Kilauea’s volcanic fireworks show no signs of stopping | Science News for Students

Kilauea’s volcanic fireworks show no signs of stopping

From lavanadoes to laze and vog, the ongoing eruption is a lesson in volcano vocabulary
Jul 31, 2018 — 6:45 am EST
a lava flow on Kilauea's lower east rift zone

Fiery rivers of lava pour out of fissure 8 on Kilauea’s lower east rift zone. The lava fills an open channel from which it flows swiftly toward the ocean.


July 4th fireworks have nothing on Kilauea.

The Hawaiian volcano’s latest outburst has entered its third month . But scientists are still watching Kilauea 24/7. Such constant monitoring provides danger warnings aimed at keeping those nearby safe. It also offers remote viewers the rare opportunity to observe the evolution of an eruption in real time. 

Magma within Kilauea’s summit crater — called Halema`uma`u — continues to drain and move toward the lower east rift zone. As a result, the crater floor has become increasingly unstable.

The U.S. Geological Survey has observed frequent rockfalls from Kilauea’s upper lip into the crater since mid-May. Each collapse triggers a small explosion. One of the largest explosions took place on June 30. That’s when a collapse-explosion cycle released energy equivalent to a magnitude 5.3 earthquake. 

A “Whomp!” and a slow-rising cloud of volcanic gas and ash marked that collapse. But the real pyrotechnics are underway along nearly two dozen fissures. These are vents in that lower east rift zone through which lava is erupting. Lava fountains spurting from two fissures, Numbers 8 and 22, are feeding most of the lava flows that are now pouring into the sea.

It’s hard not to stare slack-jawed at images of molten rock spurting into the air. Or gape at glowing, fast-moving rivers of lava rushing into the ocean. Or gawk at the tangles of Pele’s hair — wispy-sharp strands of volcanic glass. Check out these highlights of Kilauea’s show and the science (and volcanic vocabulary) we’re learning from them:

Hot vortex

Of nearly two dozen fissures, Number 8 is producing some of the most spectacular pyrotechnics. This fissure is at the eastern edge of the now devastated Leilani Estates neighborhood. Among the more dramatic special effects that can emerge at sites such as this is the lava whirlwind, or lavanado. (The word is a combination of “lava” and “tornado.”) Lavanadoes form much like the “firenadoes” that are associated with especially intense wildfires. In each case, intense heat (in this case, from the volcano itself) causes air to rise swiftly, forming a tall column. Strong winds can then cause the column to rotate. The winds in this lavanado dance with the molten rock before flinging the lava several meters away.

This whirlwind — partly made of hot lava — is called a lavanado. It’s seen swirling above one of Kilauea’s active fissures.

In the vog

A thick fog has been curling out of fissures, then seeps along the ground. Called vog, this volcanic smog forms as sulfur dioxide and other gases and particles seep out from the fissures and react with oxygen, water vapor and sunlight. Since Kilauea began erupting along its lower east rift zone (within Leilani Estates), scientists have warned people nearby to wear protective masks. The goal is to guard against their breathing too much of this naturally toxic air pollution.

Volcanic fog, known as vog, can aggravate health problems such as asthma.

Ropy rock

The kind of lava erupting from Hawaiian volcanoes is a molten basalt rock. The lava cools into two main types of formation. When the lava flows slowly, air cools its “skin.” Beneath that skin, though, the lava continues to ooze ahead, advancing toe by toe. The smooth, ropy skin and toe-shaped lobes are characteristic of pahoehoe lava. More swiftly flowing lava is known as Aa. It appears chunky and angular. That’s because faster-moving lava loses heat more quickly and becomes more resistant to flow. Instead of a slow, sinuous advance, the lava tears ahead, forming large, hardened chunks.

an photo of Pahoehoe lava
Pahoehoe lava has a characteristic texture that resembles rope.

Fast flow

Glowing torrents of lava fed by fissure 8 on Kilauea’s lower east rift zone jet through a channel at speeds of about 7.7 meters per second (17 miles per hour). Although USGS scientists shot this video June 19, the rivers continue to flow. Much like a river of water, lava moves most quickly through the center of a channel and more slowly along the edges. The reason: friction. Lava waves form as the molten rock sloshes through lava rapids, along its 13-kilometer (8-mile) journey to the sea.

A glowing river of lava races from fissure 8 on Kilauea’s lower east rift zone all the way to the ocean.
USGS/Science News/YouTube

On a boat

Also like many water rivers, lava rivers have occasional passengers. Lava boats are pieces of hardened lava that clump together and get carried downstream. These rafts of lava resemble boats on a waterway. As lava boats sail along, more pieces of cooling lava may glom onto them, boosting their size. These then form accretions called lava balls.

