Tag: eruption
Scientists studying Hawaii’s Mauna Loa volcano are optimistic about a ‘relatively chill’ eruption
The hazards attached to the eruption of Hawaii’s Mauna Loa volcano appear to be mostly under control — promising news for volcanologists, who have been waiting decades for an opportunity to derive data from such a well-observed major eruption without the impediments that come from constant danger.
Mauna Loa is the biggest volcano in the world — measured by area, not destructive capacity — and it’s currently seeing its first eruption since 1984.
“These kinds of events are always super exciting,” said volcanologist Kenneth H. Rubin at the University of Hawaii.
“There are two sides to the general discipline of studying really hazardous natural events,” Rubin said. First and foremost are hazards, and second are the events’ “inherent scientific interest.”
“The Mauna Loa volcano, and Kilauea volcano right next door, are among the best monitored and most frequently erupting volcanoes in the world,” Rubin said. He also noted that The Hawaiian Volcano Observatory is, “the oldest modern volcano observatory on the planet,” and that he and his colleagues have worked hard to “improve the predictability of how eruptions will evolve, if not when they will initiate.”
In other words, they’ve been waiting a long time, and focusing much of their attention on the dangers. But now, all that work may have finally given scientists a chance to focus on the eruption purely as a natural phenomenon, which is a potential boon for everyone’s safety in the long run.
What the Mauna Loa eruption could teach us
As Rubin explained, this is a potential perfect storm of data from satellites, direct observations from the ground, thermal and gas sensors, and — one of Rubin’s own specialties — observations derived from radiation.
As scientists get up close and personal with this lava, they’ll ask things like “Does it have crystals?” according to Rubin, since crystallization of magma helps drive eruptions.
Alternatively “Is it all glass?” Rubin asked, because that would have important impacts on lava viscosity — making it more or less runny, and potentially allowing scientists to more easily calculate dangers.
“How big are the bubbles?” is another question Rubin is asking. Bubble size and density in the magma chamber appears to be a strong determiner of when an eruption will stop.
Prime among the questions Rubin said he’ll be eager to explore is: “Where did this magma come from exactly?”
He explained that Mauna Loa has been seen as ripe for an eruption for years. “We have evidence that magma was injected [relatively recently] and didn’t erupt.”
Learning which magma came from where, and thus, how that not-yet-erupted magma interacts with the fresher magma coming from the mantle, could unlock valuable secrets about the nature of eruptions to come.
As volcanologist and frequent TV talking head Jess Phoenix told the Atlantic on November 29, “This is going to provide us with information on how volcanic eruptions evolve and unfold. And hopefully, we can use this information to help inform public-safety decisions both in Hawaii and around the world.”
Mauna Loa has been erupting for several days as of this writing, with lava emerging from two fissures, which is dribbling lava in a generally northeastern pattern. As of Monday, all that molten rock was gradually creeping toward the Daniel K. Inouye Highway, part of a crucial road system connecting the east and west coasts of the Big Island — but an actual lava-road collision was still about two miles out.
Credit: USGS / public domain
It’s still looking plausible that the lava will make contact with the highway according to a Monday statement from the United States Geological Survey (USGS). However, as of last Thursday afternoon, the flow was slowing down, so road closures won’t come as a surprise, and major interference with life on the Big Island is not looking likely.
Additionally, by Sunday the threat of ash being spewed into the air had dissipated, and the USGS’s aviation warning was downgraded from code “RED” to code “ORANGE.” Pilots, in other words, can be less worried than before about particles from this eruption damaging their engines.
By contrast, during the Kīlauea volcano’s lower Puna eruption in the summer of 2018 — the last Hawaii eruption of comparable magnitude — the volcano repeatedly blasted people with devastating lava bombs and caused $800 million in property damage, including the slow motion destruction of entire tracts of homes.
See the Hawaii volcano eruption from a safe distance
Even if habitations aren’t under threat, curiosity from ever-present sightseers in Hawaii is another hazard at times like this.
USGS, for its part, has been cautious, and duly tweeted warnings. But it has also recommended that Twitter users “get good views all day” from its webcams. According to the Dec. 1 statement from USGS about the eruption, “No property is at risk currently.”
“Some people joke that Hawaii volcanoes are drive-up volcanoes,” Rubin said. But he pointed out that Mauna Loa is at an altitude where the weather is cold, and the lava source isn’t positioned for easy access by vulnerable members of the public.
Also, Mauna Loa’s sheer size, and the gentle slope of the mountain place it at a refreshingly safe distance from most sightseers. Plus, the lava is “relatively runny, and not particularly high in gases.”
“All four of those things work together to make it relatively chill,” Rubin said.
Still, Rubin said, past hazards like “car-sized bombs,” “pyroclastic deposits,” and the threat of toxic gases mean it’s important to be cautious as the eruption takes shape.
Volcano’s massive eruption broke another impressive record
The story of an underwater volcano’s historic eruption keeps getting wilder.
In January 2022, the Hunga Tonga-Hunga Ha‘apai blast in the South Pacific sent pressure waves around the planet, astonishing scientists. Months later, researchers learned the explosion blew a whopping 58,000 swimming pools worth of water into the atmosphere — an unprecedented amount. Now, volcanologists determined the explosion’s plume of ash and water reached over 35 miles high. That’s the highest ever observed.
“It’s an extraordinary result as we have never seen a cloud of any type this tall before,” Simon Proud, a research fellow at the National Centre for Earth Observation in the UK and the study’s lead author, said in a statement. The research was published this week in the journal Science.
The powerful eruption easily blew through the lower part of the atmosphere, where we live and experience weather, called the troposphere (it reaches around 7.5 miles high). Then, it even pushed through the lofty stratosphere — a largely cloudless and weather-less realm — which reaches some 31 miles high. The plume ultimately entered the mesosphere, where most meteors burn up. As Proud tweeted, that’s “more than half way to space!”
“It’s an extraordinary result.”
To figure out the extraordinary height of Hunga Tonga-Hunga Ha‘apai’s plume, the researchers used images gathered from three different weather satellites operated by three different nations: The U.S.’s GOES-17, Japan’s Himawari-8, and South Korea’s GK-2A. The pictures, sent back every 10 minutes, allowed the team to see the great blast from a variety of angles, and ultimately deduce the volcanic cloud’s height.
These advanced satellites, however, didn’t exist during previous monstrous eruptions, like Mount Pinatubo’s violent blast in 1991. With decades-old observational abilities, scientist found that plume reached 25 miles high, but it wasn’t even the most powerful eruption of the 20th century. So other explosions may have reached the mesosphere, too. “Our research shows that previous eruptions, like Pinatubo in 1991, that weren’t seen by these advanced eyes in space probably went higher than we previously thought: Scientists couldn’t see the volcano from multiple angles and didn’t have frequent enough images,” Proud noted online.
Where did Hunga Tonga-Hunga Ha‘apai get all its volcanic power? It’s a submarine volcano, meaning the basin where the eruption occurs is underwater. It lies nearly 500 feet under the surface, giving the eruption vast amounts of water to violently blow into the sky. While an impressive show of nature, this eruption won’t have a long-lived climate impact. Water vapor is indeed a potent greenhouse gas that traps heat, but this temporary water vapor impact will “not be enough to noticeably exacerbate climate change effects,” NASA said.
Crucially, today’s climate change is largely driven by human actions, not natural events like volcanic eruptions.
This event, which delivered bounties of awe, was one of the most powerful eruptions ever observed. Understanding Hunga Tonga-Hunga Ha‘apai’ will help scientists better grasp what such volcanoes are capable of, and better warn people (and planes) about the looming impacts.