Toba was a supervolcano that unleashed a catastrophic eruption some 74,000 years ago, ejecting millions of cubic miles of ash into the atmosphere, triggering a global winter that lasted for years. Ash from the Toba supervolcano has been detected as far as Africa, the continent least affected by the eruption.
Today’s Toba caldera was formed by the fusion of 4 volcanic craters, giving rise to a massive caldera 100km by 30km. After volcanic activity had died down, the extinct supervolcano began to collect water in the caldera, forming the Lake Toba that we know today.
Most people who visit Lake Toba would spend their time frolicking along the lakeside. Staying at upmarket lakeside resort means plenty of noisy water sports. I decided that the trip cannot be complete without a panoramic view for a full appreciation of the amazing forces of Mother Nature.
A new airport at Salangit is just 2 hours’ drive to Parapat – the main port for departures to Samosir Island. The east coast of the island is the main tourist area. The drive from Medan here takes about 5 hours. From the airport at Medan to Lake Toba, it may only take 4 hours.
On this trip, we approached Simalem on the northern aspect of the caldera overlooking Lake Toba. It’s thus inconvenient to approach from Silangit. We went through Berastagi to arrive at Simalem. From Simalem, it’s a long drive to Tuk Tuk on the east coast of Samosir. We returned to Medan from Lake Toba via the more conventional route.
In 2016, a study revealed that the Toba Supervolcano has a magma chamber containing 50,000 km2 of eruptible magma, about 30–50 km underground. The most recent eruption may have been at Tandukbenua on the northwestern caldera edge, suggested by a lack of vegetation that could be due to an eruption within the last few hundred years. Vulcanologists should be able to predict future major eruptions should Toba decides to come back to life.