Stephen Hill

Geology from the air

jenebauerLeave a comment

By Stephen Hill and Amanda Fischer. Stephen wrote the text and Amanda provided the images.

The geology you can see from an airplane is truly spectacular- the sights of the world below have enchanted most everyone who has taken an airplane. In this post, we walk you through the geology behind some of the sights you might see from the skies going across the western United States. Next time you take a flight, look out the window and learn more about the geology all around us! 

Most people are aware that there are volcanoes in the western United States (U.S.) thanks to the frequent headlines of some of the large strato-volcanoes (e.g., more cone-shaped volcanoes, like Mt. Saint Helens) in the Cascades of Washington and of course the “doomsday” headline-maker, the Yellowstone caldera or “super-volcano.” What many folks are not aware of are the many smaller volcanic fields that dot the South-Western U.S. including Arizona and New Mexico, even though they are often responsible for some of the iconic mesas and plateaus associated with those states. The 8,000 square mile (about the area of Vermont) Raton-Clayton Volcanic Field of New Mexico is one such example. 

The first occurrence of volcanism at the Raton-Clayton Volcanic Field in New Mexico is thought to have occurred around 50 million years ago and has had sporadic eruption events to as recent as 30,000 years ago. Image 1 was taken while flying over this volcanic field. Visible in the center of the frame is a textbook example of what geoscientists call a cinder cone (or scoria cone) volcano: this one in particular is called Capulin Volcano. Cinder cones are the most common type of intraplate volcano (i.e., a volcano not located on the boundary of a tectonic plate) and are formed when fountains of lava erupt from a volcanic vent. As the lava is ejected into the air, it cools into rock and ash and begins to collect around the vent. Over a period of constant or spaced-out eruptions, this accumulation will form the cone shape you see. Capulin represents some of the younger activity in the field, estimated to be 30,000 years old which is why it retains its textbook shape–– it hasn’t yet been weathered away, like some of the older features of the field.

View from airplane of topography and some meandering rivers of light-colored rocks. In center is a cone shaped volcano.
Image 1. Raton-Clayton Volcanic Field (New Mexico, USA). In the center is the cinder cone volcano, Capulin Volcano

The older a feature is, the more time it has spent exposed to the weathering processes of Earth’s surface; this can drastically alter the way some volcanic features look. If we look at Image 2, we can see an expanded view of Image 1. Now, a second cinder cone is visible at the bottom of the frame. In between the two cinder cones, we can see two features that look like squiggly outlines with flat tops. These are called mesas now, and they’ve been worn down over many, many years of weathering and erosion, primarily from wind and rain. 

View from airplane of topography and some meandering rivers of light-colored rocks. In lower left corner is a cone shaped volcano. A lot of the topography has been worn down from erosion, so features are flatter than they were when they would have formed
Image 2. Another view of Capulin Volcano (lower left) in the Raton-Clayton Volcanic Field, with mesas throughout, formed from weathering and erosion

Weathering and erosion are also responsible for some of the most spectacular aerial scenery you will see over the Western US (e.g., the Grand Canyon). Visible in Image 3 is Glen Canyon, which, just like the Grand Canyon, has been cut by the mighty waters of the Colorado River. The geology of this area is primarily dominated by sandstone (i.e., Navajo & Wingate sandstones) which have been eroded by the flow of the river over the course of millions of years. The meanders of the river are cut into the sandstones and leave traces of the river’s path from years gone by: this produces many spectacular views. Viewing erosive patterns from a bird’s eye view can also help inquisitive minds better understand runoff and the creation of rivers/watersheds, as seen in Image 4.

Canyon- features formed from a river- evidence of the river is currently still there, winding around and evidence of where the river was years ago is, too, as evidenced by the rock patterns where water cut into them
Image 3. Glen Canyon, formed by water of the Colorado River
patterns of water run off cut into rocks from a bird’s eye view: water ran down the tops of higher topographic features and cut into them, leaving behind patterns of how the water moved down it.
Image 4. Patterns of erosion from wind and water movement leave behind these gorgeous views that we can appreciate from above

Misconceptions of Evolution

jenebauerLeave a comment

Alyssa Anderson, Aaron Avery, and Stephen Hill
*All authors contributed equally 

As humanity embarks into the twenty-first century, the importance of understanding the theory of evolution has never been greater. This importance is not rested solely in understanding human existence, but on the natural world as a whole. If humanity hopes to tackle such issues as curing cancer, fighting antibiotic resistant bacteria, and finding crops better adapted to global climate change, then we must impart a broad understanding of the theory of evolution to the next generation. Misconceptions in the understanding of evolution are a common occurrence and can be difficult to approach in the classroom, but because of the importance of this issue the scientists and educators of today should be well versed in how to teach evolution in both a confident and equitable manner that does not foster resentment from their students. This article seeks to address some of the more common misconceptions and supply responses to them, for educators and for evolution learners

1) Evolution is a theory, not a law

This misconception stems from a mix-up between casual and scientific use of the word theory. In everyday language, theory is often used to mean a hunch with little evidential support. Scientific theories, on the other hand, are broad explanations for a wide range of phenomena. In order to be accepted by the scientific community, a theory must be strongly supported by many different lines of evidence. Evolution is a well-supported and broadly accepted scientific theory; it is not ‘just’ a hunch. Evolution is a theory and it is also a fact- meaning that it is extremely well supported in scientific studies. 

