Mount Dana is a small stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 of the Alaska Peninsula

Alaska Peninsula

The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, 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

Pyroclastic flow

A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...

 that filled valleys south and west of the volcano's crater and reached the sea at Canoe Bay.

Geography and geology

Dana is northeast of the Canoe Bay inlet, as it sits at the top of Pavlof Bay. It is 555 miles (893 km) from Anchorage, the capital of Alaska.

The United States has the most active volcanoes in the world, many of them geologically young. In Alaska, at least 50 volcanoes, including those in the Aleutian archipelago, have erupted in historical time. The state accounts for ~80% of the United States' volcanoes, excluding the seamount

Seamount

A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of depth. They are defined by oceanographers as...

s 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

Pacific Ring of Fire

The Pacific Ring of Fire is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements...

, where tectonic activity generates earthquakes and volcanic eruptions in masses.

Made up of calcium and alkaline, the volcano hosts remnants of andesite

Andesite

Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

-based dome

Lava dome

|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...

, just off the western side of the crater and east of Knutson Lake. It resides on submarine sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 and shale

Shale

Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

, timed at the Jurassic and Cretaceous eras. Rising 1354 metres (4,442 ft), 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

Mesozoic

The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

 era stone.

Mount Dana is easily accessible from Canoe Bay, at any time of the year.

Eruptive history

While no recorded eruptions have taken place at the volcano, a flow of blocky lava and volcanic ash

Tephra

200px|thumb|right|Tephra horizons in south-central [[Iceland]]. The thick and light coloured layer at center of the photo is [[rhyolitic]] tephra from [[Hekla]]....

 is evident on the side of the volcano, streaming into Canoe Bay. Cold springs

Cold Springs

-Settlements:In Canada:*Cold Springs, Manitoulin District, OntarioIn the United States:*Cold Springs, El Dorado County, California*Cold Springs, Tuolumne County, California*Cold Springs, Indiana*Cold Springs, Nevada*Coldsprings Township, Michigan...

 and an enormous hill of tufa

Tufa

Tufa is a variety of limestone, formed by the precipitation of carbonate minerals from ambient temperature water bodies. Geothermally heated hot-springs sometimes produce similar carbonate deposits known as travertine...

at the volcano also suggest that Dana erupted previously.