Highs and Lows

Nope, not about politics -- that's pretty much lows these days. It's about mountains and deep sea trenches, in the news because director James Cameron just dove to 35,756 feet below sea level. That's in the Marianas Trench, which is fairly close to Japan.

There are a number of trenches in the oceans, places where one plate of the crust is being forced under another, also known as "subduction zones." The Mariana Islands, which are right there at the edge, are the result of volcanism from the activity of the two plates. But the Marianas Trench is the deepest.

That got me to thinking: what's the highest point above sea level? Well, yes, it's still Mt. Everest, at 29,029 feet. It's probably safest to stick with "above sea level" because if you start looking at "highest mountains," you have to take into account sea mounts. Mauna Kea, for example, is only 13,802 feet above sea level. From its base, however, it measures 33,474 feet. That's over six miles -- normal cruising altitude for a commercial jet liner.

And yet, all these mountains and trenches are just bumps and wrinkles on the surface of the earth. Just to put things in perspective.

Footnote: Think about cranes. They summer in Siberia, and then migrate to India and Southeast Asia in the winter. Over the Himalayas. That's pretty amazing.