Blue lava is a real phenomenon associated with some volcanoes. However, it’s not actually lava because it does not consist of molten rock. Here is a look at what blue lava is, how it works, and where you can see it for yourself.
What Is Blue Lava?
Some volcanoes and geothermal features have blue lava. The best-known is Kawah Ijen volcano in Indonesia. The blue lava is flame, rather than molten rock. It flows down the sides of the volcano like lava because the flame burns from molten sulfur or burning sulfur-containing gases that accompany lava.
Why Is Blue Lava Blue?
The true lava from Kawah Ijen is the usual reddish-orange color. Lava glows red-hot color from black-body radiation. In contrast, the electric blue of blue lava comes from the emission spectrum of sulfur. Heat gives sulfur atoms energy and excites their electrons. The electrons release photons as they return to a more stable energy. As in the flame test, the color is characteristic of the element.
Technically, molten rock or lava can be blue. However, it does not occur at natural volcano temperature. Blue lava from incandescence or black-body radiation requires temperature ranging from 1400-1650 °C (2600-3000 °F).
Where to See Blue Lava
The best place for viewing blue lava is the Kawah Ijen volcano. First, you travel to the island of Java in Indonesia. Once you reach the Ijen volcano, take a two-hour hike to the crater rim and another 45-minute hike to the crater bank. Tourist companies offer hikes occur at night, since the blue flame is not visible in the daytime.
Another place blue lava commonly occurs is on Dallol mountain in Ethiopia. Dallol is a hydrothermal system surrounding a cinder cone volcano. Its springs and fumaroles emit several gases, including hydrogen sulfide (H2S) and sulfur dioxide (SO2), which burn blue.
Sometimes blue lava forms at Yellowstone National Park in the United States. At Yellowstone, forest fires provide the energy that melts sulfur in geothermal areas. The resulting rives of blue lava are visible at night. If you examine the ground in the day, look for black lines that trace the melted sulfur.
Kilauea on the Big Island of Hawaii sometimes has blue lava, but the source is methane (CH4) rather than sulfur. The heat of the volcano ignites methane gas trapped underground. Methane burns with a blue flame.
Make Blue Lava
Sulfur is a colorful, inexpensive, readily available element. If you can’t travel to a volcanic region, just burn sulfur. The solid element is lemon yellow. It melts at a low temperature (115.21 °C or 239.38 °F) into a blood-red liquid that resembles lava. Burning it reveals the “blue lava” flame.
Make a Blue Lava Lamp
Making a blue lava lamp is another travel alternative. There are two easy options that are safe for kids.
For the first project, you need tonic water that contains quinine, a roll of Mentos candies, and a black light. At night or in a dark room, turn on the black light and illuminate the tonic water. It glows bright aqua blue. Drop the Mentos candies into the tonic water for the “eruption.”
The other lava lamp requires a clear plastic bottle (e.g., 1-liter bottle), vegetable oil, water, blue food coloring, and an Alka-Seltzer tablet. Fill the bottle most of the way full of vegetable oil. Add around a tablespoon of water and a few drops of blue food coloring. Break an Alka-Seltzer into pieces and drop the pieces into the bottle. Cap the bottle and enjoy the blue lava lamp.
- Grunewald, Olivier (December 8, 2010). “Kawah Ijen by night“. Boston Globe.
- Howard, Brian Clark (January 30, 2014). “Stunning Electric-Blue Flames Erupt From Volcanoes”. National Geographic News.
- Rakovan, J. (11 December 2015). “Word to the Wise: Blue Lava”. Rocks & Minerals. Miami University. 91 (1): 83–85. doi:10.1080/00357529.2016.1099138
- Rice, Doyle (May 25, 2018). “Blue flames of methane spotted near Hawaii’s Kilauea volcano“. USA Today.
- Siebert, Lee (2010). Volcanoes of the World. Simkin, Tom., Kimberly, Paul. (3rd. ed.). Washington, D.C.: Smithsonian Institution. ISBN 9780520947931.