“The Earth…” whispered Arthur.
“Well, the Earth Mark Two in fact,” said Slartibartfast cheerfully. “We’re making a copy from our original blueprints.”
There was a pause.
“Are you trying to tell me,” said Arthur, slowly and with control, “that you originally… made the Earth?”
“Oh yes,” said Slartibartfast. “Did you ever go to a place… I think it was called Norway?”
“No,” said Arthur, “no, I didn’t.”
“Pity,” said Slartibartfast, “that was one of mine. Won an award you know. Lovely crinkly edges. I was most upset to hear about its destruction. … Perhaps I’m old and tired, but I always think the chances of finding out what really is going on are so absurdly remote that the only thing to do is to say ‘hang the sense of it’ and just keep yourself occupied. Look at me – I design coastlines. I got an award for Norway. I’ve been doing fjords all my life… for a fleeting moment they became fashionable and I got a major award.”
And with that rather fitting introduction from Douglas Adams – one of the sources of inspiration for Mostly Harmless Science – let me introduce to you Norway’s fjords, or as I like to call them, those “lovely crinkly edges.”
If you look at a map of Norway, you might notice that the coastline is crisscrossed with long thin ‘fingers’ of water reaching inland from the sea. These features, fjords, are not unique to Norway and can be found along other northern coastlines including Greenland, Iceland, and Canada. The term traces its roots to the Norse word ‘fjodr’, which refers to a body of water used for human passage.
Fjords differ visibly from other bays and inlets, both in their long sinuous forms and steep-sided cliffs. From the water, the effect is spectacular. The rock walls bounding the fjord rise sharply out of the water on either side, interrupted only by glaciers and waterfalls as they come down from the mountains to meet the water.
So what do the above countries have in common? Well, for much of the Pleistocene epoch (the geological age between 2.6 million and 12 thousand years ago), they were blanketed by ice sheets, at times up to 3 km (2 mi) thick. Just like rivers (but a tad more slowly), glaciers flow from higher elevations down to the sea. As they flow, they carve out deep U-shaped valleys. Glacial landscapes also include such features as horns and arretes (sharp peaks and ridges), cirques (bowls), and moraines (jumbled rock deposits marking a glacier’s edges). With the end of the last ice age approximately 12,000 years ago and the resulting melt of these giant ice sheets, global sea level rose dramatically. Many of these large valleys were flooded, producing fjords.
Although Norway’s deepest fjord is more than 1,300 metres (4,300 feet) deep, as a general rule, they are often much shallower where they meet the sea. If you could look underwater at one of these locations, you would see a terminal moraine – a large pile of rocks that marks the furthest extent of past glaciers in the valley. In some cases, these mounds are large enough to partially cut off fjords from the open sea. In Norway, many fjords join at sharp (often 90 degree) angles, giving the coastline a ‘jagged’ appearance. This is because glaciers didn’t just carve valleys at random, but rather occupied existing faults – cracks formed during mountain-building millions of years earlier.
Here are some photos of my adventures in Norway:
Be warned: you may have just sustained a lethal dose of mostly harmless science.
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Map and satellite image courtesy of Wikimedia Commons. Photography by Mostly Harmless Science.