Beachcombers

LOW TIDE: We started the morning with a trio of Week 7 lectures for our Einstein class. When I spotted a break in the weather, we sprang into action to take advantage of it while we could, leashing up the dogs, and the kids got their scooters and helmets.

We decided to head down to the Terminal 91 park along Elliott Bay. There, we can see fishing vessels, cruise ships, the Space Needle, the stadium district and part of downtown, and more.

We happened to hit it at the lowest tide we've ever seen down there. Given that, there were lots of shells and seaweed to check out.

One of the interesting things we spotted was this small boulder. It seemed to have a clay or brick bottom. I sent this photo of it to the geologist in the family to see what he had to say about it.

Tonight, we heard back from Dr. Jim Haggart. He said ...

It's hard to say just what the rock is, without seeing it closer.  However, I can make some guesses.  The interesting thing is the little holes that seem to be in the upper part of the rock.  These could be molds of fossil clam shells within a sedimentary rock, or they could be vesicles (irregular gas bubble holes) within a volcanic rock.

The red-brick stuff on the bottom could be partially lithified Pleistocene mud or clay (the stuff they make bricks out of!) and, if it is a volcanic rock, the abundance of iron in such a rock would provide a ready source of iron to oxidize within the mud, producing the red color.

If the holes are actually fossil molds, it is possible that this could be an erratic boulder (carried by the ice) from the fossiliferous Cretaceous rocks that are found in the foothills of the Mount Baker region (similar erratics are known to have been carried from Harrison Lake (Look on Google Earth) in British Columbia to the central part of the Olympic Mountains!)

However, I suspect it is most likely the volcanic option.  Too bad you didn't use the camera to get a close-up view, as the composition of minerals and/or grains can tell a lot.

Super interesting! And now, of course, we want to go back and find the rock to get some closer shots of it. I hope the water doesn't carry it away before we can get back!

We probably spent a half hour enjoying the great outdoors before it was back to physics.

We noted that the sundial in the park was keeping good time today.

As is their tradition, the kids celebrated when the reached the top of the loooong hill we have to climb on the way home.

NOTEWORTHY: Guess what we did this afternoon? More Einstein! We're playing catch up because we were gone last weekend, and last week's darn problem set slowed us down for a couple of extra days.

Here are some of Annabelle's notes from this afternoon. I love them. :)

BREAKING NEWS: And by breaking, I mean a freaking bridge collapsed. Specifically, the Interstate 5 bridge over the Skagit River. It's about 100 miles north of Seattle, and we last crossed it on our field trip to see the tulips. Around 70,000 cars cross it each day. It fell into the river at about 7 p.m. tonight.

Initially, it was hoped that there were no casualties, but by 9 p.m. there was a report of at least one casualty.

In the days and weeks to come, we'll find out why the bridge collapsed. The Associated Press reported that the bridge, built in 1955, had a sufficiency rating of 57.4 out of 100 according to federal records. That's pretty awful, and well below the statewide average rating of 80. It was labeled 'functionally obsolete' years ago.