alt Hacker NewsIt’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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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).
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