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Volcanoes are the ultimate earth-moving machinery. A violent eruption can blow the top few kilometers of mountain, scatter fine ash practically all over the globe and hurl rock fragments into the stratosphere to darken the skies a continent away.

But the classic eruption – cone-shaped mountain, big bang, mushroom cloud and surges of molten lava- is only a tiny part of a global story vulcanism, the name given to volcanic processes, really has shaped the world eruption have rifted continents, raised mountain chains, constructed islands and shaped the topography of the earth. The entire ocean floor has a basement of volcanic basalt.

Geologists consider the earth as having a molten core, surrounded by a semi-molten mantle and a brittle, outer skin. It helps to tyhink of a soft-boiled egg with a runny yolk, a firm but squishy white and a hard shell. If the shell is even slightly cracked during boiing, the white material bubbles out and sets like a tiny mountain chain over the crack- like an archipelago of volcanic islands such as the Hawaiian Islands. But the earth is so much bigger and the mantle below is so much hotter.

Even though the mantle rocks are kept solid by overlying pressure, they can still slowly flow like thick treacle. The flow, thought to be in the form of convection currents, is powerful enough to fracture the ‘eggshell’ of thr crust into plates, and keep them bumping and griding against each other, or even overlapping, at the rate of a few centimeters a year. These fracture zones , where the collisions occur, are where earthquakes happen. And very often volcanoes.

Volcanoes have not only made the continents, they are also thought to have made the world’s first stable atmosphere and provided all the water for the oceans, rivers and ice-caps. There are now 600 active volcanoes. Every year they add two or three cubic kilometers of rock to the continents. Imagine a similar number of volcanoes smoking away for the last 3500 million years. That is enough rock to explain the continental crust.

What comes out of volcanic craters is mostly gas. More than 90% of this gas is watyer vapour from the deep of the earth:L enough to explain, over 3500 million years, the water in the oceans. The rest of the gas is Nitrogen, Carbon dioxide, sulphur Dioxide, methane, ammonia and hydrogen. The quality of these gases, again multiplied over 3500 million years, is enough to explain the mass of the world’s atmosphere. We are alive because provided the soil, air and water we need with the blessings of the Almighty God.