Scientist of the Week

Sarah here-

I took a geoscience education class as an elective my senior year of college. One of our first assignments was to draw a picture of a scientist. That was all the direction we received from the professor. And yet, even with this vague assignment, all of the students (yes, including me) drew the exact same thing: a white man with messy hair and a lab coat. Why?

Science has had a long history of discrimination and exclusion. This shouldn’t be a surprise: since science is done by humans, and humans have shaped how we view scientists through centuries. Because of this, many of us have shaped in our minds the image of a scientist- the one I described above. And that’s something I want to change.

My geology classes are primarily taken by introductory students-I teach hundreds of students every year, from every conceivable life experience. And many of these scientists that we talk about in class-Charles Darwin, Charles Lyell, James Hutton, Alfred Wegener- look very similar. And while all of these scientists made incredible contributions to science, we often overlook equally incredible contributions by scientists that didn’t fit the mold of the ‘typical’ scientist. I wanted to change that. So, in my classes, we started a “Scientist of the Week” segment to highlight the achievements of all kinds of scientists. I began making a list for myself- this list started with the scientists that I have heard of- famous scientists that lived long ago or scientists that I’ve read about recently and even scientists just starting out their careers. My list was subdivided into many categories-women in STEM, Native/Indigenous in STEM, Black in STEM, military veterans in STEM, Deaf/hard of hearing in STEM, LGBTQ+ in STEM, etc. So far, I have over one hundred scientists on my list and I’m adding more daily.

This is an image of Dr. Wangari Maathai (Photo Credit: Patrick Wallet), one of our past scientists (and one of my personal heroes) of the week. Dr. Maathai was born and raised in Kenya; in the 1970s, she became the first woman from east and central Africa to earn a PhD. She is the founder of the “Green Belt Movement”, which paid women in Kenya to plant trees. This program had extreme success, both at lifting vulnerable populations of women out of poverty and at rebuilding forests across her country. She had so much success in this project, that it was modeled in other nations. She was awarded the Nobel Peace Prize for her work in 2004, becoming the first African woman to win the Nobel Peace Prize and she remains one of the only environmentalists to have won this prestigious award. To learn more about Dr. Maathai’s work, read this biography.
I show a photo of the scientist to my students and tell them a little bit about their story during lecture and provide a written blurb of their achievements for my students to read later. One of our recent scientists was Dr. Wanda Diaz-Merced, an astronomer from Puerto Rico (who now works in South Africa). She lost her eyesight during her undergraduate education; after she lost her sight, she developed programs to transfer her data into audible sound so that she could continue to analyze her research in a method that best suited her. Another recent example was a friend of mine, Dr. Rene Shroat-Lewis, who is a paleontologist. She is also a veteran and served in the US Navy-she gave good advice to veterans returning to college on how to find their future path. Many of the scientists I highlight, I also highlight how discrimination shaped their experiences in the sciences and how discrimination has shaped how some of these scientists are remembered in history. For example, we recently talked about Rosalind Franklin, the scientist who took the first image of DNA’s structure. Her work was famously shown to James Watson and Francis Crick, who used her data to finish their analysis of DNA. They later collected the Nobel Prize for their work, while Franklin’s work was left largely ignored. James Watson later wrote in an autobiography about Franklin, insinuating she wasn’t bright enough to understand her scientific data. James Watson has been recently featured in the news for asserting racist views. My class and I discussed how the science community for many decades chose to ignore Watson’s racism and sexism, to the detriment of the career’s and safety of traditionally discriminated groups of people in science.

I want to share these stories because they mirror the experiences of many of my students. My university, The University of South Florida, serves a broad diversity of students. I want students to see scientists that share their backgrounds-science doesn’t belong to men, to able-bodied people, to white people, to heterosexual people, to cis people, to people with Phds., to any religion or lack of religion, or to any economic class. Science belongs to everyone. However, I don’t feel that it is right to only highlight the awesome stories of scientists in underrepresented groups without also highlighting how discriminatory attitudes have shaped our history of science. Scientists must reflect on this history to always make sure that we are working towards building an inclusive community.

I have only been doing this for a few months, so I haven’t been able to compile data on how my students are engaging with the material. I have had a few students tell me their feelings, so I do have some anecdotal evidence. One student told me that she felt more confident to apply to medical school, after seeing scientists that looked like her and shared many of her experiences. Another student told me she had never seen a Native scientist highlighted in a classroom before-she sent the Scientist of the Week to members of her community and started learning about other Native scientists. I’m not naïve enough to believe that this Scientist of the Week exercise is enough to “fix” the significant challenges the science community faces in terms of diversity and inclusion. Changing the science community to reflect the diversity we have in the world will require much more work. But this is an effective way to introduce large groups of students to a history of science that isn’t nearly as often told.

