A Giant’s Stepping Stones


T e ground cracks open. Clouds of hot gases and steam billow into the sky. Sizzling hot lava spills out of the giant cracks. It oozes across the ground. T e lava covers everything in its path.


Nothing is safe. T ick forests burst into flames. Streams and ponds boil. Animals flee. Yet the lava keeps coming. Eruption aſt er


eruption, it fills a river valley. It forms a lake of hot, molten lava 90 meters deep. T e lake is so deep that the lava cools very


slowly. As it cools, it turns into igneous rock. It also contracts, or shrinks. T en, crack! Soon, small cracks cover the entire surface


of the rock. T e cracks form hexagon shapes. T ey make the rock look like a honeycomb. Many of the cracks are very deep. T ey turn the rocks into columns. T ese columns stretch all the way to the buried river valley.


12 NATIONAL GEOGRAPHIC EXTREME EXPLORER Over the years, more lava bubbles up. It


covers the land. So do dirt and grass. T ey bury the columns, hiding them for millions of years. Yet the land keeps changing. T e sea rises. It floods the land. Sea levels


drop. T e receding water tugs at the land. Waves pound it. Winds blast it. Over time, these powerful forces wear away the land. Bit by bit, the cracked lava rock reappears.


T e columns aren’t all the same height any more. Some look like giant stepping stones. T ey stretch to the sea, forming the Giant’s Causeway in Ireland. More columns form a cliff . T ey look like giant organ pipes. Lava doesn’t erupt here any more. Waves


and wind still beat this place, though. T e tough rock slowly wears away. Someday, like the land that once covered it, the columns will crumble. Giant’s Causeway will disappear.


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