Almost everyone has heard of the Toba super-eruption, which took place on the island of Sumatra roughly 74,000 years ago, but the only evidence of tephra or tuff (volcanic fragments) from the eruption is in Asia, with nothing definite further afield. It has sometimes been thought that this huge eruption may have led to a volcanic winter, a period of at least several years of low temperatures follo ...[Read More]
Geosciences Column: From the desolate to the diverse, a story of volcanic succession
When a volcano erupts and spews lava onto the surrounding terrain, it is merciless in its destruction. All that is green on the land is engulfed in flame, or buried by an insurmountable mass of molten rock. Whatever charred remains of what lies beneath it will not see the light of day once the lava cools, turning the landscape into a barren black mass of solid basalt. But volcanoes around the worl ...[Read More]
Imaggeo on Mondays: Turkey’s cotton castle
This week, Imaggeo on Mondays is brought to you by Josep Ubalde, who transports us to a wonderful site in western Turkey: a city of hot springs and ancient ruins dubbed cotton castle, after the voluminous white rocks that spread from the spring’s centre… Pamukkale is lies in Turkey’s inner Aegean region, within an active fault that favours the formation of hot springs. The spring’s hot water ...[Read More]
Imaggeo on Mondays: Quartz lawns and crystal flowers
Petrologists spend a large part of their time peering down microscopes at wafer thin slices of rock to work out what they’re made of and how they were formed. What lies on the other side of the lens can be an incredibly beautiful pattern, a kaleidoscope of colour, or stark bands of black and white, all of which provide clues to the rock’s history, and the history of the landscape it came from. Ber ...[Read More]