Tuesday, June 30, 2020

Meanders, Oxbows, and Time


My colleague, Brad Dimock, sent along a link recently that I know you will find interesting. It involves a cartoon graphic that shows the way mature rivers meander and evolve through time. You will see meanders turn into oxbow lakes that are cut-off from the main stem, then fill with sediment. You will see point bars grow as meander loops arch outwards. You could look a this for a half hour and not see enough. The site was constructed by Robert Hodgin. Watch it here. Thanks Brad!

Here are photos I took of the upper Amazon River near Iquitos Peru in September, 2009. You can easily see the meanders and oxbow lakes. Imagine that these are migrating and moving just like in the graphic above, but on a much slower pace. 








Saturday, June 20, 2020

Why no blogs...?

Palisades of the Desert from the Colorado River, September 17, 2013
I think everyone will agree it has been a difficult few months. While I weathered the pandemic and its consequent isolation fairly well in March, April, and May, I seemed to falter a bit in June. I miss traveling. I miss lecturing. I miss being on the river looking at the Grand Canyon. I know it is difficult for many of us right now. But we have to keep in mind that we, as a species, aren't calling the shots right now. That can be difficult for some - to admit that we are helpless against nature. But why should we be against nature. No matter how difficult it is for the both of us here, we are doing what we can to limit the spread of the virus. We do it for us. And we do it for others. It has been especially hard on my wife not seeing the children or grandchildren. But we want to be good citizens.

There are really two reasons why I have not been blogging since the end of May. The first is that there is nothing to say. I haven't been anywhere, haven't done anything. So why force it. I can take a break - I hope you will stick with me until we come out on the other side. The second reason is that I have been working on a project. I am a co-author on an upcoming geologic river guide for the Grand Canyon. Since the end of April, I have been plugging away at the keys of my computer, transferring my river observations into readable text. A sample spread is included below. There will be a geologic map on one half of each spread and a mile-by-mile description on the other half. My co-author is Dr. Ryan Crow at the USGS here in Flagstaff and the book will be published by them. I am excited to be working with Ryan - he has researched the lava fields found in western Grand Canyon and brings great expertise to the project.

I am hoping the guide will be ready for the 2021 river season. For that to happen, I will have to take significant time away from blogging and dedicate that time to finishing the guidebook. I will try to post something now and then from previous trips, and I may even dip into my vast collection of photographic slides from days long before this blog existed. There are some good ones. But right now I need to focus on the book and maintain some sanity during the necessary isolation.

Just letting you all know there may be less blogging through the summer. My enthusiasm for travel, geology, landscapes, and exploration remains high. Thanks for your understanding.