What The Hell Is "Laze", A Hazard Of The Ongoing Eruption On Hawaii?


Robin Andrews

Science & Policy Writer

Lava from the Fissure 20 complex in the lower East Rift Zone enters the ocean. That white plume there is the "laze". USGS via Facebook

The United States Geological Survey’s (USGS) Hawaiian Volcano Observatory (HVO) is working 24/7 to ensure that lives are protected from the ongoing eruption at and around Kilauea. Remarkably, so far, there’s only been one serious eruption-related injury.

This isn’t easy when the hazards are so numerous, including a relative newcomer to proceedings: Named “laze” – a portmanteau of “lava” and “haze” – it started making an appearance on the Hawaii Emergency Management Agency’s social media accounts, and it’s safe to say it’s not a well-known term. So what exactly is it, and how does one avoid it?


Aside from the more explosive activity at Kilauea’s Halema’uma’u summit crater, most of the eruption’s danger comes from the lava-effusing fissures that have opened up across the East Rift Zone (ERZ). Although the paths of these lava flows are taking a wide range of routes across the region, some flows are – as is expected – terminating in the Pacific Ocean.


As they tumble into the sea, the lava cools vigorously, releasing a lot of steam. Within this steam is a bunch of hydrochloric and sulfuric acid droplets, as well as plenty of glassy, particularly fine volcanic ash particles.

That’s the “laze”. It’s often observed when Kilauea’s lava meets the sea, but as you may have noticed, there’s a hell of a lot more lava heading seaward than is normal at present. The uptick in laze production across a broader area, as well as people trying to get close to the eruption to witness its incandescent majesty, is likely triggering these new warnings.


Authorities note that unless you’re nearby the entry point into the sea – which you definitely shouldn’t be if you’ve been heeding proper warnings and instructions – then you’re not at risk. If you are, though, this laze can be dangerous.


The risks to a person are much the same as those posed by volcanic ash itself, if we put the collapse of building structures and the potential downing of planes aside. These acidic droplets, along with the glassy ash particles, can cause irritation of the eyes, throat, nasal cavities and skin.

Laze isn’t quite the same as volcanic fog (vog), an ash-lacking mixture of water vapor, CO2, and sulfur dioxide (SO2), which can react to form sulfuric acid droplets. Saying that, “vog, volcanic ash, and laze all have comparable hazards,” Dr Janine Krippner, a volcanologist at Concord University, told IFLScience.

“Volcanic ash is also composed of glass, and vog has the toxic aspect of it.”

Although everyone is potentially at risk if encountering them, “these hazards are going to affect people with pre-existing respiratory issues like asthma (even if they did not know they had it beforehand) and COPD [chronic obstructive pulmonary disease]. They can cause inflammation and can make breathing difficult.”


All are rarely lethal, but it is worth pointing out that back in 2000, laze exposure killed two people.

Being cautious, the Hawaii County Civil Defense Agency is prohibiting access to the ocean lava entry area due to this laze. They’re also emphasizing that the concentrations of SO2 around said entry points and along certain fissures in the ERZ are extremely high.


“Volcanic gas emissions have tripled as a result of the voluminous eruptions from Fissure 20 so SO2 concentrations are likely elevated to higher levels throughout the area downwind of the vents,” the USGS note in their latest advisory.

In fact, spikes of 100 parts per million of SO2 have been detected in some parts, which represent a clear threat to life. Exposure of >5 parts per million for just 15 minutes – something possible in downwind areas of Lower Puna – is enough to be described as “hazardous” and can cause respiratory issues.


The mantra here is the same as ever: don’t take risks, avoid these hazards, pay attention to authorities, and don’t believe the bullshit rumors you see online.


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