Hawaii is literally growing. If you haven't looked at a before and after map Hawaii volcano comparison since 2018, you're looking at an outdated version of the United States. Most people think of "land" as something permanent, but on the Big Island, the map is more of a suggestion than a final draft.
I’ve spent hours pouring over USGS (United States Geological Survey) data and satellite imagery because the reality is much weirder than just "some lava flowed into the ocean." We’re talking about entire bays being replaced by black rock and a crater that basically swallowed itself whole.
The 2018 Reset: Kapoho Is Gone
The biggest shock to the system happened in 2018. Before that summer, Kapoho Bay was this idyllic spot for snorkeling and vacation rentals. If you look at a map from early 2018, you see a jagged coastline with tide pools and lush greenery.
Then Fissure 8 happened. Basically, a massive river of lava tore through Leilani Estates and headed straight for the sea. By the time it stopped, the "after" map showed something surreal:
- 875 acres of brand-new land created in the ocean.
- Kapoho Bay? Completely filled. Where there was once deep blue water, there is now a solid lava delta.
- The coastline pushed out by nearly a mile in some spots.
Honestly, it’s hard to wrap your head around the scale until you see the old roads just... ending at a wall of cooled rock. Over 30 miles of road were buried. If you try to use an old GPS in certain parts of the Puna district today, you’ll literally be driving through what the map thinks is the Pacific Ocean.
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The Summit Collapse: A 1,600-Foot Drop
While the coast was growing, the summit of Kilauea was doing the opposite. It was shrinking. Well, collapsing is a better word.
Before 2018, the Halema‘uma‘u crater was a relatively small "pit" within the larger caldera. You could stand at the Jaggar Museum and look down at a glowing lava lake. After the 2018 event, the "after" map of the summit looks like a giant took a scoop out of the earth.
The magma drained out of the summit to feed those fissures down in Puna. Without that "support" underneath, the crater floor dropped by as much as 1,600 feet.
The Jaggar Museum? It’s still there, but it’s closed forever because the ground underneath it is riddled with cracks. The National Park Service basically had to redraw every hiking trail map in the vicinity because the old ones would lead you right over a new cliff.
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The 2024-2026 Phase: Filling the Hole
Now, here is what’s happening right now in 2026. The volcano hasn't just sat there since the big collapse. Since late 2024, Kilauea has been in this "episodic" phase. It’s like a fountain that turns on and off.
Every time it "turns on," it adds a new layer of lava to the bottom of that massive 1,600-foot hole. Experts at the Hawaiian Volcano Observatory (HVO) say we've already refilled about 35% of the volume lost in 2018.
Wait, what about Mauna Loa?
You can't talk about Hawaii maps without mentioning the "Big Brother." In late 2022, Mauna Loa erupted for the first time in nearly 40 years. It didn't destroy houses like Kilauea did in 2018, but it came dangerously close to cutting off the Saddle Road (the main highway across the island). The "after" map for Mauna Loa shows a long, thin finger of lava stretching across the high-altitude plateau.
What You Need to Know for Your Next Trip
If you're planning to visit, don't rely on a paper map from five years ago. Seriously.
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- Check the USGS Live Maps: They update these almost daily during active flows. The "thermal maps" are especially cool because they show you where the heat is even if the surface looks like crusty old rock.
- The New "Pu‘u": As of January 2026, there’s a brand-new hill (a pu‘u) forming southwest of the Halema‘uma‘u crater. It’s grown dozens of feet in just a few fountaining episodes.
- The "Aina" is Unstable: That new land at the coast? It’s a "lava delta." It’s basically a pile of loose rubble with a hard crust on top. It can (and does) collapse into the sea without warning.
How to See the Changes Safely
The best way to actually witness these before and after changes is from the air. Helicopter tours out of Hilo or Kona are the only way to see the "new" coastline and the massive scale of the summit collapse in one go.
If you're on foot, head to the Volcano House or the various overlooks in Hawaii Volcanoes National Park. You can see the "down-dropped blocks"—massive chunks of the old caldera floor that sank during the collapse. It looks like a staircase for a titan.
Basically, the map of Hawaii is a living document. By the time you read this, a new eruption might have already added another few acres to the state.
Actionable Next Steps:
- Visit the USGS HVO website before you go to see the "Current Eruption Map."
- Download the NPS App for the most current trail closures; don't trust old blog posts for hiking info.
- Look for "Lava Tree State Monument" to see how older eruptions (from the 1700s) shaped the land, giving you a long-term perspective on how these "before and after" cycles work over centuries.