Eric Holscher - Posts in link-blog

Atop the Oregon Cascades, a University of Oregon team finds a huge buried aquifer

2025-02-04T00:00:00+00:00

I’ve always had a love for the massive spring-fed rivers in Oregon. I actually got married along the Metolius River, and have done many hikes along the Fall River and Mckenzie River. These rivers are always ice cold (~40F), and keep a consistent flow year round.

I recently heard about a University of Oregon team that did some additional research on the aquifer that feeds these rivers:

Scientists from the University of Oregon and their partners have mapped the amount of water stored beneath volcanic rocks at the crest of the central Oregon Cascades and found an aquifer many times larger than previously estimated — at least 81 cubic kilometers.

That’s almost three times the maximum capacity of Lake Mead, the currently overdrawn reservoir along the Colorado River that supplies water to California, Arizona and Nevada, and greater than half the volume of Lake Tahoe.

They used previous known quantities of the water outflow, and combined it with previous drilling for geothermal test wells in order to more accurately map the area and depth of the water. Normal ground gets hotter as you go down, but the area here stays the same temperature, which lets them understand how deep the water goes.

To better understand the flow of water through different volcanic zones, the team took advantage of projects begun in the 1980s and 90s. Past scientists had drilled deep into the ground and measured temperatures at different depths as part of the search for geothermal energy resources associated with the many hot springs that pepper the Cascades landscape.

Normally, rocks get hotter as you go deeper into the earth. But water percolating downward disrupts the temperature gradient, making rocks a kilometer deep the same temperature as rocks at the surface.

By analyzing where the temperature starts to pick up again in these deep drill holes, Karlstrom and his colleagues could infer how deeply groundwater was infiltrating through cracks in the volcanic rocks. That allowed them to map the volume of the aquifer.

Previous estimates of water availability in the Cascades took the springs at face value, measuring river and stream discharge. Instead, Karlstrom and his colleagues went deeper — literally. But since those holes weren’t originally drilled with the intent of mapping groundwater, they don’t cover every area where one might like to collect such data. So the new estimate of the size of the aquifer is a lower bound, and the actual volume might be even bigger still.

I also heard an interview with the researchers on a local outdoors podcast that I enjoy, and recommend listening.

A pattern for updating dependencies in a Docker image

2025-02-01T00:00:00+00:00

We use docker pretty heavily at work, and a pattern I’ve often run into is that I want to play around in a docker image to get something working, and then be able to “save” it back into the original image. This is generally a Python dependency or something similar that we’ve put into our requirements, but rebuilding all our dependencies takes a good bit of bandwidth and time.

Run a one off command and resave the image

To start you need to get a shell in your docker image

docker-compose exec $container /bin/bash

Then you can do whatever task you need to inside that shell

pip install requirements.txt

Then you need to save the image. You could pretty easily script this to pull the hash name from the ps output, but doing it manually only takes a couple seconds.

docker ps
# Get hash
docker commit -p $hash $container

I use this pattern often when the command is pretty heavy and I don’t want to rerun the whole docker build process.

I don’t use this often enough to automate, but it would be pretty easy to do with a line of awk :)

Use Docker caching?

We have experimented with Docker caching, and it generally works pretty well. However you can definitely run into weird cases where it decides a part of the build early on has been updated, and that then requires downloading multiple GB of data again. I think of the pattern above as a way to do more explicit image updating via cache, without having to depend on any specific logic or file modified dates that might have changed in the process.

31 days of posts

2025-01-31T00:00:00+00:00

I decided to try and write a blog post each day in January, and have now been successful! I have been inspired by folks like Simon Willison, John Gruber, and Andy Baio. They are able to keep up a rate of sharing over time, at different levels of depth.

I started out trying to write long blog posts, but have been humbled by my ability to do that daily. I lowered my inspiration to a link blog, which is much more workable for a daily post. I read a ton of different stuff each day, so sharing my favorite things seems like an easy task. The hard part has been choosing what to write about, whether I want a “beat” around tech docs or AI, or want to post what is personally interesting to me.

I’m hoping to continue writing on an almost daily basis, but also want to give myself permission to not do it each day.

Nat Bullard’s deck on decarbonization

2025-01-30T00:00:00+00:00

I’ve always enjoyed this deck about the state of global decarbonization. It has lots of great high-level graphs and takeaways around the state of climate change.

He is also doing 2 parts of the Catalyst podcast, discussing some of the high-level takeaways. I thought the discussion on sulfur emissions from shipping and China’s emissions in that area were really interesting.

Society for Technical Communication (STC) shutting down

2025-01-29T00:00:00+00:00

Today there was some sad news, which is that the STC is shutting down. They posted a note on their website and other social media channels:

Despite significant efforts over the past several years by the various Boards of Directors and STC leadership, financial liabilities coupled with falling membership numbers have created a situation where we are not able to offer the education, resources, and outreach that this membership expects and deserves. Various cost-cutting measures and attempts to generate revenue have not been sufficient, and our debt and operational expenses now outweigh our ongoing revenue.

