A Supervolcano Sleeps Beneath The Wash
Beneath some of England's flattest farmland, scientists have found a 454-million-year-old supervolcano — and linked it to an ash layer spread across Scandinavia.
The Location
Under The Wash, the shallow bay on England's east coast between Lincolnshire and Norfolk, the landscape is about as dramatic as a puddle. Yet 454 million years ago this was the site of one of the largest eruptions in Earth's history — a hidden supervolcano now buried deep below some of the flattest terrain in the country.
Scientists at the British Geological Survey and the University of Oslo found it by examining zircon crystals pulled from boreholes 65 kilometres apart, in Lincolnshire and Norfolk.
England's quietest coast sits on top of a monster.
What's There
The zircon crystals — smaller than a human hair — formed in molten magma before the eruption. Their uranium slowly decayed into lead, letting researchers date the blast with precision: about 454.4 million years ago. A second, younger set of grains points to a follow-up eruption as the caldera collapsed.
The scale is hard to picture. Several hundred to a thousand cubic kilometres of crust were hurled into the stratosphere with a force compared to several thousand hydrogen bombs.
The History
The smoking gun is the Kinnekulle tephra — a vast ash layer spread across Norway, Sweden, the Baltic region, Belarus and Poland. Its source has puzzled geologists for years. The near-identical ages and matching crystal chemistry now tie that distant ash back to The Wash, blown across the ancient Tornquist Sea.
The Mystery
For all its violence, the volcano left no trace on the surface today. It explains the rugged rocks of Snowdonia and the Lake District, which share its age, but the supervolcano itself remains invisible — a ghost beneath the fields, readable only in grains of zircon.