The Valley of Ten Thousand Smokes is a valley within Katmai National Park and Preserve in Alaska which is filled with ash flow from the eruption of Novarupta on June 6-June 8, 1912. Following the eruption there were thousands of fumaroles venting steam from the ash. Robert F. Griggs, who explored the volcano's aftermath for the National Geographic Society in 1916, gave the valley its name. Griggs wrote: "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." Katmai National Park and Preserve is a United States National Park in Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. ... Official language(s) English Capital Largest city Juneau Anchorage Area  Ranked 1st  - Total 663,267 sq. ... Novarupta, meaning new eruption, is a volcano located on the Alaska Peninsula in the Katmai area, about 290 miles southwest of Anchorage. ... June 6 is the 157th day of the year in the Gregorian calendar (158th in leap years), with 208 days remaining. ... June 8 is the 159th day of the year in the Gregorian Calendar (160th in leap years), with 206 days remaining. ... 1912 (MCMXII) was a leap year starting on Monday in the Gregorian calendar (or a leap year starting on Tuesday in the 13-day-slower Julian calendar). ... Sulfur deposits near a fumarole A fumarole (Latin fumus, smoke) is an opening in Earths (or any other astronomical bodys) crust, often in the neighborhood of volcanoes, which emit steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. ... Robert Fiske Griggs was a botanist who led a 1916 National Geographic Society expedition to observe the aftermath of the Katmai volcanic eruption. ... Flag of the National Geographic Society The National Geographic Society, which is based in the United States, is one of the worlds largest not-for-profit educational and scientific organizations, with a mission to advance the general knowledge of geography and the world among the general public. ...

The 1912 eruption was the largest (most voluminous) eruption in the 20th century (erupting about 13 cubic km of material). Novarupta generated as many as 14 major earthquakes, with magnitudes between M6 and M7 (release of this much energy is virtually unprecedented during volcanic eruptions), and over 100 earthquakes greater than M5. Following the eruption, the summit of Mount Katmai subsided (collapsed) about 1200 m, forming the central caldera. Crater Lake, Oregon A caldera is a volcanic feature formed by the collapse of a volcano into itself. ...

Katmai is a stratovolcano, being formed of alternating layers of lava flows and pyroclastic rocks. The mere presence of pyroclastic materials indicates that Katmai eruptions are explosive, as is further evidenced by the subsidence of the summit to form the central caldera and the extraordinarily energetic earthquakes accompanying the 1912 eruption. Pyroclastic rocks are formed from lavas which are ejected into the air, as occur in pyroclastic flows or Plinian eruptions. ... Pyroclastic rocks are formed from lavas which are ejected into the air, as occur in pyroclastic flows or Plinian eruptions. ... Crater Lake, Oregon A caldera is a volcanic feature formed by the collapse of a volcano into itself. ...

Canyon cut in ash by River Lethe

The ash filled valley covers a 40 square mile (104 km²) area and is up to 700 feet (210 m) deep. In places deep canyons have been cut by the River Lethe, allowing one to view the ash flow strata. Since the ash has cooled, most of the fumaroles are now extinct and the valley is no longer filled with smoke, but it retains its name. The signs of volcanic activity are still visible on nearby hills. Katmai's most recent eruption was 1927, but there have been non-eruptive events as recent as 2003. The Alaska Volcano Observatory still monitors Katmai's activity as part of the Katmai Cluster, where there are 5 active stratovolcanos within 15 km of Katmai. I took this photo of the River Lethe in the Valley of 10,000 smokes while backpacking there in August, 1986. ... I took this photo of the River Lethe in the Valley of 10,000 smokes while backpacking there in August, 1986. ... Canyon cut in ash by River Lethe River Lethe is located 18 km (12 mi) west of Mount Katmai, Alaska Peninsula, and is the middle branch of Ukak River. ...

External links

• Alaska Volcano Observatory page on Katmai
• Maps of region