Wednesday, October 22, 2008

Sunset Crater

North of Flagstaff, we visited Sunset Crater Volcano National Monument.

Sunset Crater was formed during volcanic eruptions between 1040 - 1100. The park service has put together a 1 mile trail through some interesting volcanic lava flows and cinder fields.

Parts of the trail involve picking your way along rocks and cinders, while other parts are paved.

This is sunset crater itself (at the top of the peak). Until the 1960's, park visitors were permitted to climb Sunset Crater. Now, climbing the crater is forbidden due to erosion.

You can still see two diagonal lines going up the side of the crater. Those lines are what remains of the old trail that was closed in the 1960's. Before it was filled in, the trail had eroded so that it was waist deep.

The orange cone in the photo below was once the top portion of an erupting volcano. Eventually, the eruption got so powerful that the whole top of the mountain flowed down the mountain, with the cone intact.

Hornitos are another volcanic feature. A hornito is a small opening that forms on the top of a flowing lava tube where lava bubbles up. In Spanish, hornito means "little oven".

Archaeologists sometimes find imprints of corn cobs near the hornitos in this area. That corn is believed to have been left as an offering.

The mountains in the distance are part of the San Fransisco Volcanic Field as well. The mountains just north of Flagstaff are all volcanic in origin. Their perfect conical shape is one telltale sign that they were once volcanoes.

This volcanic field formed as a tectonic plate moved across a hot spot below the earth's crust.

How did I become such a volcano expert? The park has signs and a trail guide so that visitors can understand what they're seeing.

In most natural areas, plants return to a devastated area in a fairly orderly process known as succession - where the plant species return in a particular order. Due to the dry climate and size of this volcanic field, plants return in a more random order here. Their seeds may be blown into the area or carried in via animal or bird droppings, so a unique order of succession occurs here.

The other volcanic fields we've visited, in Costa Rica and in Hawaii, were re-vegetating much more quickly due to the moister conditions.

Driving north away from Sunset Crater, we noticed the crater of another less famous volcano.

The eruptions in this volcanic field may have contributed to the Sinaguans abandoning this area in the 1400's.

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