Hot Lava and Cold Caves

Hi Blog.  We woke up bright and early on Tuesday, August 20, 2013, and got ready to hit the trail.  On our agenda were several different day hikes that would give us samples of all the different types of lava, as well as a chance to explore some caves formed by lava tubes.

As we hiked out the Tree Molds Trail, we walked right next to a pahoehoe flow now frozen in place. As the flow slows and cools, it folds up onto itself, just like an area rug on a hardwood floor.

The trail took us past several large cinder cones.  The loose gravel cinders went on for miles and miles. Because cinders are so light and airy, it feels a lot like walking on sand only with a loud crunch, crunch, crunch sound with each step.

There were several tree molds at the end of the trail, but they were not nearly as impressive as the lava trees we discovered on the Wilderness Trail.  The slow moving lava would hit a tree and then pile up and around it.  The tree would eventually burn away, but by that time, the lava had cooled around it leaving a mold of the trunk and lower branches.

You can even see impressions that the bark left in the lava.  Some of the lava trees were several feet high. The red squirrels in the area love to store their pine cones inside these molds.  Makes them easier to find in the winter.

We then took a self-guided loop hike around Broken Top, an old cinder cone that, you guessed it, lost its top. The side wall of the crater just broke away and floated down on a stream of hot lava.  As we followed our guide book, we learned all about the Great Rift (a 53 mile crack in the Earth's crust), the Blue Dragon (a lava flow that contains a thin layer of glass that refracts light and whose titanium composition makes the lava look blue), lava bombs (giant round blobs of lava that are shot out of the cone), spindles (same as lava bombs but due to how they deform in the air, they have bizarre spiral and other twisted shapes) and Kathy's personal favorite - lava toes.  Lava toes form at the edges of a flow where the last of the hot lava oozes out.  Here's Kathy comparing her toes to the lava toes:

The Great Rift is a giant nursery for volcanos.  All along the rift, cone after cone develops.  Some are cinder cones, spewing liquid lava up in the air that cools on its way down.  The cinders are so light that the wind can blow them making one side of the cone much higher than the other.  Spatter cones spew out much thicker lava in much larger chunks.

After lunch, we joined a ranger-led tour of the Caves Area.  As the lava flowed, the surface cooled faster than the hot lava stream underneath, creating vast networks of lava tubes once all the lava flowed out.  Sometimes the tubes collapsed while the roof of the tube was still warm creating craters on the surface of the lava field.  Other tubes cooled and parts of the ceiling crumbled in leaving openings into the tubes.  These were the openings we climbed into to explore the network of tubes.  Here is Kathy heading toward the light!

Here is a photo Kathy took of Dave standing at the bottom of Indian Tunnel, one of the largest caves open to the public.  There are over 350 known caves in the park.  However, the number could go much higher, since a ground penetrating radar survey shows thousand of tubes.  After the ranger left us, we were free to explore some of the other caves.

We stopped at Boy Scout Cave, so named because you had to be as small as a boy scout to squeeze through the opening.  We got part of the way in, but decided not to go further since it was a really tight fit and our headlamps were just not bright enough to penetrate the absolute darkness.  However, we did linger inside the cave opening for a little while since it was about 50 degrees and a very welcome respite from the hot desert sun.

The last cave we explored was Beauty Cave.  The opening here was much larger than Boy Scout, allowing more light in and giving us a chance to walk around without hitting our heads on the ceiling.  Again, this cave was so cold we could see our breath!  This cave had some water dripping from the ceiling and Kathy received her first "cave kiss." We knew it was time to leave the cave once we started shivering from the cold.

After the caves, we headed back to camp for a little happy hour and camp TV.  We did manage to stay awake long enough to enjoy the ranger program that evening. Tomorrow, we have a couple small nature trails to check out before our drive back to Pocatello.