Aurora glimpsed through lava caveWhen hot fluid basaltic lava is erupted it frequently follows a seq

Aurora glimpsed through lava caveWhen hot fluid basaltic lava is erupted it frequently follows a sequence whereby the initial flow will be on the surface, but as the top layer begins to cool on contact with the air (some 1200 degrees Celsius temperature gradient) a crust of lava begins to form. As the crust thickens, a river of lava continues flowing beneath, sometimes for large distances. When the eruption ends the lava flows out the river empties leaving behind a lava tube (aka lava cave) that can be many miles long. While Hawaii boasts some fine ones complete with tropical ecosystems, but you might be hard pressed to glimpse aurorae, being too far south. For that you need to go to Iceland, where you might be cold, but also be lucky enough to catch (and snap) a glimpse such as this one. A word of warning: Be very careful walking on fresh lava flows, as there may be weak areas on seemingly solid rock, and one thing you definitely don’t want is to dip your leg into flowing lava, however briefly. Vulcanologists use a variety of probes and poke their way carefully across the landscape during fieldwork.LozImage credit: Ingólfur Bjargmundsson -- source link

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