- Valley of Ten Thousand Smokes
The Valley of Ten Thousand Smokes is a
valleywithin Katmai National Park and Preservein Alaskawhich is filled with ash flow from the eruption of Novaruptaon June 6—June 8, 1912. Following the eruption, thousands of fumaroles vented steamfrom the ash. Robert F. Griggs, who explored the volcano's aftermath for the National Geographic Societyin 1916, gave the valley its name, saying that "the whole valley as far as the eye could reach was full of hundreds, no thousands—literally, tens of thousands—of smokes curling up from its fissured floor."
The 1912 eruption was the largest eruption by
volumein the 20th century, erupting about convert|13|km3|cumi|sigfig=2|sp=us of material. Novarupta generated as many as 14 major earthquakeswith magnitudes between M6 and M7, a level of energyrelease virtually unprecedented during volcanic eruptions in modern memory, and over 100 earthquakes greater than M5. Following the eruption, the summit of Mount Katmaisubsided (collapsed) about convert|1200|m|ft|sigfig=2|sp=us, forming the central caldera.
Katmai is a
stratovolcano, formed from alternating layers of lava flows and pyroclasticrocks. The presence of pyroclastic materials indicates that some Katmai eruptions have been explosive. The subsidence of the summit to form the central calderaand the extraordinarily energetic earthquakes accompanying the 1912 eruption are evidence of this.
The ash-filled valley covers a convert|40|sqmi|km2|sigfig=2|adj=on area and is up to convert|700|ft|m|sigfig=2 deep. In places deep canyons have been cut by the
River Lethe, allowing observers to see the ash flow strata. Since the ash has cooled, most of the fumaroles are now extinct and despite its name the valley is no longer filled with smoke. The signs of volcanic activity are still visible on nearby hills. Katmai's most recent eruption was in 1927, but there have been non-eruptive events as recent as 2003. The Alaska Volcano Observatorystill monitors Katmai's activity as part of the Katmai Cluster, where there are 5 active stratovolcanos within convert|15|km|mi|0|sp=us of Katmai.
Visitors to the valley most commonly arrive via bus along the convert|20|mi|km|0|adj=on road from
Brooks Camp, which is the only road in Katmai Park.
* [http://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Katmai Alaska Volcano Observatory page on Katmai]
* [http://pubs.usgs.gov/imap/i2778/ Maps of region]
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