What Is Laze? The Dangerous Lava-and-Haze Volcanic Plume

Laze: Understanding the Dangerous Mixture of Lava and Haze

When fiery molten lava streams from an erupting volcano and pours into the cold expanse of the ocean, a new and hazardous atmospheric phenomenon emerges: laze. Short for ‘lava haze,’ laze is a steam-laden, acidic plume brimming with toxic chemicals and microscopic shards of volcanic glass. In recent years, particularly during Hawaii’s Kīlauea eruptions, laze has dominated headlines as scientists and authorities urge the public to comprehend and respect its dangers.

What Is Laze?

Laze is a word blending the terms ‘lava’ and ‘haze,’ used to describe a noxious steam plume that forms when hot, flowing lava makes contact with the cooler ocean water. The result is a white, billowing cloud heavy with hydrochloric acid, steam, and particles of volcanic glass. This pungent, toxic mixture is exceptionally hazardous in the immediate vicinity of the ocean entry point and can linger downwind, affecting air quality and posing serious health risks.

The phenomenon is particularly prevalent at volcanic sites where lava regularly enters bodies of water, notably along the coasts of Hawaii’s Big Island during Kīlauea eruptions. Scientists from the USGS and other organizations monitor laze closely, especially during active eruptions, due to its rapid formation and shifting wind-driven patterns.

How Does Laze Form?

The formation of laze is a rapid, dynamic chain of physical and chemical reactions:

• As molten lava at temperatures reaching 1,200°C (2,200°F) spills into the cold ocean, an intense heat transfer occurs.
• Seawater rapidly boils away, producing copious amounts of steam.
• This process causes the decomposition of water molecules into hydrogen and oxygen.
• Chloride ions in seawater react with hydrogen to form hydrogen chloride gas (hydrochloric acid).
• Simultaneously, the explosive heat shatters lava into tiny shards of volcanic glass that become suspended within the steam plume.

The resulting laze plume rises and is carried by the wind, producing noticeable whitish clouds above the shoreline and, under certain conditions, drifting inland where it can impact populated areas twenty or more miles away.

Chemical Composition of Laze

Laze is a hazardous cocktail for several reasons. Its principal components include:

• Steam (H₂O): The main visible component of the laze plume.
• Hydrochloric Acid Gas (HCl): Formed when hydrogen produced by the thermal decomposition of water combines with chloride ions in seawater.
• Microscopic Volcanic Glass Particles: Fragments of fast-cooled, shattered lava, often called volcanic ash or glass shards.

These constituents make laze highly acidic and corrosive, with the hydrochloric acid content resulting in rain with a pH as low as 1.5 to 3.5—comparable in acidity to diluted battery acid.

Impacts on Human Health

Authorities and health experts warn that exposure to laze can be highly dangerous, even life-threatening in some cases. The dangers include:

• Eye Irritation: The plume’s hydrochloric acid and volcanic glass can severely irritate or burn eyes.
• Respiratory Distress: Inhalation of acidic steam and glass particles can damage lung tissue, causing coughing, wheezing, or serious respiratory issues.
• Skin Burns: Direct contact may result in acidic burns or rashes.
• Long-Term Health Effects: Repeated or significant exposure increases risks for chronic respiratory and eye conditions.

Wind can transport laze plumes unpredictably. Localized but intense, the worst conditions occur at the ocean entry and immediately downwind. According to the US Geological Survey, laze contributed to fatalities in documented cases, illustrating the very real peril of disregarding safety protocols in affected regions.

Environmental Effects of Laze

Laze is not only a threat to people; it can also have considerable impacts on environmental conditions and local ecosystems:

• Acid Rain: The acidic plume may result in localized acid rain, with corrosiveness similar to weak battery acid, potentially damaging vegetation and contaminating water supplies.
• Water Chemistry Changes: The influx of lava and associated gases alters the chemical properties of coastal waters, impacting marine life—including coral reefs, fish larvae, and other sensitive organisms.
• Hazard Zones: Acidic residue may settle on nearby land, affecting both natural ecosystems and human infrastructure due to its corrosive action.

Laze vs Vog: What’s the Difference?

While laze and vog (volcanic smog) both arise from volcanic activity, their causes, chemical makeup, and health risks are distinct:

Laze requires the unique interaction of molten lava and seawater, while vog is a more common product of volcanic gas emissions. Both are hazardous and can move quickly over great distances depending on wind patterns.

Other Related Volcanic Hazards

Volcanoes produce a variety of airborne hazards beyond just laze and vog. Understanding these phenomena is essential for overall volcanic risk awareness:

• Volcanic Ash:
  • Consists of tiny fragments of pulverized rock, mineral crystals, and volcanic glass—all less than 2 mm in size.
  • Sharp, abrasive, and dense—unlike campfire ash; can cause heavy, sand-like deposits during eruptions.
• Tephra:
  • General term for all types of volcanic projectiles, from ash to large lava bombs. Includes lapilli (2-64 mm).
• Spatter and Spatter Ramparts:
  • Lava blobs ejected near vents that accumulate to form substantial rock barriers.
• Pele’s Hair and Pele’s Tears:
  • Hair-thin threads of volcanic glass and hard glassy droplets, respectively, named after Hawaii’s volcano goddess. Can be carried far by the wind and also pose inhalation and eye hazards.

Public Safety Guidelines and Recommendations

Because of the rapid onset and unpredictability of laze plumes, safety is paramount near volcanic shorelines. Experts recommend:

• Avoiding ocean entry points during active eruptions entirely.
• Heeding local authority warnings and posted barriers.
• Remaining upwind and at a significant distance whenever possible—at least several hundred meters, as laze plumes dissipate quickly but are lethal at high concentrations.
• Wearing respiratory and eye protection if required to be in potentially affected zones.
• Being mindful of shifting wind conditions, which can cause plumes to move suddenly over new areas.

Emergency responders and the US Coast Guard often tightly restrict access, allowing only credentialed scientific teams or specifically permitted vessels into hazard areas.

Frequently Asked Questions (FAQs)

Q: How quickly does laze form when lava enters the ocean?

A: Laze plumes form almost immediately as molten lava hits seawater, due to the intense temperature differential and rapid chemical reactions involved.

Q: Can laze travel far inland?

A: Laze is usually most hazardous at the coastline and nearby downwind areas. However, strong winds can sometimes carry laze several miles inland, temporarily impacting air quality further from the eruption site.

Q: What should you do if you’re exposed to a laze plume?

A: Leave the area and move upwind or to a sheltered, enclosed space immediately. If symptoms such as difficulty breathing, coughing, or skin/eye irritation develop, seek medical attention promptly.

Q: Why is laze considered more acutely dangerous than vog?

A: Laze plumes have very high concentrations of hydrochloric acid and volcanic glass, making them immediately corrosive and harmful. Vog’s effects are usually less acute but more chronic, primarily threatening those with pre-existing respiratory problems.

Q: Has laze exposure ever been fatal?

A: Yes, there are instances where people have died after being exposed to high concentrations of laze, underscoring its lethal potential.

Conclusion

The mesmerizing spectacle of lava entering the ocean belies its serious hazards. Laze is a potent reminder of both nature’s beauty and its capacity for destruction. By understanding what laze is, how it forms, and the risks it poses, communities and visitors can better protect themselves and respect the power of volcanoes. Ongoing scientific monitoring and public education are key to minimizing harm during volcanic events.