Tuesday, January 20, 2009

Cusp

It has been unusually clear here, after a weekend in which a tropical storm pushed through, threatening high winds. As a result, the mountain peaks at the head of our valley, usually swathed in clouds, are visible for once, and the distinctive skyline of my neighborhood is clear:

skyline

The camera focused on the passive-solar hot-water tank in the foreground, rather than on the mountains in the background, so you really don't get the sense here of how crystalline the air has been, as if everything is seen through a giant magnifying lens. Usually there is a haze of humidity in the air that obscures distant vision. The strange clarity makes distances seem smaller, as if you could reach out and touch the sharp ridgetops.

I grew up in a part of the world where the mountains are made of granite, old and worn-down and smooth. I grew up thinking that old mountains are rounded and gently shaped. When I first saw the breathtaking crags of the Rockies, I thought, this is what young mountains look like: all knife edges and sheer faces and angles.

But when you live on a shield volcano, you learn that it's the rounded, smooth mountains that are the youngest. The lava flows so slowly out of this kind of volcano that it forms a gentle, rounded slope rather than a dramatic cone (which was deeply disappointing to a four-year-old of my acquaintance, when he finally got up close and personal with Kilauea). Cliff faces and sharp ridgelines are formed by the landslides and erosive processes of aging mountains. The most dramatic pali cliffs and toothy ridges of our own island are signs of the progressive destruction of the old volcano by time and wind and water. The skyline shown here is the edge of a giant caldera wall, seen from the outside (we live in the zone between two ancient shield volcanoes, each now half fallen into the sea). These are the old mountains, by the standards of the Pacific Ring of Fire, anyhow; and the deceptively gentle slopes of Mauna Kea, rising nearly 14,000 feet above sea level, are smooth and rounded and brand new.

1 comment:

gpwieland said...

True where you are, anyhow. The mountains in the Eastern US are older and more rounded than the Rockies simply due to both of them not being volcanic.