Driving back to our hotel from Hilo took us across the center of Big Island. This is a pretty high drive as you pass between the two big mountains of Mauna Kea and Mauna Loa. Mauna Kea is the home to a number of observatories. We did drive some way up the mountain to the visitor’s center. You are already at quite some altitude at this point and you could feel the lack of air when you moved too quickly. There was an option to drive all the way to the top but we had other things scheduled and didn’t make the trek up.
From the visitor center, you couldn’t actually see the observatories. However, as we drove towards the turn for the mountain, we did come to a pull off where you could see them up on the summit with the sun glinting off the domes of the larger installations. Another time I would certainly like to go all the way to the top. However, I think I shall be alone on that trip as Nancy was already feeling the effects of the altitude.
The active volcanoes are cool to see but the landscape on the Big Island is dotted with plenty examples of where the earth has had a previous effort at disgorging its contents. The mountains of Mauna Loa and Mauna Kea look exactly like you would expect a volcano to look with a nice big flat conical structure. However, the eruptions have not all come from the top of the mountain. There have been regular eruptions from weak points along the surface of the mountains and these eruptions have left their mark in more ways than just the lava flows scarring the slopes below them.
When the lava breaks out, it hardens as it reaches the surface. The deposits around the opening grow and you create a mini version of the mountain. These are called cinder cones. They are scattered all around the landscape and each was the site of a previous eruption. The center is hollow where the lava flowed out and sometimes the weakest side may have collapsed to leave the cone a little more exposed. The color of the rock can be pretty dramatic too. They look so benign now but at their most active peak, these places would have been spewing forth huge quantities of red hot molten rock. They would not have been a good place to be.