We walked where the world is breaking up.
Iceland is one of the most recently formed places on earth. That is because it is so volcanically active. Steaming lava fields are common. So are inactive lava fields, glaciers, hot pools, and geysers. This makes Iceland unforgettable. Much of that elemental handiwork is the result of the awesome power of volcanoes and tectonic plates. As my guide book explained,
In geological terms, Iceland is a mere baby. No more than 20 millions years have passed since volcanoes on the floor of the far northern Atlantic Ocean began to spew lava, laying the foundations of what would become Iceland. Today it is still one of the most volcanically active spots on earth—giving geosciences the chance of observing a land still in the making.
What really astounded me is how Iceland makes visible for all to see, how tectonic platesoperate. The earth’s surface comprises a number of massive plates. There are thought to be 7 major plates and many more minor plates. Those tectonic plates are not static. Instead those tectonic plates float on the mass of superheated magma beneath them. These plates, for example, have caused the earth’s crust in many places to form huge mountain ranges. The earth is not inert, it is alive and constantly moving.
Nick Eyles and Andrew Miall have described rather well how these plates move:
“We now know that planet Earth is a giant engine fuelled by the heat generated by the radioactive decay of uranium, thorium, and potassium in its interior. In effect, Earth is a giant nuclear reactor. We live on its thin wet and brittle crust that is broken into rigid plates like panels on a soccer ball. These plates move over the Earth’s surface atop giant convection currents stirring deep within the mantle. Carrying continents as passengers, these migrating plates crate a dynamic, always changing jigsaw puzzle as one plate interacts with its neighbours. The term plate tectonics refers to the creation of new plates and inexorable destruction of old ones. .[1]
Scientists are still trying to unravel how the continents have moved. It boggled my mind when I first learned how Newfoundland was attached to north Africa and how that was discovered by Canadian geologists . Tectonic plates move, but they don’t move fast. They move at the speed that your fingernails grow (2 cm (0.75 inches) per year.
The history of how the science of plate tectonics developed is deeply fascinating. As Eyles and Miall explained,
“The concentration of radioactive elements in the mantle (such as uranium, thorium, and potassium) is very small but the mantle’s volume is so large that even after 4.5 billion years, more than 10 trillion Watts of power continues to be produced radioactive decay every second! Cooling of the Earth’s surface and heating of the interior forces motion in the mantle—a process known as mantle convection—where enormous slabs of cool dense rock sink deep into the planet below subduction zones. In addition to its own radioactive heating, the mantle is warmed by trillions of Watts of heat released from its underlying core. The core’s own heat produces 200-kilometre thick hot layer at the base of the mantle …. Gigantic columns of hot buoyant material known as plumes, rise from this layer and slowly creep upwards towards the surface. Diamonds ejected to the Earth’s surface through kimberlite pipes originate in this layer. Convection of the Earth’s deep interior drives the relentless motion of tectonic plate of the Earth’s crust. Despite its long history, the Earth has an enormous reserve of heat yet to be realized: consequently, the process of mantle convection, and thus plate tectonics will continue for billions of years to come.[2]
Most geological activity around the world is concentrated along boundaries between plates as, for example, the famous Pacific Rim or Iceland. This is caused by the dynamic interaction of one plate with an adjacent plate or plates.
Volcanoes and earthquakes are symptoms of these moving plates colliding with each other at the place where tectonic plates meet. The boundaries of the plates can be convergent or divergent. Where the plates move together they are called convergent plates. Where the plates move apart they are referred to as divergent plates. Where plates are divergent they tear apart and then magma rises to the surface of the earth at that place. As a result this magma forms a new crust of the Earth. Where the edge of one plate the edge of one plate is forced underneath another plate mountains can rise up. This is what we saw first hand in Iceland as these photographs clearly show.
Iceland straddles a divergent boundarycalled the Mid-Atlantic Ridge where the Eurasian and North American tectonic plates are being pulled apart. We saw that clearly in Pingvellir where a UNESCO world heritage site has been declared as a result of that and its unique contribution to world culture (the world’s first parliament). It was astounding to see. According to our guide AO this and Africa are the only two places on the planet where this can actually be seen as clearly as this.
Pingvellir is the place where the two halves of Iceland and a good part of the part world, are breaking apart. The Eurasian and North American tectonic plates tear apart right here. We actually walked right through the place where the world seems to be splitting apart!
Iceland created the world’s first commonwealth or Parliament at this same site in about 930 A.D. . This was the first Parliament in the world and the Icelanders are justifiably proud of it. While the rest of the world was “governed” by the feudalism system as in Europe or even worse in many other places, Iceland had a commonwealth though it was not yet democratic. Icelanders wanted to make sure they were not rule by one king. Some countries now seem to be in danger of going back to such a system.
