Mount Dana (Alaska)
{{Short description|Small stratovolcano in Alaska, United States}}
{{Infobox mountain
| name = Mount Dana
| photo = Mount Dana volcano.jpg
| photo_caption = Crater of Mount Dana
| map = Alaska
| map_caption = Location in Alaska
| mapframe = yes
| mapframe-zoom = 8
| mapframe-caption = Interactive map of Mount Dana
| elevation_m = 1354
| elevation_ref =
| prominence =
| listing = List of volcanoes in the United States
| location = Alaska Peninsula, United States
| range =
| coordinates = {{coord|55.641|N|161.214|W|type:mountain_region:US-AK|display=inline,title}}
| topo =
| type = Stratovolcano
| age =
| volcanic_arc = Aleutian Arc
| last_eruption = 1890 BCE (?)
| first_ascent =
| easiest_route =
}}
Mount Dana is a small stratovolcano of the Alaska Peninsula, United States, located northeast of Canoe Bay inlet at the head of Pavlof Bay. It was the source for a major eruption about 3840 years ago that produced a pyroclastic flow that filled valleys south and west of the volcano's crater and reached the sea at Canoe Bay.{{cite gvp|vn=312050|name=Dana}}
Geography and geology
Dana is northeast of the Canoe Bay inlet, as it sits at the top of Pavlof Bay. It is {{convert|555|mi|km|0}} from Anchorage.{{cite web|url=http://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Dana|title=Dana description and statistics|publisher=United States Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS)|accessdate=November 21, 2009}}
The United States has the most active volcanoes in the world, many of them geologically young.{{cite web|url=http://pubs.usgs.gov/fs/2006/3142|title=The National Volcano Early Warning System (NVEWS): U.S. Geological Survey Fact Sheet FS 2006-3142|publisher=United States Geological Survey|author1=Ewert, John|author2=Guffanti, Marianne|author3=Cervelli, Peter|author4=Quick, James|year=2006|accessdate=July 9, 2009}} In Alaska, at least 50 volcanoes, including those in the Aleutian archipelago, have erupted in historical time.{{cite journal|url=http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=16061|title=Alaska GeoSurvey News: NL 2008-1|publisher=Alaska Division of Geological & Geophysical Surveys|date=March 2008|accessdate=July 9, 2009|volume=11|issue=1|pages=1–14}} The state accounts for ~80% of the United States' volcanoes, excluding the seamounts in the area, ~8% of world volcanoes, and most of these are located among the Aleutian Islands. The Aleutian Islands arc serves as the northern boundary of the Pacific Ring of Fire, where tectonic activity generates earthquakes and volcanic eruptions in masses.
Made up of intermediate composition calc-alkaline rocks, the volcano hosts remnants of an andesite-based dome, just off the western side of the crater and east of Knutson Lake. It resides on submarine sandstone and shale, timed at the Jurassic and Cretaceous eras.Kienle and Wood, p. 54. Rising {{convert|1354|m|ft|0}}, the volcano is topped by a crater 1.5 kilometers in height by 2 kilometers in width. To the southwest of the caldera, an exposed sector reveals a layer of sedimentary Mesozoic era stone.
Mount Dana is easily accessible from Canoe Bay, at any time of the year.Kienle and Wood, p. 55.
= Eruptive history =
While no recorded eruptions have taken place at the volcano, a flow of blocky lava and volcanic ash is evident on the side of the volcano, streaming into Canoe Bay. Cold springs and an enormous hill of tufa at the volcano also suggest that Dana erupted previously.