Now, approaching the summit, I can see Dalfjall. Rather than a mountainous peak, it is a huge notch: Ravens Notch. I stop to gape at the gap. I have been here three times before, most recently three years earlier, when the gap was three inches (7.6 cm) smaller. The sight of it still takes my breath away. For this is the spot where the Mid-Atlantic Ridge—the underwater mountain range that runs down the center of the North and South Atlantic—reveals itself on land in all its geological glory.
Ravens Notch grows wider every year and is evidence that the mountain is slowly being pulled apart, as is Iceland and the Eurasian and North American tectonic plates, which face each other across the ever-widening Mid-Atlantic Ridge. Fortunately for Iceland, the island itself will not split in two because volcanic activity repairs the rift as the plates move apart. Still, in another hundred years or so, the gap could possibly have widened by an additional seven feet (2 m), although the movement happens in fits and starts. In the Krafla area, the most intensive bursts of activity were in 900 AD, 1724–29 and 1975–84. During those periods, Ravens Notch might have widened by three to six feet (1–2 m) in a decade. In the periods between, the movement has been less dramatic.
It may not seem much, but such is the way that landmasses shift, rupture, split apart and re-form over millions of years. The journey of geological time, the path of new continents, begins with an inch a year. Here in Iceland, as in few places on Earth, one can experience violent geology on a regular, often alarming basis. Strolling to the summit of nearby Námafjall Ridge, I can look southwest along the great series of fissures in the Earth—some buried under ice or rock, others all too visible—on a course across Iceland that leads toward the Reykjanes Peninsula, near Reykjavík.