If you’re interested in doing a similar project with your classes or if you have suggestions for scientists to highlight (self-nominations encouraged!), come talk to me! You can find me on twitter @sarahlsheffield

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I’m just bad at science

Sarah here-

If I had a dime for every time I heard this sentence…well, let’s just say I’d probably be free of student loans by this point! I teach hundreds of introductory geology and the large majority (95% or so) are not science majors. So, suffice to say, I teach students with a range in interest and self-assumed ability in science. But after three semesters of teaching full time and nearly 1,000 students, I’m putting a ban on this phrase in my classes and I’ll tell you why.

I want to talk about what it does to your ability to learn when you come into a classroom with the idea that you’re bad at something. You come in with a mental block that will stay with you for the duration of the class. If you struggle with the material, you’ll only give yourself a confirmation bias (see? I don’t get this stuff. I must be bad at science/math/French/whatever it is). How are you supposed to learn with that attitude? You can’t! And before you say “it’s easy for you to say-you’re a scientist with a Ph.D. You weren’t bad at science”. This simply isn’t true.

I found this ad in an Astronomy magazine when I was in college. I saved so that I could look at it and remind myself to expand what I can do and not tell myself what I can’t do (this ad was for Shell (JWT London) from the 2000s).
I struggled with learning math and science through middle school, high school, and through college. I’d sit down to study-I’d feel overwhelmed instantly. I’d tell myself “you’re not good at this stuff” so much that no matter how hard I’d study, I’d second guess myself on just about every problem, leading to even worse self esteem (and not surprisingly, worse grades on assignments). By the time I got to classes like Calculus and Physics in college, I had only made this even worse for myself. I told my professors when I went for help “I’m bad at math” or “I’m bad at chemistry”. Finally, a professor looked at me in my final math class (Calculus II) and said, “Sarah, you know you’re actually quite good at math. You just need to give yourself a little more time to learn it. And you need to be kind to yourself”. That idea stayed with me for a very long time- it freed me to be patient with myself. And to let me love learning without the fear of grades a little bit more. I made my highest grade on a college math exam that semester (a B-!) and you know what-I was (and still am) proud of myself for that exam grade-I even hung it on my apartment fridge for the entire rest of the semester so I could celebrate it every day. Achievement isn’t always measured by A’s!

Many of us (myself included) automatically assume that what we’re good at and what comes easily to us is one in the same. On the flip side, we assume that we’re bad at things we’re not automatically good at, especially in the world of academics. This simply isn’t true. To take an easy example, one that you’re familiar with if you’re reading this blog, is learning to read. Learning to read is incredibly complex! It took you months to years just to master your alphabet- learning to recognize each individual letter. Then, it took you even longer to figure out how to string bizarre patterns of these letters together to form words, sentences, and paragraphs. No became good at reading overnight-it’s a skill that you worked on for years. And, just like reading, none of us were born to learn science instantly! It takes time to learn how to learn science, just like you learn anything else.

So how can you boost your confidence in science? I’m glad you asked! If you’re taking a high school or college course, ask for help. Visit your professors and ask them to help you! We can explain concepts to you in different ways, help you relate the knowledge to something you’re more familiar with, or just assure you that you’re on the right track. Many times, my students have asked questions that have forced me to learn how to make a concept clearer (so professors actually really appreciate it when you tell us what you’re struggling with). Also, seek out cool articles or blogs or even popular science books in the subject you’re learning about! It can really help to boost your enthusiasm about a concept, which can help your confidence, too.

So give yourself permission to be patient with yourself. Science may not come easily you to-it’s never come easily to me. I worked hard to pass chemistry and even geology classes (looking at you, structure and tectonics!). It’s OK to love something that takes you more time to learn. And it’s also OK to pick a major or to take classes in something that you might need a little more help with. Science is a wide and complex field that takes dedication to master. It can take years to learn how to learn science to the point where you feel confident enough to proclaim, “I’m good at science!”- so why do so many of us automatically label ourselves bad at science? Just like learning to read, learning science isn’t easy! It takes time!

So here’s my warning to my students starting this semester-I’m no longer going to let you say that you’re bad at science in my class (and I don’t want to hear it from people reading this blog, either!). Your science education is a work in progress- and we’re going to work together to help you love science.

Revising echinoderm relationships based on new fossil interpretations

A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa, Echinodermata) and its bearing on the evolution of early crinoids

by: Sarah L. Sheffield and Colin D. Sumrall
Summarized by Sarah Sheffield

What data were used? New echinoderm fossils found in Oklahoma, USA, along with other fossil species of echinoderms. The new fossils had unusual features preserved.

Methods: This study used an evolutionary (phylogenetic) analysis of a range of echinoderm species, to determine evolutionary relationships of large groups of echinoderms.

