Friday, June 5, 2009
The Return of the Airliner Chronicles: When the Giants Begin to Die
Another overflight of a major volcano, taken while we made our way to the Big Island of Hawai'i. Haleakala, on the Hawaiian island of Maui, is the third truly gigantic shield volcano in the island chain. At 10,023 feet, it is shorter than the giants on the Big Island, but it once stood thousands of feet higher. The sheer weight of the volcano depressed the ocean crust by thousands of feet, and the summit may have once hosted glaciers during the ice ages. But no more, for Haleakala is a volcano in its death throes. The mountain has moved off of the Hawaiian hot spot, and the rate and volume of its eruptions is greatly diminished. It may have erupted around 1790, but this date is suspect, and the most recent lava flow may date back to the 1400's.
We will visit the volcano in about a week, and I will have more to say about it. Visible in today's picture is the summit area, with two parking lots and "Science City", a cluster of observatories. A group of distinctive cinder cones and lava flows are visible in the top half of the photo, apparently filling a caldera, but as we will find in a future post, this is not actually the case.
Student in our geology field studies class began arriving in Hilo last night, and the rest arrive today, so we are almost ready to roll! Hard to say if blogging will be consistent this week, since I am teaching this class for the first time. I may neeed to spend evenings boning up on details so I can sound smart when I talk to the class...