Friday, Nov 21, 2008
On 17 November the alert level for Akan volcano was rised to level 3. There have been recorded tremors and a cloud that was the result of an ash eruption that covered the crater rim with black ash. Also ballsitic lithics were deposed around the crater. [more]
Thursday, Oct 23, 2008
On 17 October, JMA lowered the Alert level for Me-Akan (also called ... [more]
Akan volcanoAkan volcano (阿寒岳, Akan-dake) is one of Hokkaido's most active volcanoes. Akan consists of a large 24 x 13 km diameter caldera and a group of younger partly Holocene andesite cones. The highest point of the complex is the Mount Meakan (1499 m) stratovolcano.
The frequent historic eruptions occurred all from the Me-Akan group, east of Lake Akan. Me-Akan volcano (雌阿寒岳 Meakan-dake) consists of 9 overlapping cones. Its summit has 3 craters.
Me-Akan has had at least 17 small phreatic eruptions since the beginning of the 19th century and from geologic studies it is known that there were at least 4 major magmatic eruptions with pyroclastic flows have occurred in prehistoric time during the past 10,000 years.
Lake Akan is part of the Akan National Park. It is known for a rare green algae (marimo) which can grow to about the size of a soccer ball. The only town around the lake is the resort of Akankohan known for its hot springs and the "bokke", bubbling mud pools found at the lakeshore.
Background:The Akan caldera is located immediately SW of Kutcharo caldera and has an elonogated, irregular shape due to several caldera-forming explosive eruptions between the early and mid Pleistocene.
Growth of 3 post-caldera stratovolcanoes, 3 at the SW end of the caldera and the other at the NE side, has reduced the size of the caldera lake. The conical O-Akan volcano was frequently active during the Holocene. The 1-km-wide Nakamachineshiri crater of Me-Akan volcano was formed during a major pumice-and-scoria eruption about 13,500 years ago.
Tremor was recorded on 17 November 2008. A small ash eruption occurred on 18 November, and was later detected by a fresh deposit of ash on snow in up to 400 m distance from the Ponmachineshiri crater. Another ash eruption occurred on 28 November, producing a small ash plume reaching 2 km altitude.
(Source: Smithsonian / GVP monthly reports)
A small eruption occurred from a vent on the NE flank of Meakan on 21 March 2006. Ashfall was observed 10 km SE of the volcano.
A small ash eruption occurred from Meakan volcano on 9 November 1998.
A small phreatic eruption occurred on 21 November 1996.