According to the theory of continental drift, the earth's crust is composed of 7, 8 massive plates and several small ones. Island is quite the only place you can see the fault between the North American and Eurasian plates.

Here, if you're place in front of the bridge, America is on your left (west), and Europe on your right (east). These two plates are drifting apart at an average rate of about 2cm each year.