From there, we drove to the Thurston Lava Tube and walked through it.  Everyone loved it.  Most also did the unimproved extension.  I didn’t because my headlamp had died the night before.  We ate lunch in the parking lot.  Jana, Troy, Spring, and Sara played Hackey Sack. 
 

The Thurston lava tube is a superb example of this relatively common feature. A fluid lava flowed down a slope. Its outer surfaces cooled while the interior continued flowing. At the end of the eruptive episode, the fluid lava drained out of the tube and left a tunnel. Although the rock is black, its glassy surface reflects the light from the flask very well. For scale, Elise is 5' 9" tall.

Our next stop was at Pu’u Pu’ai overlook and then to the devastation trail.  I was impressed by the change in the devastation area since I last hiked it in 1983.  The Ohia forest has reclaimed most of the area but Pu’u Pu’ai is still barren due to the high porosity of the cinder.

We then proceeded to the Kilauea Iki overlook and hiked the rim trail back to the crater.  Elise and Annie discovered that they had been dating the same guy at the same time on the way down.  They began to plot revenge.

We walked out onto the crater floor, which is still steaming from the 1959 eruption.  The lava lake is about 400 thick.  Walking on a Pahoehoe lava lake is much easier than Pahoehoe flows.  I set up a 175m baseline on the trail and had the students triangulate points on both sides so that they can determine the crater width.  We then walked over to the L959 vent and recapped the events of that eruption, including the 1900’ lava fountain.  At 5:00, I called it a day and we hiked back out of the 400’ deep crater to the vehicles and drove back to the Hilo.
 
 

The lava lake in Kilauea Iki crater is still molten  deep beneath the surface. Steam fumaroles can  be seen on the crater floor (white). Pu'u Pu'ai is  the hill at the back of the crater on the left. The  main Kilauea caldera is visible in the background.

Brevard students begin their hike across the lava lake at the bottom of Kilauea Iki crater. Note how smooth the pahoehoe floor is compared to the lava flows seen on the previous day. The cracks in the floor formed as the lava cooled and contracted.

The flat terrace in the center of the photo can be traced all around the  perimeter of Kilauea Iki. It represents the level that the lava lake attained at  the end of the 1959 eruption. As the molten rock has cooled since then, its volume has contracted and most of the lake has subsided. At the deepest part, the lake is more than 400 feet deep. Numeroussteam vents attest to  higher temperatures down below.

Although all of the compases make it appear that the students are lost, they are actually attempting to determine the width of Kilauea Iki crater by triangulating predetermined points from both ends of a baseline. The results were varied but most agreed that it was a worthwhile exercise. It sure beats measuring it with a ruler!

Beth got us reservations at the Nihon restaurant at the Japanese Cultural center.  It was excellent.  Most people really enjoyed their food but there was the requisite amount of grumbling from some quarters. Group behaviour is so predictable!

We returned to the hotel and had a social hour, mostly on our Lanai.  Joan called at 10:30 and we talked for nearly an hour.  It was great to hear her voice.  I then went to bed and fell asleep almost immediately.