While writing up my visit to Goat House Tube I was again wondering how old the lava tube was, it is clearly old, but how old?
Most of the Mauna Kea lava flows upon which Waikoloa sits are ten to twenty thousand years old, but the Mauna Loa flows that start just south of the village can be quite a bit younger.
Just a few miles south of the village one can find the 1859 Mauna Loa flow, the longest lava flow in the state representing a very long eruption that produced an enormous volume of lava. This is the flow that reshaped Kiholo bay, destroying the large fishponds that could once be found there.
In a folder of random reference material I had squirreled away there is a recent geologic map of the island, Geologic Map of the State of Hawaiʻi, Sherrod et al, USGS, 2021. Now just to compare this map with the satellite imagery from Google Earth to get it straight.
Good maps, but I was having trouble lining up the features on the ground. The complexity of the geologic map was making it difficult to see exactly what spot belonged to what lava flow.
Fine… Export both maps to image files, load them both into Photoshop, then overlay the geologic map right on the satellite image… Done. Now I can see just what goes where.
Interestingly the boundary between Mauna Kea flows and Mauna Loa flows is not where I thought it was. One of the older flows closer to Puʻuhinai, the flow in which Goat House Tube is situated, that I thought to be from Mauna Kea is actually Mauna Loa lava. While my memory was correct in that Puʻuhinai and the large flow that emanated from it is a Mauna Kea vent.
How old is Goat House Lava Tube? The answer is still the same I had before, something like ten to twenty thousand years old.
Share this:
