This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Thursday, July 31, 2014

Los Angeles geyser on Sunset Boulevard!

Back in the 1970's I used to run on the UCLA track near Sunset Boulevard. Two days ago, a 93-year-old water pipe and a 58-year-old pipe broke under Sunset Boulevard near the track, sending a pulsating geyser of water high into the air.  You can view a video of it here (the video symbol in the center of the photo doesn't work because it's just a frame grabbed from the CNN video).

The track was flooded, as well as newly rennovated ($136 million)Pauley Pavilion, the home of UCLA basketball named in honor of the famous coach of winning teams back in the 1970's. At its peak, the broken pipes were sending 35,000 gallons of water per minute onto the streets, with estimates of 20 million gallons released before the flood was brought under control. Maybe the tartan track will survive, the basketball court is questionable. Firefighters had to rescue some people trapped in a parking structure
Flooded track and athletic field at UCLA

If you watch the video, you'll see that the jet is strongly pulsating. This is likely due to an effect known as a "water hammer." The pipeline was a high pressure line, and these lines are subject to very destructive forces due to the water hammer effect (sometimes called a hydraulic shock). These are pressure surges that arise when the water changes direction or momentum.  In the news, you'll see reports that the pipeline had to be shut down gradually--that's because they had to minimize the potential for water hammers. If a pipe is shut off suddenly at the downstream end (where the vent is on Sunset Boulevard), the mass of water upstream is still moving and therefore can build up high pressure.  Such shocks can cause further breakage in the pipelines. (This is common in noisy old water/steam heaters in buildings.)

Photo of Pauley Pavillion
basketball court by Jason McIntyre
I found an interesting set of numbers on Wiki about this effect: "In hydroelectric generating stations, the water travelling along the tunnel or pipeline may be prevented from entering a turbine by closing a valve. However, if, for example, there is 14 km of tunnel of 7.7 m diameter, full of water travelling at 3.75 m/s,[3] that represents approximately 8000 Megajoules of kinetic energy that must be arrested. This arresting is frequently achieved by a surge shaft[4] open at the top, into which the water flows; as the water rises up the shaft, its kinetic energy is converted into potential energy, which decelerates the water in the tunnel."

See the Wiki article for more on water hammers. 

Wednesday, July 9, 2014

Gorgeous Air New Zealand plane! (And, how much can Dreamliner wings flex?)

The new Air New Zealand Dreamliner; photo from CNN.com here
This strays from "Geology In Motion," but I can't resist--the Boeing 787 "Dreamliner" is truly a beautiful plane in flight! It's wings can flex up to 26' (150% of max load).  All aircraft are required by the FAA to be able to withstand at least three seconds of 150% maximum loads (on all structures). In January, 1995, a 777's wings deflected 24' at 154% max load (I couldn't find the actual data to check the facts--I'm using www. flightglobal.com.) Boeing actually did a break test, which you can see in this Boeing produced video. They do not say how flexed it was when it failed, however, only that it was beyond 150%! Here's a cool video (in German) of a lab test showing the flex in a way that you can actually see-it's huge--definitely worth watching this one all the way to the end to see the failure! Here's an explanation that I found on this aviation.stackexchange.com site:

"The amount of flex is really a product of the material. The wing requires a specified ultimate strength; with metal, that translates into a given amount of flex. This can be varied within limits, but it is really the material, its stiffness to yield point ratio, and its fatigue properties, that control how much flex you are going to end up with. CFRP is a very different material, and has much less stiffness for the same yield point, and has essentially no fatigue problems. This is beneficial in that it provides a smoother ride in turbulence; the wing acting essentially like a giant leaf spring. There is some lift lost due to the nature of the curvature, though. However, this is relatively small."

Monday, July 7, 2014

Super-typhoon Neoguri ("racoon") approaches Okinawa

Super-typhoon Neoguri, first super-typhoon of 2014
imaged on July 6 (?) by NOAA/EPA
A quote from my (hard working scientist) friend on Okinawa sent on Monday night, PDT: "The storm has been here since yesterday night. So far nothing comparable to the big storm last year. That one was only category 3 by the time it reached Okinawa, but a typhoon's power is concentrated in a narrow ring around the eye, and last year we were right there in the eye.  The current storm might be stronger but we are only exposed to the outer arms, at least so far, and the effects have been mild. The sound was terrifying last year; now it is merely annoying....I should be working, of course, but I have found that it is not easy for me to work during a typhoon. Perhaps I should try some cooking. I need some pasta sauce, and I have got all the ingredients in the fridge!"

Three inches of rain PER HOUR??? I wonder for how many hours!! Waves up to 14 meters (45')? I have friends on Okinawa and  wish them well (and also asked them to send a first hand report!) The storm is expected to work its way up to mainland Japan by Wednesday. The highest danger is for Miyako-jima, in the center of the archipelago.
     As I write this (Monday a.m. PDT) gusts of up to 270 km/hour (160 miles per hour) are expected, and the Japanese national weather agency is saying that this may be the worst storm in decades. This is the first storm of hurricane season there, and it is apparently hitting rather early in the season. The US evacuated some of its plane from Okinawa in advance of the storm.

Projected path and conditions, from the Japan Meteorological Agency
In my last post, I started by pondering the effect of El Nino on droughts in Japan, but did not address typhoon. But, according to research led by Ryuzaburo Yamamoto at Kyoto University and the Japan Weather Association, El Nino increases the strength of typhoons and increases typhoon-related damage in Japan. The conclusion was based on a study of typhoons over the 48-year period between 1951 and 1999. El Nino's push warm water toward the coast of Peru. Therefore El Nino storms travel further than non-El Nino storms across the Pacific toward Japan, giving them more time over warm waters before reaching Japan.

Damage from typhoons in such years is, on average, three times greater than in La Nina years, even though the average number (16.1) is less than in La Nina years (18.2). Pressures in the center of the typhoons, a measure of their strength, are, however, lower in El Nino years, producing stronger typhoons. The average number of days in which the strength (as measured by the low core pressures) was 46.3 days for El Nino and only 26.9 days for La Nina years. Average storm radius was 235.9 km vs. 180.4 in La Nina years, another measure of the effect of El Nino.

In summary, here, in the last figure, is the Accuweather forecast for the west Pacific for 2014.