USGS Scientists Use Crystals to Uncover Kilauea's Magma Secrets

Volcanic gases trapped in crystals provide clues about eruption hazards and magma storage depths.

Published on Feb. 15, 2026

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USGS Hawaiian Volcano Observatory scientists are using tiny gas-filled inclusions trapped within volcanic crystals to gain critical insights into Kilauea's underlying plumbing system. By measuring the density of carbon dioxide gas trapped in these fluid inclusions, researchers can estimate the pressure and depth at which the magma was stored before erupting at the surface. This technique provides an important new tool for understanding hazards during Kilauea's frequent eruptions.

Why it matters

Volcanic gases can offer vital clues about impending eruptions, but measuring gases below the surface is challenging. Analyzing the composition and density of gases trapped in crystals allows scientists to peer into the volcano's subsurface and better understand where magma is stored and how it behaves before reaching the surface. This knowledge is crucial for assessing and communicating volcanic hazards in Hawaii.

The details

USGS scientists use a technique called Raman Spectroscopy to measure the density of carbon dioxide gas trapped in tiny fluid inclusions within volcanic crystals like olivine. The density of the CO2 is directly related to the pressure and depth at which the inclusion was trapped as the crystal grew. By analyzing these fluid inclusions, researchers can estimate the storage depth of the magma before it erupted. Recent results from Kilauea indicate the magma was stored about 1 mile (1.5 km) beneath the surface, in the shallow Halema'uma'u magma chamber.

  • In 2025, HVO scientists conducted a workshop on fluid inclusion sample preparation and identification at the University of Hawaii at Hilo.
  • Preliminary results from episodes that span from mid-January 2025 to early July 2025 show the magmas came from about 1 mile (1.5 km) deep beneath the surface.

The players

USGS Hawaiian Volcano Observatory

A research organization that monitors and studies volcanic activity in Hawaii.

University of Hawaii at Hilo Geology Department

A university department that collaborates with HVO on volcanic research and provides opportunities for undergraduate students.

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What they’re saying

“During each new eruption at Kilauea, this technique provides another important tool for HVO scientists to understand hazards in Hawaii's frequent eruptions.”

— Heather Winslow, HVO post-doc researcher (hawaiitribune-herald.com)

What’s next

HVO scientists will continue to analyze fluid inclusions from recent Kilauea eruptions to refine their understanding of magma storage depths and better assess eruption hazards.

The takeaway

By unlocking the secrets trapped within volcanic crystals, HVO researchers are gaining unprecedented insights into Kilauea's subsurface plumbing system, which is crucial for monitoring and communicating volcanic hazards in Hawaii.