The arms of Eumorphocystis. A. This is an up close image of the arms that branch off the body. B. The arms of Eumorphocystis have three separate pieces comprising them: these three pieces are highlighted in yellow, blue, and green. This arm structure is nearly identical to early crinoid arms, indicating that crinoids might be more closely related to creatures like Eumorphocystis than we previously thought.
Results: Eumorphocystis is a fossil echinoderm (the group that contains sea stars) that belongs to the Blastozoa group within Echinodermata. However, it has unusual features that make it unlike any other known blastozoan: it has arms that extend off of the body, which is something we see in another group of echinoderms, called crinoids. Further, these arms have a very similar type of arrangement to the crinoids: the arms have three distinct pieces to them (see figure). Researchers placed data concerning the features of these arms, and the rest of the fossils’ features, into computer programs and determined likely evolutionary relationships from the data. The results indicate that Eumorphocystis is closely related to crinoids and could indicate that crinoids share common ancestry with blastozoans.

Why is this study important? This study indicates that our understanding of the big relationships within Echinodermata need to be revised. Without an accurate understanding of these evolutionary relationships, we can’t begin to understand how these organisms actually changed through time-what patterns they showed moving across the world, how these organisms responded to climate change through time, or even why these organisms eventually went extinct.

The big picture: This study shows that crinoids could actually belong within Blastozoa, which could change a lot of what we currently understand about the echinoderm tree of life. Overall, this study could help us understand how different body plan evolved in Echinodermata and how these large groups within Echinodermata are actually related to one another. Data from this study can be used in the future to start to understand evolutionary trends in echinoderms.

Citation: Sheffield, S.L., Sumrall, C.D., 2018, A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa, Echinodermata) and its bearing on the evolution of early crinoids: Palaeontology, p. 1-11. https://doi.org/10.1111/pala.12396

To read more about Diploporitans please click here to read a recent post by Sarah on Palaeontology[online].

Bathroom Geology

Do you ever see pictures of beautiful geology all over the world and think “WOW, I don’t think I’ll ever be able to see that in person”? Well, think again. This post is dedicated to helping you find amazing geological finds in a place I can guarantee you will visit just about every day: the bathroom (and no, I’m not just talking about coprolites)!

The goal of this post is to teach you a little about the types of rocks you might see the next time you’re in a restaurant bathroom, a bathroom at the beach, the library bathroom, or even the bathroom in your own house! You might be thinking “oh, but what can I learn from a bathroom?!” Well, you just might be surprised. So, let’s get to learning!

Figure 1. A granite countertop from a restaurant in Richmond, Virginia. This granite is unique because of the concentric zoning of the crystals- this means that the crystals were cooling at slightly different temperatures, giving it the unusual appearance of the larger crystals (where my finger is pointing). Different elements are crystallizing out of the magma at different temperatures, which gives it this look of almost like tree rings.

Our first stop is a small restaurant in Richmond, Virginia. The food was good, but the real treat was finding the granite countertops inside the bathroom (Figure 1)! Take a look! Granite is an intrusive igneous rock: meaning, the magma from which the rock was made cooled slowly underground. We know this because of the very large crystals that we can see! Crystals grow from the liquid magma; the longer they take to cool, the larger they grow. Now, let’s look more closely at these big crystals. If you look at the large, light pink colored crystals where my finger is pointing you might see that they are what we call “zoned”- meaning, there are alternating circles of slightly different colors inside the crystals- their rounded shape means we’d assign the term “concentric zoning” to them. This actually tells us something really cool about their cooling temperature!

Figure 2. Bowen’s Reaction Series explains the pattern of what minerals and elements cool at what temperatures. As magma cools, certain materials are always crystallized first and pulled out of the pool of magma. Photo credit: National Parks Service

Magma cools at different rates- depending on where it is on Earth or the types of materials from which the magma is made. This rate of cooling determines how and when certain minerals form, or crystallize. In other words, geologists know quite well at what temperature a mineral will form within a magma chamber as it cools down. This predictable pattern of mineral formation with cooling temperatures is called Bowen’s Reaction Series (Figure 2). When this happens, it means the chemistry of the still-liquid magma changes quite a bit!
To put this into a more delicious and more relatable example, think about a giant jar of Starburst-with red, pink, yellow, and orange evenly mixed in. Let’s say you give this jar to me (I really love Starburst). I will preferentially eat all of the orange ones out of it; then the pink; then the red; and finally, we’ll only be left with yellow (gross, who eats the yellow ones?!). We’ve changed the overall composition of the magma (i.e., the jar of Starburst) by preferentially pulling out one type of material in a specific pattern. Now, take a look at the giant crystal my finger is pointing to- the zoning is going back and forth between a sodium and a calcium rich solution in the feldspar (the name of the mineral)-this indicates that the temperature of the magma where this was cooling was changing slightly, alternating between a little hotter and a little cooler.

