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Kilauea erupts, destroying webcam [video]

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581 points zdw | 5 comments | 06 Dec 25 23:39 UTC | HN request time: 0s | source
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sedatk ◴[07 Dec 25 09:48 UTC] No.46180489[source]▶
I was there today. We happened to notice the smoke over Kilauea while driving to Hilo, then checked out USGS cams, and immediately drove there and spent the next 7 hours getting mesmerized.

As my first eruption encounter, I didn’t expect to experience several things like the heat even from a long distance, enough to keep me warm in my shorts at 60F, and the loud rumble, like a giant waterfall. The flow of lava was way faster than I expected too, almost like oil.

Mind blown.

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1. kzrdude ◴[07 Dec 25 11:07 UTC] No.46180869[source]▶
Hawaii volcanism is what geologists seem to call "nice and friendly" - low viscosity lava, not prone to explosive eruptions (unlike the stratovolcanoes of the Andes or the Pacific rim in general) - this is because it's caused by hotspot volcanism in Hawaii.
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2. lazide ◴[07 Dec 25 15:40 UTC] No.46182477[source]▶
It’s not nice and friendly because of the hotspot volcanism.

It’s because the hotspot has a chemical composition that is generally low in dissolved gasses and very liquid/flows well. (Lots of silicates I think?)

It tends to come out nicely and stay liquid as it leaves, so vents don’t plug up. Also, because of the relatively low dissolved gasses, pressure doesn’t spike as high when it’s flowing out of the chamber like many other magmas do, causing explosions.

Hawaii exists basically because it’s great for building up islands/mountains without blowing them up as part of the process.

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3. kzrdude ◴[07 Dec 25 16:21 UTC] No.46182838[source]▶
I don't think hotspots can be said to have different composition. But if the hotspot is under a continent or an ocean plate makes a difference for the type of eruptions. Hawaii is in the middle of an ocean plate, no continental crust there. So we get a basaltic eruption (comparatively lower silica content, low viscosity lava).
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4. CGMthrowaway ◴[07 Dec 25 16:27 UTC] No.46182885[source]▶
Low viscosity is due to the LOW silica content. Tectonic setting is the primary factor determining the magma's final composition (basaltic) and therefore its physical properties (low silica, low viscosity). The gentle nature of Hawaiian volcanism is a direct result of its basaltic magma, which it has because the hotspot is located under thin, basaltic oceanic crust
5. s1artibartfast ◴[07 Dec 25 19:37 UTC] No.46184409{3}[source]▶
Yellowstone is also caused by hotspot volcanism. The friendly eruption is a property of location, not hotspot origin.

Your initial post read the other way, which the parent post is addressing.