A small rock in the Atlantic

Sunday, 16 March 2008

The Caldera

Most people say La Palma is the most beautiful of the Canary Islands. And practically everybody agrees that the most beautiful part of La Palma is the Caldera de Taburiente.

In 1825, the German geologist Leopold von Buch studied the Caldera de Taburiente and concluded that the crater was formed by the emptying of a magma chamber below. He was sufficiently impressed with it that he gave the name "caldera" to all such formations. (See http://en.wikipedia.org/wiki/Caldera). Mauna Loa, on Hawaii, has a caldera. Olympus Mons, on Mars, has a caldera.

And the Caldera de Taburiente isn't a caldera! Von Buch got it wrong. It looks like a caldera, but it was actually formed by erosion.

However I formed, the Caldera is impressive. It's 5 miles (8 km) across, and most of the rim walls are almost 6,000 ft (1,800 m) above the floor. I've heard several people say that it looks bigger than the Grand Canyon, because your brain can just about cope with the size of the Caldera, and it just gives up with the Grand Canyon.

The geology is spectacular, but the most special thing about the Caldera is the water. The Taburiente is the only year-round river in the Canary Islands. True, a lot of water is taken out for irrigation, so that in summer the "estuary" is reduced to an underground trickle. But, except in the driest summers, you can hike all day without a water bottle, just drinking from the streams as you cross them. (But take an empty water bottle unless you're pretty flexible. It's a lot easier to fill the bottle and then drink, than to get both hands down to the water.) That means lush vegetation in the lower parts, even willow trees.

Most of the Caldera (18.3 square miles, or 46.9 km2) became a National Park in 1954.

More photos to follow soon.

Labels: Caldera, Canaries, Canary islands, La Palma

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Monday, 11 February 2008

The Caldera

The heart of the island is the Caldera de Taburiente.

Caldera is a technical geological term for the crater at the top of a volcano. In fact the term comes from La Palma: all the volcanic calderas in the world were named after ours. So it's really a pity that, since then, the scientists have found out that the Caldera de Taburiete isn't a caldera. It was actually formed by erosion and a gigantic landslide.

However it was formed, the Caldera is spectacular. In most places it's eight kilometres (five miles) across, and many of the rim walls are 1,500 metres high and almost sheer. I haven't seen the Grand Canyon yet, but people who've seen both frequently say that the Caldera looks bigger. You see the Caldera is just on the edge of what your brain can understand, whereas it just gives up when faced with the Grand Canyon.

The Caldera is surprisingly hard to photograph well, because you loose the sense of scale. This photo was taken from the observatory late one morning, and the scale mostly comes from the aerial perspective - the way distant objects are bluer. On this day there was just the right amount of dust in the air to give a sense of scale without hiding more distant details. I like the way the sunlight catches the cloud waterfall.

Labels: Caldera, Canaries, Canary islands, La Palma