at Kilauea in 2015: Blocks of rock from the crater rim fell into the lava lake and caused a huge explosion that ejected rocks and lava up and out of the crater. Anyone who threw trash into a lava lake would have to run away and dodge the trash and burning lava.
Suppose it were possible to safely dump trash into a lava lake: what would happen to the trash? When plastics, trash and metals burn, they release a lot of toxic gases. Volcanoes already emit tons of toxic gases, including sulfur, chlorine and carbon dioxide.
Sulfur gases can create acid fog, which we call “vog,” which means “volcanic fog.” He can kill plants and cause respiratory problems in people nearby. Mixing these already dangerous volcanic gases with other gases from burning our trash would make the resulting vapors even more harmful to people and plants near the volcano.
Finally, many indigenous communities consider nearby volcanoes to be sacred sites. For example, Halema’uma’u crater on Kilauea is considered the home of Pele, the native Hawaiian goddess of fire, and the area around the crater is sacred to native Hawaiians. Throwing trash into volcanoes would be a huge insult to these cultures.
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This article was republished from The conversation, an independent, nonprofit news organization that brings you trusted facts and analysis to help you understand our complex world. It was written by: Emily Johnson, US Geological Survey
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Emily Johnson receives funding from the US Geological Survey
