Yosemite Hazards Vol 3

While in California, we had to give a 20 minute presentation on a topical research area of our choice. My presentation was about using LiDAR to measure fuel loads of forest canopies. Others spoke about native inhabitants of the Yosemite Vally, giant redwoods, and animal species. One topic that I found very interesting was presented to us by fellow classmate Jerrod. He told us of the ongoing efforts to prevent nuclear meltdown in Fukushima, Japan. I thought this was an event worth briefly discussing.

Failure at the Fukushima Nuclear Power Plant occurred on March 11th of 2011. It was result of the plant being hit by the tsunami triggered by the Tohoku earthquake. It is reported as the largest nuclear incident since Chernobyl. Source.

Although I will admit, I am not religious in following news, I like to believe that when a situation has the ability to scar the planet like Chernobyl, I will be at least aware of it. Whether I should blame myself, or Brian Williams (love the guy) can be saved for another blog. I just wanted to point out some of the key details of this event, and I'll start with a map.

The green circle around fukushima is an area that was (and could be still) under radiation watch, however the main thing I wanted to point out, is that the blue colored areas on the map represent the ocean. Oceans are known to produce some wave action which can be greatly amplified by hurricanes and earthquake induced waves. I know, I am reading like a jackass. But I guess it makes me a little worried that there are people with significant sums of money who can make decisions like this that have the ability to change the planet.

I understand there are benefits to the location. A big one was the vast water supply to cool reactors. And I know that it has produced a great amount of electricity for the people of Japan. I just wish with such high stakes, they could have built the sea wall with some extra generosity. (Their sea wall was 10 meters high, while the tsunami threw a wave of 13 meters)

Yosemite Hazards Vol 2

Another hazard I took the liberty of identifying while in the park, was rock falls! On our second day in the park, we were lucky enough to have the sole park geologist give us a tour, and grease the geomorph skids for the following days to come. On our walk through the valley meadows, he pointed out rock falls and their hazardous nature.

He told us how comfortable we should feel in our tarp tents located closer to the middle of the valley. He told us that there is at around a dozen rock falls in a year, and a significant one in a decade. We stayed in Curry Village. A few years back, there was tarp tents built closer to the valley walls. They are not there anymore because a house or two got steam rolled by a car sized boulder. When going back to the village, I walked towards the south and closer to the wall. The steam rolled huts were replaced by an ampitheatre. They found that there was a significant risk and so they started building the huts closer to the center of the valley.

Having such a large economy fed from tourism, we can only expect growth. So an interesting question to ask is: how long until we are forced to flirt with higher risk property?

The link below is the source I've used for tourism numbers.
http://www.nps.gov/yose/naturescience/park-statistics.htm

Yosemite Hazards Vol 1

As I stated earlier, we did research on the El Capitan moraine. It's interesting to think about, as (due to Nat'l Park restrictions) being able to perform research there is not an easy thing to arrange. That can be one claim to this University's greatness, but anyways. 

We used a geographic technique called ground penetrating radar (GPR). I have been using this technology for a year now and it is one of the best ways to analyze subsurface stratigraphy. We use this technology to non invasively see how layers have been built upon each other over thousands of years. So you can guess why we used it. We were(/are) looking to uncover more information about the geologic history of the area: specifically in the valley.

But this moraine has an interesting story to it. In the early human development of Yosemite Valley, flooding was a big problem. The merced river would tend to get backed up behind the moraine and flood out everything. Bugs were also a big issue as the area would get almost swampy. To rid themselves of this problem, park officials blew up the moraine to make way for the Merced River. Fast forward a century and some change and we get the picture below.

(erosion)

That is a significant amount of erosion in a relatively short amount of time. It's interesting to have evidence of something we have changed for our convenience, to have it come back and bite us.

Since we now see that this is a problem, park officials want to restore the El Cap moraine and build it up to its original state. But here is the moral question: Is it better to restore the moraine and deal with floods? Or to not touch the moraine. Its an easier question without knowing that this park attracts around 4 million tourists annually, bringing in an insane amount of money.

I realize this isn't as directly hazard related as other posts, but I think it deals with the same relationship we find in other situations. Risk v. benefit. Oh and here's an ad that I am in for GPR equipment. Coming to a geophysics magazine near you!

I'm the third GPR professional from the left holding one of the
antennae. Credit to Harry Jol for the photography! 

Return from Yosemite/ Fire update

A few days ago I returned from my ten days out west. This was part of a special topics class where students from both the geography and English departments come together for a special trip designed to engage students in unfamiliar practices. For instance, part of the time spent out west was spent in San Francisco where we learned about beat poetry and its cultural influence in the 1950's. After five days on the coast, we headed inland to Yosemite. Here we conducted research on the El Cap moraine, and learned an incredible amount about the geologic history of Yosemite Valley. Looking back on it now while having hazards in my head, there were a couple very good examples of natural hazards. Enough for a couple posts about it! But before discussing any of that, I would like to post about the fire conditions, because that is the hot topic surrounding Yosemite. While in the visitor center, I snapped a few pictures of the fire maps which I'll show below. I might even have some charred Yosemite landscape pictures!

This is a simple map of the first status in Yosemite at September 21st. At the time having burned up over 250 thousand acres.