Tuesday, June 15, 2010

Craters of the Moon National Monument

We are in a beautiful state, Idaho, and today we visited Craters of the Moon National Monument. Beginning millions of years ago, volcanic eruptions changed this landscape forever. The most recent eruption was 2,000 years ago. The first picture, above, shows a cinder cone. Cinders are spewed from a vent during an eruption of lava with high gas content.

Here is a view down the cinder cone into the eerie landscape.

We also saw spatter cones, which are mini-volcanoes which spit out chunks of cooling lava. Both of these features were formed by the Great Rift, a series of long fissures in the Snake River Plain. You can see the inside of a spatter cone in the picture below.

In the picture below, my child is hiking towards some lava tubes.

A lava tube is made when a crust forms over the top of a lava flow as it cools. Hot lava continues to flow underneath the crust. Eventually every tube will collapse.

When a tube shatters into small rocks as shown in the picture below, the lava has cooled quite a bit. If a tube collapses when the rock is still warm, it falls like a souffle, with a "whump" as I told my son, and it looks more smooth.

We use Hawaiian words to describe different types of lava. A-a, (my hyphen) is sharp, crusty rubble. Smoothly flowing, fluid lava is called pahoehoe.

I took many pictures of the strange forms of the lava flows.

The bubbles you sometimes see in lava rocks are formed by gases which emerge with the violent and explosive beginnings of a volcanic eruption.

Here is an entrance into a lava tube below. The sign says "Wild Cave" and is full of warnings about the dangers of exploring the lava tubes.

Exploring them is allowed, but you need to take great care! Try to wear something to protect your head from sharp rocks on the ceiling, watch your step as you descend over loose rocks, and carry a flashlight. It is pitch dark inside! There is ice inside some of the caves all year round and the ceilings are dripping. Some animals live inside. We saw pigeons! But there are other animals, too, including the Lava Tube beetle.

This rock below was in the entrance to one of the caves. I think many people had touched this bubble and polished it very smooth with their fingers.

The ceiling of this lava tube below is about 40 feet high. The pile of rubble you see behind the people is from a collapsed ceiling. One of the tubes in the park is 18 miles long.

These little rings of rocks were made by the Shoshone Indians, and may have been used for ceremonies. The Shoshone used the lava tubes for water and shelter as they crossed the landscape during their yearly migrations from the Snake River to the Camas Prairie.

Limber pines cling to the rocky landscape. They are the first trees to colonize the lava covered terrain. I was very amazed to see the number of wild flowers blooming in this inhospitable place. I wish we could have seen a kipuka. A kipuka is an island of green which has been created by lava flows. Kipukas in the park are preserves of the original natural sagebrush steppe.

These ants had created a hill out of twigs which was about 10 inches high. We kept our distance. Some American ants sting.

If you want to learn about how nature returns to an area devastated by a volcanic eruption, go to PBS.org and watch the Nova program about Mt. St. Helen's.

If you want to learn about an active volcano, Nova also has a program about Kilauea, a live volcano in Hawaii.

Next I will show you some of the amazing wildflowers which we saw growing up through the cinders and lava.


gardenmama said...

wow beth, what an incredible visit!
and this is in idaho?
your photo of the rock with holes in it, i have seen many large stretches of rock like this at the ocean.
what an interesting post, thank you for sharing it!

softearthart said...

WOW> What a cool place, cheers Marie

Nadja Magdalena said...

Never heard of this place! Thanks for the great photo essay!


looks like an amazing place! Love the photos.

Appleshoe said...

Hi Beth- this looks like it would be a fun place to visit. So much to see and learn. Take care.

Grace said...

What an amazingly cool place (that I've never even heard of... how could that be?) Enjoy your trip.