Our Travel Journal: Volcano, Big Island (Hawai'i Island), February 18, 2022

Hikes today were geological and archeological. Lava tubes are a natural and common happening in volcanic lava flows. They form as a channel of lava starts cooling from the edges, and these edges harden first. As the lava continues to flow through the channel with the now rock hard sides its 2,000 degree Fahrenheit molten rock starts melting the rock below, cutting the channel deeper and deeper. Eventually the lava flow will start moving slow enough that the top of the channel solidifies, which finally encloses the tube. The hot lava continues to flow until finally the source of the lava "dries up", the lava drains out and we are left with an empty lava tube with a flat floor. Today Sandy and I visited the Thurston Lava Tube on the southeast side of Kīlauea.

Down at the bottom of the mountain is a great lava field that was formed between AD 1200 and 1450. Shortly after the lava quit flowing and the rock solidified, ancient Hawai'ians came out upon them to etch their petroglyphs. These petroglyphs are etched into the lava and no coloring is applied. The vast majority of them are little more than a small hole the size of a quarter, drilled into the relatively soft lava rock. The ancient Hawai'ian mothers would drill that hole and then place a piece of a newborn's umbilical chord in the hole. This ritual was to assure the child a long life. To get to this field we need to hike for a mile and a half across the lava rocks with no shade. Fortunately the temperature was in the low seventies with gentle trade winds constantly fanning us. Seeing these markings in the lava rock, imagining those Hawai'ians patiently carving them out, helps one understand more, and feel closer to, the pre-contact, stone age culture that existed for so many years on this island.