The ongoing eruption at Kilauea continues to delight the senses while keeping everyone working at the Hawaiian Volcano Observatory (HVO) from getting a single good night’s sleep. It’s also proving to be a boon for volcanologists, who – apart from shooting down bonkers rumors 24/7 – are becoming living dictionaries, explaining what all these strange, cool-sounding eruption terms mean.

From furious lava fountains to the acidic, glassy, potentially deadly laze, it’s been fun. Now, courtesy of the United States Geological Survey’s (USGS) fabulous Twitter feed, we have another that’s cropped up: “curtain of fire.” Although hardly a rare sight during such eruptions, a spectacular video clip released over the weekend has brought the phenomenon back into the spotlight.

It’s essentially a prolonged, long, thin series of lava fountains. For those not in the know, lava fountaining describes rhythmic, vertical streams of fresh lava shooting up from a volcanic vent or fissure. There are plenty of ways in which you can generate a lava fountain, but in general, it requires fluid, less viscous magma containing plenty of gas. When this reaches the surface world, the gas expands so rapidly it forces the lava out with considerable force.

This can sometimes involve gloopier magma and a giant “slug” of gas popping at the surface. At Kilauea, however, as of late, this has involved near-continuous streams of gas flinging sizeable chunks of lava skywards, along both old and new fissures in the lower East Rift Zone (ERZ) on the volcano’s flanks.

A curtain of fire is, then, a prominent display of lava fountaining. It’s described by Oregon State University as “a row of coalescing lava fountains along a fissure,” adding that it’s a “typical feature of a Hawaiian-type eruption.”

They are nothing if not impressive. In the latest video, lava fountains within such curtains are seen reaching heights of at least 60 meters (196 feet), about that of a 15-story building. Imagine seeing that from your office or flat window!

The dangers to everyone from these curtains of fire are exactly the same as from individual lava fountains: lava blebs, which weigh a lot more than you might imagine, can land on you and both crush and melt whatever part of your body it impacts. Although you’d have to be fairly close to them to be at risk, it’s advised to keep at a considerably safe distance from them or any fresh lava flow which you can easily fall through or into.

Otherwise, the eruption hasn't generated many plot twists over the last 24 hours or so. Although Kilauea’s summit crater is increasing in size, this isn't particularly surprising: The intermittent explosive activity there is weakening the surrounding rock, and the draining of the lava lake and underlying magmatic reservoir has removed mechanical support from the steep crater walls.