Esan Volcano & Esan-Maruyama Volcano, SRTM-1

is an active

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

of the Kameda peninsula, which is itself part of the larger

Oshima Peninsula The Oshima Peninsula (渡島半島 ''Oshima-hantō'') is the southernmost part of Hokkaidō, the northernmost of the Japanese islands. Where the peninsula starts is open to interpretation. A more generous interpretation is to draw a line southea ...

. It is in the rural, eastern region of

Hakodate is a city and port located in Oshima Subprefecture, Hokkaido, Japan. It is the capital city of Oshima Subprefecture. As of July 31, 2011, the city has an estimated population of 279,851 with 143,221 households, and a population density of 412.8 ...

Hokkaido is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; th ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

. Mount E is part of Esan Prefectural Natural Park.

Geology

Mount E consists of non-alkali,

mafic A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks in ...

volcanic rock Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic ...

. The

andesitic Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomin ...

volcano is topped with a

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions ...

Eruptive history

Mount E last erupted on June 8, 1874. This eruption consisted of

phreatic explosion A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evap ...

s, and was rated a 1 on the VEI scale. The oldest recorded eruption started November 18, 1846. The eruption triggered

lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent 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. Lahars are extr ...

s damaging several houses and causing fatalities.

Radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...

and

tephrochronology 250px, Tephra horizons in south-central Iceland. The thick and light coloured layer at the height of the volcanologist's hands is rhyolitic tephra from Hekla. Tephrochronology is a Geochronology, geochronological technique that uses discrete l ...

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.

References

External links

Esan
- Japan Meteorological Agency * - Japan Meteorological Agency

- Geological Survey of Japan
Esan: Global Volcanism Program
- Smithsonian Institution Stratovolcanoes of Japan Volcanoes of Hokkaido Mountains of Hokkaido {{Hokkaido-geo-stub