A huge chunk of lava, named a lava boat, sails away on a river of lava from the Kilauea eruption. 
Ikaika Marzo/Facebook

Toxic steam

As Kilauea’s rivers of fire pour into the ocean, they boil the water. That sends great clouds of corrosive steam billowing into the air. The steam is a concoction that volcano scientists call laze, short for lava haze. It forms in a chemical reaction between the hot lava and seawater. At a temperature of about 1,150° Celsius (2,100° Fahrenheit), the lava basically boils away the seawater. That leaves behind very reactive sea salts (such as magnesium chloride). These salts react with the steam to form hydrochloric acid. Similar in strength to weak battery acid, laze can irritate eyes and skin. It can also cause breathing difficulties.

a photo of steam rising from the ocean as lava enters it
When lava enters the ocean, it chemically reacts with the seawater, creating a poisonous steam called laze.

Glass hair

When tiny droplets of lava spray into the air and rapidly cool, they can form fine threads of volcanic glass. Those fine threads are known as Pele’s hair. Pele is the Hawaiian goddess of fire and volcanoes. The fibers are so fine that they can be carried along by the wind before raining out. But it’s not a gentle rain. The sharp threads are abrasive enough to scratch car windshields and can irritate skin and eyes, or contaminate open water reservoirs.

a photo of the glass strands called Pele's hair
This is an example of Pele’s hair that formed during an eruption at Kilauea several decades ago. Such strands are also being formed by the current eruption.
D.W. Peterson/USGS/Wikimedia Commons     

Kilauea continues to spew fire and reshape Hawaii. On July 16, a chunk of rock the size of a basketball flew out of a fissure near the ocean and hit a passing tourist boat. That “lava bomb” injured 23 people. Meanwhile, a new delta made from lava is filling in what was once Kapoho Bay. This lava delta now spans more than 162 hectares (400 acres), USGS scientists say. That’s the equivalent of more than 300 U.S. football fields. And the lava pouring into the ocean has even created a brand-new, tiny island just north of the bay.


Power Words

(more about Power Words)

ash     (in geology) Small, lightweight fragments of rock and glass spewed by volcanic eruptions.

basalt     A type of black volcanic rock that tends to be very dense (unless volcanic eruptions seeded it with lots of air pockets). 

chemical     A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

chemical reaction     A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).

cloud     A plume of molecules or particles, such as water droplets, that move under the action of an outside force, such as wind, radiation or water currents. 

constant     Continuous or uninterrupted.

corrode     (adj. corrosive) A chemical process that weakens or destroys normally robust materials, such as metals or rock.

crater     A large, bowl-shaped cavity in the ground or on the surface of a planet or the moon. They are typically caused by an explosion or the impact of a meteorite or other celestial body. Such an impact is sometimes referred to as a cratering event.

downstream     Further on in the direction in which a stream is flowing or the path at which stream water will flow in its trek to towards the oceans.

earthquake     A sudden and sometimes violent shaking of the ground, sometimes causing great destruction, as a result of movements within Earth’s crust or of volcanic action.

eruption     (in geoscience) The sudden bursting or spraying of hot material from deep inside a planet or moon and out through its surface. Volcanic eruptions on Earth usually send hot lava, hot gases or ash into the air and across surrounding land. In colder parts of the solar system, eruptions often involve liquid water spraying out through cracks in an icy crust. This happens on Enceladus, a moon of Saturn that is covered in ice.

evolution     (v. to evolve) A process by which species undergo changes over time, usually through genetic variation and natural selection. Or the term can refer to changes that occur as some natural progression within the non-living world (such as computer chips evolving to smaller devices which operate at an ever faster speed).

fiber     Something whose shape resembles a thread or filament.

fissure     (in geology) A long, narrow opening that emerges in ice or rock. It starts when pressure causes the material to crack and eventually split open.

fog     A thick cloud of water droplets that touches the ground.

football field     The field on which athletes play American football. Owing to its size and familiarity, many people use this field as a measure of how big something is. A regulation field (including its end zones) runs 360 feet (almost 110 meters) long and 160 feet (almost 49 meters) wide.

friction     The resistance that one surface or object encounters when moving over or through another material (such as a fluid or a gas). Friction generally causes a heating, which can damage a surface of some material as it rubs against another.

geological     Adjective to describe things related to Earth’s physical structure and substance, its history and the processes that act on it. People who work in this field are known as geologists.

glass     A hard, brittle substance made from silica, a mineral found in sand. Glass usually is transparent and fairly inert (chemically nonreactive). Aquatic organisms called diatoms build their shells of it.

haze     Fine liquid or solid particles scattered through the atmosphere that make it hard to see. Haze can be caused by harmful substances such as air pollutants or by water vapor.

hydrochloric acid     A strong (potent) and corrosive acid formed when hydrogen chloride gas dissolves into water. The human gut produces a dilute solution of this to break down foods.

lava     Molten rock that comes up from the mantle, through Earth’s crust, and out of a volcano.

lava balls     Accumulations of cooling rock that can develop atop a stream of molten rock as it exits a volcano and flows across the land.

