1998 Caltech GPS Student Expedition to

Katmai National Park, Alaska

A fossil fumarole colors the floor of the Valley of Ten Thousand Smokes.

When Novarupta erupted in June of 1912, it filled the Valley of Ten Thousand Smokes with hot ash. This ash covered rivers and melted snow and glaciers. The rivers and melt water interacted with the hot eruptive deposits and formed hydrothermal systems. These hydrothermal systems created numerous fumaroles, or steam vents, which were still active when the Griggs expedition arrived in the Valley in 1918, in search of the 1912 eruptive vent. It is these fumaroles that lent the Valley its name. All that is left of most of these fumaroles are joint systems and colorful mineral deposits left behind by the hot circulating water.

The Knife Creek cuts its way through the deposits of the Novarupta eruption on its way through the Valley of Ten Thousand Smokes.

At the edge of the Valley, the ash fall aggraded against a glacier, melting it and damming it at the same time. This ash dam ponded a series of lakes, known as the Mageik Lakes, in the west branch of the Valley of Ten Thousand Smokes. These lakes are the headwaters of the River Lethe, which cuts a pencil thin gorge through the ash fall as it flows down the Valley. The speed at which this gorge was cut is unknown, but the majority of its 100 foot depth had already been eroded 4 years after the eruption when the Griggs expedition surveyed the area.




Mageik Lakes in the shadow of Mt. Mageik at the head of the Valley of Ten Thousand Smokes.

The Katmai National Park area is unique along the length of the Aleutians for the density of active volcanos. Five active volcanos, Mt. Griggs, Mt. Katmai, Mt. Trident, Mt. Mageik, and Mt. Martin, are all visible from the Valley of Ten Thousand Smokes. Steam often rises from the peaks of some of these volcanos, testament to their active state.

Steam escapes the top of Mt. Mageik as seen from Katmai Pass.