Why Kilauea’s Eruption Makes Volcanologists Nervous

SCIENCE

It’s not exactly the sudden explosion that many Americans imagine when they hear the words volcanic eruption. But for exactly that reason, “it’s the kind of eruption that makes volcanologists nervous.” (The Atlantic)

Use our activity to help students investigate how Kilauea’s erupts.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

 

Discussion Ideas

Kilauea is one of five volcanoes on the “Big Island” of Hawaii. The current eruptions on Kilauea are centered around the Pu’u O’o volcanic cone in the volcano’s eastern rift zone.
Map by Matt Chwastyk, National Geographic

  • The great big Kilauea volcano is erupting with lava, volcanic gas, and volcanic ash. Where is Kilauea?
    • Kilauea is one of the five volcanoes that make up the “Big Island” of Hawaii. Three are active, two are dormant.
      • active. Kilauea, Mauna Loa, and Hualalai, on the southern part of the island, are all active volcanoes. Kilauea is the youngest and most active volcano, and has been erupting continuously since 1983. Mauna Loa last erupted in 1984. Hualalai last erupted in 1801.
      • dormant. Mauna Kea and Kohala, to the island’s north, are dormant volcanoes. Measured from its seafloor base, Mauna Kea is the tallest mountain on Earth. It last erupted about 5,000 years ago. Kohala is the oldest volcano on the Big Island, and last erupted more than 100,000 years ago.

 

 

Mauna Loa, Kilauea, and the undersea volcano Loihi sit on top of the Hawaiian hotspot. For now.
Map by Joel E. Robinson, USGS

Kilauea’s newest fissures are approximately where the arrow for “lava tube” is on this diagram.
Map by J. Johnson, USGS

  • Kilauea and the rest of Hawaii’s active volcanoes sit over a hot spot. What makes hot spot volcanism unique? Skim our reference resource on hot spots for some help.
    • Hot spot volcanism is unique because it does not occur at the boundaries of Earth’s tectonic plates, where all other volcanism occurs. Instead, hot spot volcanism occurs at abnormally hot centers known as mantle plumes. Scientific models depict these plumes of molten rock almost like a lava lamp, with a rising bulbous head fed by a long, narrow tail that originates in the mantle.
      • Other hot spots likely include the Yellowstone hot spot (North American plate) and the Galapagos hot spot (Nazca plate).
      • While a hot spot remains relatively stable, the tectonic plate above it continues to move and shift due to its relationship with other plates and the rocky interactions in the mantle around it.

 

 

Fissure 7, above, was active for several hours on Sunday. The lava flow cut a rocky black path through the Leilani Estates subdivision.
Video by U.S. Geological Survey

  • What volcanic hazards are associated with the newest eruption of Kilauea? Take a look at this article from the good folks at the USGS for some help.
    • volcanic ash. Hours before Kilauea erupted with lava, it spewed a plume of pink ash hundreds of meters into the air. Wind can disperse ash dozens or even hundreds of meters across the island or ocean. Volcanic ash can make breathing difficult and can cause buildings and structures to collapse, damage agricultural crops, and contaminate grass used for livestock feed. The downwind ash plume from such eruptions also poses a hazard to aircraft.
      • Why was the plume pink? It rusted. The iron-rich minerals in Kilauea’s Pu’u O’o crater interact with oxygen in a process called oxidation, turning the ash pink.
    • volcanic gas. Among the gases emitted by erupting volcanoes are sulfur dioxide, which can be toxic to breathe and a corrosive on eye and skin contact. Sulfur dioxide, water vapor, carbon dioxide, and other components of volcanic gas are also major contributors to global warming, the current period of climate change.
    • fissures. Volcanic fissures are vents through which lava erupts, usually without explosive activity. Although Kilauea’s summit crater has experienced explosive eruptions, the most devastating aspect of the current activity is the series of 10 fissures that have opened on the volcano’s east flank.
    • fractures and subsidence. Moving magma, eruptions, the formation of fissures, and ground shaking from strong earthquakes produce an abundance of ground fractures and subsidence features that profoundly affect the landscape, human activity, and infrastructure such as roads and bridges.
    • earthquakes. Kilauea contributed to a magnitude 6.9 earthquake last week, followed by a series of magnitude 4-5 aftershocks. Such quakes can damage buildings, roads, bridges, and utilities. In Hawaii, damage can be intensified by water-saturated soils that amplify earthquake ground motions. On steep slopes, intense shaking may cause such soils to fail, resulting in landslides and mudflows.
    • lava flows. Lava flows destroy everything in their paths—rain forests, buildings, roads, utility and communication systems, and whole communities. The newest lava flows of Kilauea have already destroyed 26 homes in less than a week.
      • Lava entering the ocean presents its own set of hazards: Sudden collapse of a lava delta (new land created at ocean entry) and the adjacent sea cliff into the ocean, waves of scalding hot water, and steam plumes that can rain hydrochloric acid and tiny volcanic glass particles.

 

 

 

This amazing thermal map clearly shows lava spreading northward from Kilauea’s newest fissures. Temperature in the thermal image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The gray linear features are the other fissures (numbered in red color) that have erupted thus far in the sequence.
Map by U.S. Geological Survey. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe.

  • If people can safely walk away from Kilauea’s lava domes and runny lava, why are the fissures and eruptions making volcanologists nervous?
    • displaced people. More than 1,700 residents have been evacuated from communities on Kilauea’s eastern flank. If the fissures keep oozing lava, the evacuations may be permanent. That’s a lot of environmental refugees.

 

TEACHERS TOOLKIT

The Atlantic: Why Hawaii’s Newest Eruption Makes Volcanologists Nervous

USGS: Volcano Hazards Program-Kilauea

USGS: Volcano Hazards Program-Hazards

Nat Geo: Types of Volcanic Eruptions

Nat Geo: What is a volcano?

Nat Geo: What is a hot spot?

Nat Geo: What is volcanic ash?

Nat Geo: What is magma?

Nat Geo: Hawaii Geology

2 responses to “Why Kilauea’s Eruption Makes Volcanologists Nervous

  1. Pingback: Why Guatemala’s Volcano Is Deadlier Than Hawaii’s | Nat Geo Education Blog·

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