lava bomb     The popular term for a clump of molten rock hat can be explosively flung out of a pool of lava at the top of a volcano. It usually occurs when a gas bubble bursts at the pool’s surface. Extremely dangerous, it can melt through metal.

lavanado     A term created by combining “lava” and “tornado.” It refers to a whirlwind of lava. It forms when intense heat from the volcano causes air to swiftly rise into a tall column, then strong winds force it to rotate.

laze      A contraction of lava haze, it develops when hot lava reacts chemically with seawater. This haze is weakly acidic. It can irritate eyes and skin and cause breathing problems.

lobe     A rounded and somewhat flat projection. Many leaves, for instance, have lobed edges.

magma     The molten rock that resides under Earth’s crust. When it erupts from a volcano, this material is referred to as lava.

magnesium     A metallic element that is number 12 on the periodic table. It burns with a white light and is the eighth most abundant element in Earth’s crust.

magnitude     (in geology) A number used to describe the relative size of an earthquake. It runs from 1 to more than 8 and is calculated by the peak ground motion as recorded by seismographs. There are several magnitude scales. One of the more commonly used ones today is known as the moment magnitude. It’s based on the size of a fault (crack in Earth’s crust), how much the fault slips (moves) during a quake, and the energy force that was required to permit that movement. For each increase in magnitude, an earthquake produces 10 times more ground motion and releases about 32 times more energy. For perspective, a magnitude 8 quake can release energy equivalent to detonating 6 million tons of TNT.

molten     A word describing something that is melted, such as the liquid rock that makes up lava.

oxygen     A gas that makes up about 21 percent of Earth's atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).

particle     A minute amount of something.

Pele’s hair     (in geology) The popular term for the fine, wispy-sharp strands of volcanic glass that form when lava is stretched into incredibly thin fibers, often when a fountain of ejected lava cools as it sprays through the air. They are named for the Hawaiian goddess of fire and volcanoes.

pyrotechnics     A term for fireworks.

reactive     (in chemistry) The tendency of a substance to take part in a chemical process, known as a reaction, that leads to new chemicals or changes in existing chemicals.

reservoir     A large store of something. Lakes are reservoirs that hold water. People who study infections refer to the environment in which germs can survive safely (such as the bodies of birds or pigs) as living reservoirs.

rift zone     (in volcanology) An area where some volcano is splitting open, especially along its flanks. The rock here will be cracked and rather weak. That allows magma to push through it and to the surface. Once released from the rock, the lava will flow downhill, much as water would.

sea     An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.

smog     A kind of pollution that develops when chemicals react in the air. The word comes from a blend of “smoke” and “fog,” and was coined to describe pollution from burning fossil fuels on cold, damp days. Another kind of smog, which usually looks brown, develops when pollutants from cars react with sunlight in the atmosphere on hot days.

sulfur     A chemical element with an atomic number of sixteen. Sulfur, one of the most common elements in the universe, is an essential element for life. Because sulfur and its compounds can store a lot of energy, it is present in fertilizers and many industrial chemicals.

sulfur dioxide     A compound made of sulfur and oxygen. It is one of the pollutants that can form when a fossil fuel is burned. It’s also a gas naturally emitted during volcanic eruptions. Its scientific symbol is SO2.

summit     (in geology) The uppermost part of a mountain or hill, or (verb) the act of climbing and reaching that uppermost point. (in public policy) A meeting between officials of some organization or governments, often with the goal of negotiating new rules, policies or treaties.

toxic     Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.

U.S. Geological Survey     (or USGS) This is the largest nonmilitary U.S. agency charged with mapping water, Earth and biological resources. It collects information to help monitor the health of ecosystems, natural resources and natural hazards. It also studies the impacts of climate and land-use changes. A part of the U.S. Department of the Interior, USGS is headquartered in Reston, Va.

vent     (n.) An opening through which gases or liquids can escape. (v.) To free gases or liquids that had been under pressure. The term can also be used to release strong, pent-up emotions, such as anger.

vog     Volcanic smog that forms when sulfur dioxide and other gases and particles seep out of a volcanic fissure, then react with oxygen, water vapor and sunlight.

volcano     A place on Earth’s crust that opens, allowing magma and gases to spew out from underground reservoirs of molten material. The magma rises through a system of pipes or channels, sometimes spending time in chambers where it bubbles with gas and undergoes chemical transformations. This plumbing system can become more complex over time. This can result in a change, over time, to the chemical composition of the lava as well. The surface around a volcano’s opening can grow into a mound or cone shape as successive eruptions send more lava onto the surface, where it cools into hard rock.

water vapor     Water in its gaseous state, capable of being suspended in the air.

wave     A disturbance or variation that travels through space and matter in a regular, oscillating fashion.


Website: U.S. Geological Survey Hawaiian Volcano Observatory’s Kilauea page.