is an active 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 Kameda peninsula. It is located in Hakodate

Hakodate, Hokkaido

is a city and port located in Oshima Subprefecture, Hokkaido, Japan. It is the capital city of Oshima Subprefecture.Hakodate was Japan's first city whose port was opened to foreign trade in 1854 as a result of Convention of Kanagawa, and used to be the most important port in northern Japan...

, Hokkaidō

Hokkaido

, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

, Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. Mount E is part of Esan Prefectural Natural Park

Esan Prefectural Natural Park

is a prefectural natural park of Hokkaidō, Japan. The park encompasses of the Kameda Peninsula of the Oshima Peninsula. The park was founded in 1961. There are four main areas of the park: Mount E, the coastal area, the forested area, and Mount Yokotsu....

.

Geology

Mount E consists of non-alkali

Alkali

In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...

, mafic

Mafic

Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron; the term is a portmanteau of the words "magnesium" and "ferric". Most mafic minerals are dark in color and the relative density is greater than 3. Common rock-forming mafic minerals include olivine,...

, volcanic rock

Volcanic rock

Volcanic rock is a rock formed from magma erupted from a volcano. In other words, it is an igneous rock of volcanic origin...

. The andesitic volcano is topped with a lava 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...

.

Eruptive history

Mount E last erupted on June 8, 1874. This eruption consisted of phreatic explosions and was rated a 1 on the VEI scale.

The oldest recorded eruption started November 18, 1846. The eruption triggered lahar

Lahar

A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...

s damaging several houses and causing fatalities.

Radiocarbon dating

Radiocarbon dating

Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...

 and tephrochronology

Tephrochronology

250px|thumb|right|Tephra horizons in south-central [[Iceland]]. The thick and light coloured layer at the height of the [[volcanologists]] hands is [[rhyolitic]] [[tephra]] from [[Hekla]]....

indicate five other eruptions predating the historical records in the approximate years 1350, 550 BC, 1050 BC, 3900 BC ±100 years, 7050 BC. The eruption in 7050 BC was the largest with a VEI of 3.