Part 2

The place that I originally wrote about was my backyard back home in Omaha, Nebraska. I wrote about how my backyard was where I spent a lot of time practicing soccer, playing with friends, and more. However, after I moved to Beijing in 2013, I started to miss that backyard a lot and I began to realize that I had taken green spaces for granted. In Beijing parks, you almost never see grass, and if you do, you are not allowed to be on it. In addition, the air pollution only made being outside worse, which made me miss those green spaces back in Omaha even more. Even though I missed my backyard a lot, I had a lot of questions about the space. For example, I wondered – why do we put so much effort and resources into making a lawn look nice? Why do grass lawns even exist in the first place? Although I think backyards are great spaces for recreation, I cannot help but think that they are not the best use of land or resources.

Thinking about this has also made me reflect more on Omaha and man-made environments as a whole. When my parents first moved to Omaha sometime around 1998, a significant portion of what are now suburban neighborhoods used to be cornfields. Long before that, there were Native American tribes living on the land, also farming corn. Without a doubt, humans have played a massive role in altering the landscapes and ecosystems of Nebraska, Omaha, and maybe my backyard, for hundreds and thousands of years. Even though the changes have been rapid, they pale in comparison to the changes that Earth has undergone in its billions of years of history.

Nebraska is not known for its natural scenery or geologic wonders. Since it is a part of the Great Plains, the land is relatively flat and unforested. If you ever drive through rural Nebraska, you will just see corn on all sides. Even though the landscape may seem boring, I am sure that its geological history is not. I know that at some point in Earth’s history, Nebraska was covered by seawater. If this was the case, then what kind of sediment would we find under Nebraska? I think it is likely that we would be able to find a layer of calcium carbonate left by the marine organisms that used it to produce shells. In fact, this reminds me of a field trip I went on when I was much younger. It was an outdoor site where we were free to dig, and the goal was to find fossils. At this small site, there was an abundance of ancient marine fossils and shells that I presume were left there when Nebraska used to be covered by ocean. I do not think I realized back then the geological significance of those fossils. However, now I realize that it is sound evidence that Nebraska was once under the sea and was likely much more tropical than it is nowadays.

Furthermore, I was doing some more reading about Nebraska’s geological history and it turns out that during the Pleistocene, a large portion of Nebraska was covered by glacial ice. I had no idea that this was the case, which makes me curious about the kind of evidence that I might be able to observe. Is it possible that I actually live on a drumlin? I suppose I could find out by digging down and seeing if the sediment is indeed glacial till. Also, I could look at topographic maps to observe the steepness and shape of possible drumlins. In addition, I could also find bedrock and see if there are any glacial striations or glacial polish that would show evidence of glacial ice movement over Nebraska.

Omaha also neighbors the Missouri River. In the section of the river next to Omaha, the Missouri is a meandering river. In fact, Omaha’s main airport is situated in between the point bar side of the meander and an oxbow lake. One thing that I was curious about when we were learning about rivers was how long sinuosity changes take. Over time, it seems like if the Missouri River continues to bend, the airport could be put in a costly situation. However, this all depends on how long it really takes for a river to change. One way I could attempt to observe this is by looking at historical maps and calculating the speed at which the river shifts.

I had always thought that Nebraska’s landscape was quite dull. However, I had never given much consideration to its geological history. The landscape today is a result of hundreds of years of human intervention and it is easy to forget that it used to be much different. I think it is intriguing that geologists are able to make such accurate observations about massive changes throughout Earth’s history, yet no human can live long enough to witness these changes. Even though we cannot see these changes as they occur, it does not mean that they are unimportant. The same can be said for our actions going forward. Even though we might not be seeing all the immediate effects of unchecked fossil fuel usage, pollution, and deforestation, the changes are sure to come. Personally, going forward I want to consider the geological history of whatever space I occupy. I want to understand the millions of years of geological processes that have led to my surrounding environment since it is important knowledge to have.

It is hard for me to imagine what kind of geological legacy humanity will leave behind. Will an advanced species millions of years into the future dig and find a layer of sediment laden with plastic particles? Will they be able to understand that a rapid rise in atmospheric carbon dioxide levels was caused by human use of fossil fuels? I think it is important that we, as humans, be conscious about how our actions contribute to a bigger, geological picture. Geology is such a powerful tool for building a stronger connection between humans and the Earth, and that is a belief I will carry with me wherever I go.


Kevin Zhang