2) Evolution goes against religious beliefs

Accepting religion does not discredit evolution and science, and vice versa. Many may believe that science is inherently atheist or agnostic, or that science requires one to forgo their faith entirely. Not true! Evolution is a means to explain an unknown phenomenon in the world by using what we can test in the world around us; in this case, evidence that shows organisms changing over time. It’s the same way people use science to understand nature today, such as answering why the sky is blue instead of only wondering. Religion seeks to explain phenomena outside of nature. But understanding how nature works does not discredit faith! The goal of scientific theory and explanation is not to prove something wrong, it simply seeks to understand by testing naturally occurring phenomena around us. 

3) Evolution doesn’t explain the origin of life 

Evolutionary theory discusses ideas and evidence surrounding the idea of the origin of life, but this is not central to what evolutionary studies aim to learn. Evolution describes the processes involved in life changing over time, not how it started. Evolution considers factors such as adaptation, mutation, and natural selection as mechanisms for driving biotic change throughout Earth’s history. Random (mutation) and non-random (selection) processes contribute to evolutionary change. The idea that the study of evolution seeks to understand how life changed after it started gives us an advantage when teaching science to students who may have differing opinions on how life appeared on this planet. Science and religion are not at odds as they each seek to answer fundamentally different questions in fundamentally different ways. Science and religion in this way do not have to be diametrically opposed, and therefore we are able to discuss the principles of evolution without engaging in dialogue refuting any particular belief system on creation.

4) Evolution is Slow and Gradual

Evolution occurs at many different rates. Yes, it is a gradual process that is constantly taking place over millennia. However, it can also be a rapid process, geologically speaking. One thing to remember that is always hard to fathom, is just the sheer massive scale of time being discussed whenever talking about evolution on geologic time scales. When we see “rapid” evolutionary change, it is often rapid relative to longer time scale phenomena. However, rapid geologically often means hundreds of thousands or even millions of years. We find evidence for this in the fossil record. The Cambrian Explosion is one such example. This was a time period of exceptional adaptive radiation that resulted in a figurative “explosion” in the number and type of organisms we find in the geologic record. This “explosion” should be considered relative to what we see in the fossil record during other time periods. This never indicates a sudden rise of a brand new species from an existing one, as if a chicken laid an egg that hatched an eagle.

However, we do observe instances of rapid evolution going on around us all of the time. The most prescient example of this would be microbes, like bacteria, developing resistances to antibiotics in very short time frames. There have also been experiments conducted watching bacterial colonies respond to toxins that show they are able to adapt to deal with an environment that includes the toxins in only a few bacterial generations! Additionally, most of us can simply look into our backyards to find some species (even squirrels) that have developed adaptations to climate change over only a few decades. One example would be that red squirrels have been observed to have changed their breeding habits to adapt to warmer temperatures earlier in the year as the climate has warmed progressively. 

5) Organisms aren’t always optimally adapted

Good enough is fine! Organisms do not need to achieve perfection, and it is not a race to climb up the ladder. They just need to be ‘fit’ enough to survive and reproduce (in fact, fitness truly refers to the number of offspring one has: the more offspring, the higher fitness). Also, ‘fitness’ depends on the environment. When the environment changes, a fit organism’s adaptation may become less successful (thus, the organism may no longer be adapted to the environment).

6) The goal of evolution is always to improve organisms

Evolution never “seeks” a specific goal. Evolution doesn’t have conscious thought; no matter how wonderfully complex nature may seem, it can’t force progress and can’t make decisions. Natural selection works on a scale of “more likely”—when random processes such as mutation and genetic drift occur, it can make organisms more likely to survive, but it’s not a guarantee. Most genetic shifts are minor or benign anyways, and don’t even result in what we may perceive as progress within single generations. Evolution is not a race, and there’s certainly no finish line to create the perfect organism! Evolution (much like a jedi) simply doesn’t deal in absolutes. 

It is important to remember that when a student or individual brings up a misconception about evolution, it is not okay to alienate or ridicule them. It is often the case that this could be a person’s first time encountering this concept and their background or upbringing could make this a difficult subject to approach. By embarrassing or making someone feel alienated, a person will often not want to learn more on the subject. Above all, be respectful and help people learn about the amazing world around us!