— STC Board of Directors & STC Executive Director Tim Shaw

It also got picked up on Hacker News, which had the usual mix of valuable and… divisive comments. I ended up commenting to provide some additional context, which is probably useful to share on the blog:

I’ve been working in this space for a long time, where I’m one of the co-founders of Write the Docs – we focus more on software docs.

The view from the industry is basically that STC was a bit behind the times, and was slowly dwindling in terms of reach and value. They still had some active chapters, magazine, and academic journal that provided value for folks, but membership wasn’t as valuable as it had been.

They have been around a long time, and had a wider purview that WTD, focusing on many different types of technical writing. They had members in industries like Automotive, Engineering, and Aerospace, as well as Software.

The best way to think about them is something like the ACM in the software industry. They have been taken over by more current community approaches in various areas (eg. Pycon), but also still doing some more traditional stuff that adds value but isn’t as relevant to day-to-day practitioners.

— Eric Holscher

It’s definitely a sad day, and sows more confusion and worry in an industry that is already pretty stressed by AI. I wish the STC folks the best of luck trying to shut down the organization, and I hope that Write the Docs can continue to carry the torch in some fashion.

Adam Jacobs on open source business

2025-01-28T00:00:00+00:00

I’ve been listening to Adam Jacobs on Twitter for many years wax poetic about open source business. He finally put all his thoughts together in this video, which is a great overview of free software, open source, fair source, and how to build sustainable business.

Two good Deepseek explainers

2025-01-27T00:00:00+00:00

The day has been busy with folks talking about Deepseek and it’s R1 model. I found a couple posts really useful to understand and contexutalize it:

The Short Case for Nvidia Stock - published on Saturday January 25 by Jeffrey Emanuel. It’s a long post (~60m read time) that goes through the whole context of R1 in great depth, but very readable with a bit of technical knowledge
DeepSeek FAQ - published today by Ben Thompson, which tries to cover the high level takeaways and provide context for the market reaction today which was quite large.

Staying in Europe (Schengen) longer than 90 days as an American

2025-01-26T00:00:00+00:00

When we traveled previously in 2018-2019, we spent summer in Europe both times. In general you are allowed to spend 90 of any 180 days in the Schengen visa area. This is a huge part of Europe, and was always a rush against the clock because we’d love to spend more time in Europe.

I’ve found a way as an American to spend more time in Europe than 90 days, which are bilateral visa waiver agreements, which is basically an agreement that came into effect between the USA and a Schengen country before the treaty was signed.

USA Bilateral Agreement countries in the EU

I found this information in this reddit post, which covers a lot of the background:

Certain Schengen countries have the Bilateral Agreement law, which allows you to legally stay there for additional 90 days on top of the 90 days you spend in the Schegnen area. There are many EU countries that have this law but the problem is that most don’t actually seem to honor the law because it’s so old. There’s been more online discussion on it now with Reddit, but the common knowledge seems to be based off of my guide, which concluded that it’s only actually possible for Denmark and Poland.

You can find the official EU publication on this topic, which should be all that you need to show to initiate the 90 additional days, and hopefully on departure as well. It seems like you can’t leave the country that you have the extra 90 days during that time, but it includes some countries I wouldn’t mind spending a lot of time in like Italy:

Belgium - 3 months

Denmark - 3 months

Spain - 90 days

France - 90 days

Italy - 3 months

Latvia - 90 days in any half-year period

Hungary - 90 days

The Netherlands - 90 days

Norway - 90 days

Portugal - 60 days

This is an exiting new piece of information that I wish I’d had back in 2019!

The easiest way to find an AWS instance

2025-01-25T00:00:00+00:00

For some reason AWS makes browsing their instance types surprisingly hard. I’ve found Vantage’s instance viewer the best way to figure out the best option.

A NY Times piece on Mt Bachelor

2025-01-24T00:00:00+00:00

Our not-so-little local mountain got a write up in the NY Times, which is always fun to see. It’s about a local effort to try and buy the mountain (~$200M, so some very rich locals..). Lots of funny little nods to the culture of Bend:

Mike Rogge, the editor and publisher of the outdoor magazine Mountain Gazette, summed up collective feelings in a social media post.

“The ski industry, specifically the resort side, I fear is losing the narrative,” he wrote. “Guests are your lifeblood. Locals are your culture. Without either of them you’re an empty theme park.”

The mood on the effort has turned pretty sour on our local reddit page after it was made clear that locals didn’t really have a way to “buy in”. There’s still some platitudes about trying to give locals some kind of share, if it ever happens, which it probably won’t.