A week or so back, after the AAS meeting ended, we went to the Big Island of Hawai’i for some site visits to observatories (I had a few clients to meet with) and a chance to do a little hiking during our free time. The major hike was across a few miles of lava flows that have been successively laid down over the past decade or so from the Pu’u O’o vent on the flanks of Kiluaea volcano. I’ve done the lava study field trip a couple of times, and Mr. SpaceMusic and I have hiked older flows together, but he had never been “up close and personal” with a lava flow before. So, we contacted a colleague of mine from the old Sky & Telescope days, Stephen James O’Meara, who is a volcano expert (in addition to being a world-class amateur astronomer). He agreed to take a group of us out on the flows for a day. So, we prepped (lots of water, food, safe clothing, first-aid kit, did I mention water?) and met up with him for a lava jaunt.
It was amazing. There’s nothing that can prepare you for an encounter with fresh flowing lava, unless, by chance, you spend your life next to 1200-degree (F) ovens all day. Even then, you can step away from an oven. Lava, not so much.
In hiking across this flow we encountered many “breakouts” of lava, basically bubbling up and through rock that had been laid down perhaps a few hours up to a few days earlier. It was moving pretty slowly, so there was time to step out of the way, or even walk up to it and study its motion. As dangerous as it can be to encounter, lava is also a mesmerizing thing to watch. And, it is one of the few ways we can experience one of the main forces that shape our planet and have done so since Earth began to form around 4.5 billion years ago.
The lava flowing from this volcano is called basalt, and it comes from the melting of Earth’s mantle, deep beneath the crust on which we walk. It contains a number of minerals, all made up of elements that we can trace back to the elements that made up our planet during solar system formation. Where did those elements come from? Many came from the explosions of ancient supernovae (massive stars that die catastrophic deaths). So, in some sense, when we were looking at the lava that came flowing from Kilauea, we were looking at (as one our hiking companions said) the last gasp of the death of an ancient star. Taking it one step further, you could say that we were experiencing the latest episode in the formation of our own planet. Or, if you like, think of it as the ongoing effect of star formation, writ small on the surface of our own planet.
Want more info on the Kilauea volcano? Go here or here for lots of FAQ-type questions and answers about it.
