Izu-Tobu Volcano | John Seach



Honshu, Japan

34.92 N, 139.12 E
summit elevation 1406 m
pyroclastic cones

Izu-Tobu Volcano is located in NE Izu peninsula, 80 km SW of Tokyo, Japan. 

The volcano is comprised of cinder cones, lava flows, lava domes, and pyroclastic flows, covering an area of 400 sq km. There are many submarine volcanoes located on the sea floor offshore of the peninsula.

Izu-Tobu volcanic group consists of the northern Omuroyama Group, and the southern Amagi Lateral Group. The volcano contains over 70 monogenetic cones. The volcano consists of bimodal volcanism; with a large volume of basaltic magma and a smaller amount of andesite.

Ito is the largest city situated within Izu-Tobe Volcano Group. The population is about 70,000. Many tourists are visiting hot springs and resorts in the city.

1998 Earthquake Swarm
A total of 10,800 earthquakes were detected during 20 April-12 May 1998 off the east coast of Izu Peninsula. Over 200 earthquakes were felt by nearby residents. The earthquakes were caused by shallow magmatic activity.

1997 Earthquake Swarm
On 3-12 March 1997 an earthquake swarm occurred close to Ito City on the eastern side of the Izu Peninsula. The total number of earthquakes recorded was 9,080, with 441 being felt.

1993 Earthquake Swarm
Between 28 May and 8 June 1993 a total of 9,500 earthquakes were recorded at Izu-Tobu Volcano. Hotels on Ito city lost business as 60,000 people canceled their holidays.

1989 Eruption
A submarine eruption occurred a few kilometers off the coast of the Izu Peninsula on 13th July 1989 after 2 weeks of earthquake swarms. The largest earthquake was 5.5 and 18 people were injured. The surface of the sea domed upwards 500 m from a research vessel RV Takuyo. Gray-black plumes rose 30 m high and activity ceased after 5 minutes. The eruption site was located between Ito City and Hatsushima Island, a distance of 10 km.

Izu-Tobu Volcano Eruptions

1989, 1930?, 1150 BC ± 50 yr, 2100 BC ± 100,