Honestly, if you were watching the news in late 2022, you probably saw those glowing rivers of red snaking down a dark mountain and thought the Big Island was toast. It looked like something out of a disaster movie.
But here is the thing.
The Mauna Loa volcano eruption wasn't the chaotic catastrophe people outside of Hawaii assumed it was. For locals and geologists, it was a long-overdue reunion with Earth's largest active volcano. It had been quiet for 38 years—nearly four decades of silence that made some people forget just how massive this "Long Mountain" actually is.
The Night the Giant Woke Up
It started just before midnight on November 27, 2022.
If you were in Kailua-Kona that night, you could look up and see a surreal red glow illuminating the sky. It wasn't an explosion. You didn't hear a massive boom like a Hollywood volcano. Instead, it was a series of fissures opening up inside the Moku‘āweoweo summit caldera.
Lava began fountaining.
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At first, the USGS (United States Geological Survey) was on high alert. Why? Because Mauna Loa is unpredictable at the start. Historically, if the eruption stays in the summit, everyone breathes easy. But if it migrates into the Southwest Rift Zone, lava can reach the ocean and residential areas in South Kona in just a few hours. That is the nightmare scenario.
Luckily, by the morning of November 28, the "plumbing" shifted. The magma moved into the Northeast Rift Zone instead. This was a game-changer. The slopes on the northeast side are much gentler. Lava moving that way has to travel miles across a high-altitude plateau before it hits anything important.
Why We All Obsessed Over a Road
For two weeks, the entire world became obsessed with a single stretch of pavement: the Daniel K. Inouye Highway, known locally as Saddle Road.
This road is the main artery connecting the east and west sides of the Big Island. If the lava cut it, the island’s economy would have taken a massive hit. Commuters would have been forced to take the long way around—a coastal drive that adds hours to a trip.
Fissure 3 was the main "star" of the show. It was shooting lava fountains up to 200 feet into the air. It created a massive flow that crept toward the highway. At its peak, the lava was moving at a decent clip, but as the ground flattened out, it slowed to a crawl.
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It eventually stalled just 1.7 miles from the road.
The eruption officially ended on December 10, 2022. It just... stopped. The lava supply cut off, the glow faded, and the highway stayed perfectly intact.
The Science We Almost Lost
One detail that didn't get enough play in the mainstream media was the "Keeling Curve."
Up on the slopes of the volcano sits the Mauna Loa Observatory. It’s world-famous for measuring atmospheric carbon dioxide. When the lava started flowing, it actually buried about a mile of the access road and knocked out the power lines.
The scientists there were devastated.
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They lost the ability to take their primary measurements for the first time in decades. For a minute, it looked like a major gap in climate data was inevitable. However, the team scrambled and eventually set up temporary equipment on Mauna Kea (the neighbor volcano) to keep the record going. It was a close call for global climate science.
Common Misconceptions About the Eruption
- "It was a surprise." Not really. The USGS had been reporting "increased unrest" since mid-September. Earthquakes had jumped from 10–20 a day to over 50. The mountain was literally swelling.
- "The whole island was in danger." The Big Island is huge. Most residents in Hilo or Kona were never in physical danger from the lava. The biggest "threat" for most was the vog (volcanic smog) and Pele’s hair—thin strands of volcanic glass that can irritate your skin and eyes.
- "It’s a rare event." Historically, no. Between 1843 and 1950, Mauna Loa erupted every 3 to 4 years on average. The 38-year nap it took before 2022 was actually the weird part.
What This Means for Your Next Trip
If you’re planning to visit Hawaii Volcanoes National Park soon, don't expect to see active red lava from Mauna Loa. It’s back to "normal" (non-eruptive) status.
But you can still see the 2022 flows. They look like vast, silvery-black scars across the landscape. They are a stark reminder that the ground beneath your feet is alive.
When a Mauna Loa volcano eruption happens, the best thing you can do is stay informed through the Hawaiian Volcano Observatory. They are the gold standard for data. Don't rely on "viral" TikTok videos that might be using footage from the 2018 Kīlauea event.
Actionable Steps for the "Volcano Curious"
- Check the Air Quality: Use the Interagency Vog Dashboard if you have asthma or respiratory issues. Even when it’s not erupting, gas levels can shift.
- Respect the Closures: If a trail is closed, it’s not because the rangers are being "fun-killers." It’s because the ground is literally a hollow crust over a lava tube or the gas levels are toxic.
- Pack for "High Altitude": People forget Mauna Loa’s summit is over 13,000 feet. It snows up there. If you're hiking even the lower slopes, bring a jacket and plenty of water.
- Download the USGS "VSC" App: It gives you real-time alerts on seismic activity. It's a bit nerdy, but it’s the best way to know if the giant is starting to stir again.
Mauna Loa is currently inflating, which means magma is slowly refilling the reservoir. It isn't going to blow tomorrow, but it is "recharging." Living with a volcano means understanding it isn't a one-time event—it's a cycle.