Toba Volcano | John Seach


Sumatra, Indonesia

2.58 N, 98.83 E
summit elevation 2157 m

Toba Volcano is located in Northern Sumatra, 80 km south of Medan. Lake Toba is 85 x 30 km in size and is the earth's largest caldera formed in the past 1.8 million years.

The eruption of Toba in 72 000 BC was one of the largest in the last few hundred thousand years, with 2800 cubic km of magma being erupted. Particles from the Toba eruption remained in the air for 6 years and world temperatures were reduced by 5 to 10 deg C. A small fumarole field is located at the southern tip of Samosir Island.

Toba has been called a supervolcano due to its large magnitude eruption.

2022 Earthquake
A magnitude 5.1 earthquake occurred under Lake Toba on 06 March 2022. The focus was at a depth of 155 km, and epicentre 9 km east of Parapat.

2021 Earthquake
A magnitude 4.9 earthquake occurred under Lake Toba on 27 March 2021. The focus was at a depth of 148 km, and epicentre on the southern end of Samosir Island in the lake.

Further reading
Chesner, C.A., 2012. The Toba caldera complex. Quaternary International258, pp.5-18.

Rose, W.I. and Chesner, C.A., 1990. Worldwide dispersal of ash and gases from earth's largest known eruption: Toba, Sumatra, 75 ka. Global and Planetary Change3(3), pp.269-275.

Aldiss, D.T. and Ghazali, S.A., 1984. The regional geology and evolution of the Toba volcano-tectonic depression, Indonesia. Journal of the Geological Society141(3), pp.487-500.

Toba Volcano Eruptions

74,000 years ago.

The most recent eruptions may have occurred at Pusukbukit in the south of the caldera and Tandukbenua on the NW caldera rim.