Rainy Day Mood

The Richard H. Chambers Ninth Circuit Court of Appeals Building, seen from the Lower Arroyo

It didn't rain all day yesterday, just all morning. Still, I was in a rainy day mood. I craved the cozy feeling of running the heater and drinking hot tea, and I indulged.

One cloudy day some time ago, PDP's resident geologist Becca and I took our dogs to the Lower Arroyo thinking it wasn't going to rain. It did, of course, as soon as we were as far from our cars as we could possibly get. We were the only non-wild creatures in the Arroyo between the Colorado Street Bridge and South Pasadena. Everyone else, wild or not, knew enough to find shelter.

It began to pour, rattling the leaves and forming puddles on the path. The stream ran full from north to south. Becca and I were soaking wet. We let the dogs run free and they were out of their minds with the joy of it.

Yesterday, Boz curled himself into the shape of a Lima bean and spent most of the day by the heater, with the exception of our neighborhood walk. Now that he's older he craves being cozy, too. Because I know the feeling I run the heater for him, but he turns up his nose at tea.


Here's another view of the Courthouse from the Arroyo, with Boz posing in the foreground.

Geology Lesson #3

It's been a while since Pasadena Daily Photo's resident geologist paid us a visit. Earlier this week, Becca brought her geology students to the Arroyo Seco on a field trip. I asked her to tell me about it:

"The students are enrolled in physical geology at Mt. San Antonio College (Mt. SAC). This field trip to Hahamongna was to get their feet wet (no pun intended!) before going on their overnight field trip next week to the Mojave Desert. Some of them had never seen a fluvial system (river) before. Several of them were super-sunburned in class [the next day]. They did a great job--I really enjoy working with them."

Boz and I met the group out on the northwest reaches of the flood plain in Hahamongna Watershed Park, where they'd spent the previous hour in the riverbed identifying the many different types of rocks washed down from the mountains in last winter's storms. Then we guided them southwest to this location:

This semester, the class is writing a feasibility study on the proposed athletic field at Hahamongna. Boz and I were invited along to show them where the field is going to be. That's the spot, right there.

I enjoyed meeting the students. They were interested, inquisitive, polite, smart and just generally pleasant to be around. According to Becca, most of these young adults are from the city and get their first taste of nature from these field trips. I hope they had a good time in the Arroyo and, more importantly, I hope they learn an appreciation of nature and its preservation.

While we stood on the shore, Becca quizzed her students about the topography and geology. They asked questions of her and of me. Boz strained at his leash. The water's kind of smelly because at this spot it's standing water. The only thing Boz likes more than stinky water is stinky water with mud.

Geology Lesson #2

February has been too much fun. Let's get serious and learn something here on the old blog. (Not that learning can't be fun.) Since we have a resident geologist at Pasadena Daily Photo, let's take time out for a geology lesson. After all, there's geology all over Pasadena.

Here's our geologist, Becca, posing like a product model with a sedimentary deposit we found in the Hahamongna watershed basin. Becca adores sedimentary deposits. She explained it to me while I was taking the picture, but I didn't remember a word of it. So she sent me this email:

"In our last lesson we learned about graded bedding, in which the particle size decreases as one moves up a particular layer or bed. In contrast, this sedimentary deposit is a disorganized mix of pebbles and cobbles. A geologist would characterize this kind of rock unit - one in which a variety of particles are observed - as 'poorly sorted.' Upon closer inspection the geologist would also note that these are the same rock types that make up the San Gabriel Mountains, located several miles north of the Hahamongna watershed."

Then she throws a pop quiz into her email:

"How do you think these rocks were moved all the way from the San Gabriels to this basin?"

Becca gives three choices for an answer: wind, water or glaciers. I say it's water. Hahamongna's a watershed basin after all. I don't know when the glaciers were here last and I'm no geologist, but I'm pretty sure wind doesn't move rocks.

"Another observation about this deposit," Becca says in her email, "is that it's been heavily weathered. Weathering is the process by which rocks are broken down mechanically (size and shape changes) and chemically (the removal of minerals and addition of new minerals). Notice all the plants growing in the rock unit. This is an example of a physical weathering process called root wedging, during which roots force their way into the rock/deposit, breaking the rock into smaller pieces."
We also noticed some of the rocks had a rust-like coating. Becca says oxidation occurs when iron-rich minerals are exposed to oxygen, creating the reddish-brown stain. Aha! Like rust. Oxidation is a chemical weathering process, like she described. So this sedimentary deposit is going through both chemical and mechanical weathering.

And, Becca says, the end product of weathering is the development of soil. I love that. It's so logical.

I hope I was right about the rocks being moved by water. I was applying logic, after all. It's less logical for them to have come down from the mountains by glacier, don't you think? And by wind? There's no logic in that whatsoever. Whimsy, maybe, but really it's just plain dangerous.

Geology Lesson #1

Today John and I will be enjoying an apres-Christmas dinner with Pasadena Daily Photo's new staff member. You heard me right. I'm pleased to announce PDP now has a resident Geologist (Pasadena resident, that is). Her name is Becca and she's Sprocket's guardian.

During our dog walks I get the occasional geology lesson. Who knew there was so much geology going on in Pasadena? My god, it's happening all the time, right under our feet!

About this photo, Becca says:
"This is a nice example of graded bedding. When water flows through the stream channel it transports material of various sizes. Fast-moving water transports relatively large sediment such as boulders, cobbles, and/or pebbles. Slow-moving water only has the energy to move small sediment such as sand, silt, and/or mud. Imagine taking a jar filled with water and sediment of various sizes, shaking the jar and placing it on a table. The larger sediments will settle to the bottom first, and as the water current in the jar continues to decrease, progressively smaller sediments will settle on top.

"As a side note, if these sediments were buried and left undisturbed, they could go through a process called lithification and turn into a sedimentary rock. And then, my friend, this beautiful graded bed would be preserved in the rock record!!"

Many of Becca's colleagues have gone off make money drilling the planet for oil. Becca's dream is to transmit her love of the planet to her students. "If one of them picks up a piece of litter and puts it in a trash can, I've done my job," she says.