Kilauea’s not making headlines like it used to, and this is somewhat understandable. Apart from the occasional footage of a “volcanic tornado”, it’s not changing its rhythm at present: lava continues to ooze from Fissure 8, fine glassy fragments of “Pele’s hair” are still raining down around the fissure’s seaward lava channel, and acidic laze plumes continue to rise up from the sea.
This may be the new normal, but Hawaii hasn’t run out of magmatic magic tricks just yet. Kilauea just demonstrated this rather beautifully by not only creating a new island offshore, but by taking it away again just hours later.
So what is it, and where did it come from – and where did it go?
Photographs from July 13-14 revealed that the island, still oozing fresh lava, had been spotted by the United States Geological Survey (USGS) on the northern end of the current lava entry point around Kapoho Bay. Although it’s not clear what size it is from the aerial photographs, it’s safe to say that it is, or rather was, incredibly small.
It’s worth emphasizing that this isn’t a new volcanic island forming in the way that you might think.
In places around the world – and indeed, in the Hawaiian archipelago – rapid, persistent, voluminous effusions of lava from the seafloor can rise up into the sky and form a new island. As with the new delta forming in Kapoho Bay, the land survives if the rate of geological creation outpaces the rate of marine erosion.
Kilauea – fueled by a rising, superheated mantle plume creating plenty of melting in the overlying crust – may be the center of volcanism on Big Island at present, but a new seamount, an underwater volcano, is forming offshore. Named Loihi, it will one day become the new center as the Pacific Plate drifts atop the stationary plume.
In 10,000 to 100,000 years, Loihi will rise up above the waves and become the new, dominant land volcano. That is not what this new, currently unnamed island is.