At the park, we took in the displays and a movie at the visitor center.  I then told everyone to cross the road to Volcano House, where they got their first view of Kilauea Caldera.  Kilauea is always impressive with Mauna Loa soaring above it to the NW.  I bought some tee shirts and a Humuhumunukunukuapua’a hat at the gift shop.
 
 

From Volcano House, there is a good view of the northwest wall of Kilauea Caldera. It is a high cliff that displays numerous lava flows similar to those that cover the caldera floor. Mauna Loa looms almost 9,000' higher in the background.

Next, we drove to the Hawai'i Volcano Observatory and took in the excellent displays at the museum.  We also stopped at the Sulfur Banks Fumarole.  Then, we drove to the Halemaumau overlook parking lot and had lunch before walking out to the crater.  A group of Japanese tourists were conducting a Shinto (?) ceremony at the crater’s edge.  We got on the Chain of Craters Road and started heading down to the coast, stopping to examine the pahoehoe and aa flows at the top of the Holei Pali.  We also stopped to photograph to the west along the coast and the various fault scarps and benches.
 

Halemaumau crater sits within Kilauea caldera. Because of all of the  activity in this portion of the caldera, the caldera wall was breached many  times. It can barely be seen as a thin, black line behind the crater. This photo was taken from the Hawai'i Volcanoes Observatory.

This panoramic view shows the scale of the caldera relative to Halemaumau crater.

The view from the edge of Halemaumau Crater within Kilauea Caldera is  rather Dantean. Fumaroles exude steam and volcanic gas. The smell of hydrogen sulfide and taste of sulfur dioxide occasionally waft through the overlook. During most of the 1800's a lava lake occupied the crater. It occasionaly overflowed its banks and spilled out onto the caldera floor.

Lava flows cascaded over the Holei Pali. Both aa and pahoehoe lava can be seen in this image. Aa is the dark, rough, sharp, clinkery material seen in the foreground. The pahoehoe is much glassier and reflective giving it a lighter appearence. It exhibits a characteristic ropey texture. The two lavas are the same composition and are from the same event. The amount of water dissolved in the lava decreases, thereby increasing the viscosity during the transition from pahoehoe to aa. Note the shoreline far below in the upper left.

We arrived at the end of the road under clear sky and a hot sun.  A female ranger at the visitor center had given directions on how to get to the activity at the nose of the flow.  I could see the landmarks she mentioned and we headed for them.  The hike across the Pahoehoe was beautiful in its textures and structures but difficult and monotonous.  There was no smooth ground.  Everything was either up a few feet or down a few feet.  The footing was irregular and often slippery.  A few students fell and cut their legs. Shelley was the first but Liz achieved the worst cuts.

A ranger caught up with us and redirected us to a different landmark.  It was well beyond the second kipuka that we had been heading toward. About an hour later, I realized he was wrong and the woman at the Visitor’s Center had to be right.  We could see the steam rising off the flow just west of the second kipuka.  Oliver and Jana caught up with us to warn us of the ranger’s error and then ran ahead to redirect those who had outpaced the others.  Elise, Shelley, and I headed toward the flow at the base of the Pali and were soon rewarded with our first view of red rock.  We called the others who were re-energized by the news.

We were able to get within several feet of the slowly moving flow.  Heath threw rocks into the molten rock.  Most were surprised to see how viscous and dense it is.  Nick tossed his nalgene bottle onto it (with a tether) to give it an interesting battle scar.  I’m sure he’ll have stories to tell.  Annie tethered a cigarette and used the flow as a cigarette lighter.  Ahh, student ingenuity.
 

Glowing pahoehoe lava oozes from beneath the thin, black crust of recently molten rock. Although it is a liquid, the viscosity is so hugh that rocks float on top of the molten material. Heath and Troy threw rocks into the red rock but not a single droplet spattered upon impact. Instead, the slightly denser black rock slowly sank into the red rock.

This photo was taken about 10 minutes after the one above on the same part of the flow. Note how a crust has formed over much of the red area seen in the previous image. The classic ropy texture with which pahoehoe is associated can be seen forming on the new crust.    See more photos

We stayed at the site for about 40 minutes and then started the hike back.  My left big toe split and gave me a lot of pain.  After 45 minutes we needed our headlamps.  The hike became a drag really quickly but was mitigated by the incredible glow from the lava flow at the top of the Pali.  I sent the fastest hikers ahead to turn on the car lights so we could have the end in sight.  That reduced the grumblings of those who wanted everyone to hike together.

I don’t think paved road ever looked so good to me as when we returned to the ranger station.  I felt like this 49-year old cripple that I am.  This was another one of those days when I wondered why I like doing this stuff so much.  It took us 7 ½ hours for this excursion.  It was well worth it but everyone was beat.

We drove back up the Pali and back to the highway.  I was very tired as we descended the 30 miles back into Hilo.  Pizza Hut was closed so we went to the Taco Bell drive-thru.  Heath managed to convince the guy that the third vehicle would pay for the first two as well.  We returned to the hotel and ate and showered.  Partying was kept to a minimum, everyone was too beat.  I fell asleep as soon as my head hit the pillow.