Toba Lake, in northern Sumatra, occupies the ancient Toba caldera. One of its outlets, the Asahan River, is the site of some spectacular white-water, a kayaker’s delight. For anyone willing to run the river, spare a thought for your early human ancestors, who it seems, were lucky to survive the aftermath of a cataclysmic super volcanic eruption 74,000 years ago. Be thankful that they did. Continue reading
Of the two certainties in life, volcanoes offer the most excitement (death and taxes are basically the same thing). They are magnificent while asleep; a primeval ruggedness that stirs the imagination. We paint them, we eulogise them. And when they awaken, we run for cover. Whether in a state of dormancy or high agitation, they leave an impression on our inner and outer landscapes.
All active volcanoes emit gas; pre-, during and post-eruption. On average, 96% of volcanic gases are water vapour, the remaining components being CO2, SO2 (most common), plus a little helium, nitrogen, carbon monoxide, hydrogen sulphide, and a few halides. Volcano-derived carbon dioxide is frequently cited as a culprit for increasing atmospheric CO2 concentrations in Continue reading