A Toe in Lake Tahoe

2 Comments

So I spent a few days in Lake Tahoe. Well, I wasn’t in Lake Tahoe for a few days, more like a couple minutes. And I was in all the way to my ankles. But I was in the area for a few days. Was it ever gorgeous.

I dare you to click on that and not fall instantly in love.

More

I left my <3 in San Francisco, Part Three: Field Trips

Leave a comment

I took another field trip during my stay in the Bay Area: to Napa Valley. Unfortunately, I picked Labor Day weekend to do this, and everyone else in the Western Hemisphere was doing the same thing. Between the crowds and the fact that I was driving, I abstained from imbibing the local spirits.

But, like me, my day was not totally wasted, because I found a few geologically interesting places. The thing that most defines Napa Valley, besides the wine, is the volcanism. Back when there was subduction happening on the coast of California, there was a string of volcanoes along the continental margin, usually 50 to 200 miles from the subduction trench. This is always the case when you have subduction because that oceanic plate dives into the mantle, melts, and goes the only way it can go: up! This is still going on in the Cascades, as well as in Alaska, and Japan, and Chile…hey that’s pretty much the whole Ring of Fire thing, isn’t it?

More

I left my <3 in San Francisco, Part Two

Leave a comment

While I was in the Bay Area, I did some touristy things, like riding the cable cars.

More

I left my <3 in San Francisco, Part One

Leave a comment

I love San Francisco. I really do. I’m not really much of a big city kind of girl, but San Francisco is one of the few big cities where I would willingly live. Except that it’s really, really expensive. And hilly. Ask my calves.

Of course, what other picture could I use to lead off my memoir of San Francisco:

More

Sleeping on the San Andreas, Part Three: Field Trips

Leave a comment

In parts one and two, I talked about how the San Andreas fault formed the San Gabriel mountains. While I was spending the week sleeping in those mountains, I took field trips to a couple geologically fascinating sites in the California desert that are not directly related to the San Andreas, but are nevertheless evidence of the fascinating tectonic history of California.

The first stop was Rainbow Basin, near Barstow. This lies in an area that was once occupied by a shallow lake. The area is also the home of the Calico fault, which runs parallel to the San Andreas. On this map, the Calico fault is #21; the San Andreas is #30.

Like the San Andreas, it is a right lateral strike-slip fault. Also like the San Andreas, it has a bend in it. Which means that it creates local compressional forces while the blocks on either side try to slide past each other.

This is the beautiful result:

More

Sleeping on the San Andreas, Part Two

Leave a comment

In part one, I talked about the San Andreas Fault and how it worked to create the topography of the San Gabriel Mountains. In this part, I’m going to show you some of the signs of the fault’s activity in the Wrightwood area.

The day I arrived at the campground, I saw a bulletin that there would be a volunteer-led hike the next day exploring the San Andreas. Of course, I was thrilled!

More

Sleeping on the San Andreas, Part One

Leave a comment

I’m about to share a huge part of my childhood with you. When I was a kid, my family spent most weekends every summer camping in the Angeles National Forest near Wrightwood, CA. We also went up there in the winter to play in the snow. That’s the nice thing about living the Los Angeles area: you can drive a couple hours, play in the snow, and drive home where there is no snow.

We went on a lot of ranger-led hikes (something they don’t seem to do anymore, which I think is a huge loss) so I always knew that whole area was resting right on top of the San Andreas fault. I was familiar with the terms “fault flour” and “slickensides”, even if I couldn’t tell you precisely what a fault was. I just knew it was going to be the source of The Big One, something that lives uneasily in the backs of the minds of everyone who lives in California. More

Older Entries