It's all San Andreas' Fault

On a visit to the Point Reyes National Seashore, we began by walking the Earthquake Trail. The displacement between the sections of fence in the photo above (lower to the left, upper to the right) shows the extent to which the land was shifted by the great 1906 earthquake that devastated San Francisco.

The three posts marking a line going toward the fence in the background show the approximate alignment of the San Andreas Fault. The Fault roughly marks the boundary between the North American and Pacific tectonic plates. So, I can say that, when I took this photo, I was standing on the Pacific Plate, to the west of the Fault, looking at the North American Plate, to the east (and right) of the line extending through the posts.

Fortunately for me, the earth did not move during my visit to this very excitable spot. I'm told that Northern California experienced a small earthquake a few days after we left.

A note to a reader in San Francisco.

To whoever got here via a Google search for "sea level rise and Brooklyn Heights Promenade": believe me, if all the arctic and antarctic ice were to melt, the Promenade would still be above water.

This isn't to say we're not concerned about climate change here. After all, most of us work in lower Manhattan, which lies much closer to sea level. Moreover, we'd hate to lose the piers that will support much of the new park planned below the Promenade.

Incidentally, the Heights are a product of the last Ice Age. We sit on the lower boundary of the continental glacier at its maximum extent, and the high ground consists of debris pushed southward by the glacier as it grew, then left behind as it melted.

Continental collision zone.

Kudos to Twiffer for referring me to another NASA site, Visible Earth, which features images of earth made by satellites or by astronauts on shuttles. This image is of a portion of northern Sudan, taken with a radar instrument carried aboard the shuttle Endeavour. The radar exposes hidden sub-surface features, such as, in this instance, rock formations covered by desert sand. The curving green band on the left side of the image is the Nile and its flood plain. To the right of the Nile is a nearly straight line separating reddish from yellowish portions of the image. This is a fault line that delineates a collision between two ancient continents which happened 600 million years ago. Further details can be found here.

"Winter is icumen in, ...

... Lhude sing Goddam"

-Ezra Pound

This fall has been unusually mild, with temperatures here in New York typically topping off in the mid 60s, and getting no colder than the high 40s at night. Today, it's supposed to get up to near 70, but then, the storm that's now blasting western New York State and Pennsylvania will get here, heralded by winds predicted to gust as high as 60 miles per hour. Things will cool off a lot, with highs next week in the 40s and lows at night just above freezing. In other words, we're in for some weather I'd consider normal for early November in this part of the world. Global warming? Maybe.

If you're looking for some visuals and text that will really cool you down, I recommend this blog by David Ruth, a sculptor who works in glass, and who has been given a National Science Foundation grant to spend just over a month at Palmer Station, on the Ross Ice Shelf that extends from Antarctica. Ruth's mission is to study the qualities of ice and its relationship to glass, and he posts lots of pictures of fantastic ice forms, interspersed with photos of, and text about, Antarctic wildlife and the people and facilities at Palmer. Well worth a visit.