Figure 3. This granite has almandine garnet as an accessory mineral, which means that the magma from which it formed had a lot of aluminum in it!

Now granite is really cool and it’s a very common bathroom countertop, so let’s look at another example (Figure 3)! This granite was part of a larger piece of rock that was installed in a private home bathroom in Fayetteville, North Carolina. This little piece was leftover, so the countertop store let me have it! This granite is similar to the granite from above, but it doesn’t have any zoning, meaning it all cooled without any weird changes in temperature. However, it does have one pretty cool feature-the garnets! These garnets (the little red crystals) are of the almandine variety. Almandine is a type of garnet that has a lot of iron and aluminum in it. Garnet forms in granite as an accessory mineral (meaning, not a major component) and different garnets can mean different things. In this particular sample, this almandine garnet means the magma was aluminous; meaning, there was a lot of aluminum in this magma!

Figure 4. This migmatite formed from the combination of an igneous and a metamorphic rock; this rock also has ptygmatic folding, which is seen in the lighter layers as the squiggles running across the rock. These form from high temperature and pressure and from one of the rocks being much more viscous than the other (in this case, the lighter rock is much more viscous than the darker rock- much like honey is more viscous than water).

I found this gem at a women’s bathroom in the San Francisco airport (SFX) last year (Figure 4)! This rock is called a migmatite. A migmatite is unique in that it is a cross between an igneous (formed directly from cooled magma or lava) and a metamorphic rock (a rock that was exposed to heat and pressure after its original formation). The dark and the light material you see here are from two totally different processes. The light material here is mostly quartz (the same mineral that we call amethyst or rose quartz–quartz occurs in a variety of colors). The lighter material is much more viscous-meaning, it resists flowing (like honey or molasses), while the darker stuff (primarily from minerals called pyroxene or hornblende) has a lower viscosity and flows more easily. Now, do you see how the light colored material exhibits small and irregular folds? These folds are what geologists call “ptygmatic”. These ptygmatic folds generally occur at pretty high temperatures and pressure; these variables cause the layers to fold and buckle the way that they do because of the differences in viscosity. The high temperature and pressure, along with the high viscosity of the light material, will cause these types of folds to form (these are also known as “passive folds”).

Figure 5. Internal and external molds of fossils at the St. Petersburg beach bathroom! These form when the actual shell of a creature is worn away and all that is left is the mud that either filled the inside of the shell or the mud that formed around the shell.

I recently saw this one (Figure 5) at the St. Petersburg beach in Florida, pretty close to where I live. These blocks are part of the public bathroom walls and as you can see, these bathroom walls are chock full of fossils! Wow! These fossils are from Florida and they’re pretty recent–no more than 10-20 million years old. They’re also primarily mollusks, the large group that contains octopuses, clams, snails, and oysters. Imaged here are snail fossils-you can identify these snails by their long, delicate shells- and clam fossils-you can identify those by the much larger shells that have ridges along the edges. These types of fossils are called “molds”-this means that the shell itself has been worn away and all that’s left is the sediment that either filled in the shell or the sediment that formed around the shell. The internal molds are where you can see an actual 3D shape of the inside of the shell, whereas the external molds are where you only see an impression of the shell.

Figure 6. Labrodorite is a type of feldspar that has an easy to recognize iridescent sheen. Labrodorite is most commonly found in mafic igneous rocks, like basalt!

Last but not least, my mom snapped this picture of her bathroom just for this post (thanks, Mom!)! Labradorite is a beautiful mineral-it’s a type of feldspar, which is in the same group as the lovely pink minerals seen in the granite in Figure 1. What makes labradorite so different, though, is that this feldspar doesn’t form in granite-it forms in a very different type of rock, like basalt! Basalt is an extrusive igneous rocks, so it forms from lava that cools at the Earth’s surface. Basalt is found in places like Hawaii, where it comes out of volcanoes, or at mid-ocean ridges, where new seafloor is being made. Basalt is mafic, meaning that it is full of heavy minerals like iron and magnesium. Labradorite is famous for its iridescent sheen-you can see it here in Figure 6!

I hope that this post has shown you that you don’t need to travel to fancy and far away locations to see real and beautiful geology up close. Sometimes, interesting geology can be as close as the nearest bathroom! Next time you see one of these counters, stop and take a look! What do you see? Do you see fossils? Garnets? Zoning? Do you see something entirely different? Before I go, I’d like to thank geologists Cameron Hughes, Zachary Atlas, Elisabeth Gallant, and Jeffery Ryan for help with identifying some of the details in these rock samples!

The Bay of Fundy, Part 2

High tide at the Sea Caves in St. Martin, New Brunswick. Far out in the distance are quite large caves, but you can’t see them due to the high tide!

This is the final post in the series of the geology of Maine and the Bay of Fundy. To recap for those of you who might not have read my first post, I documented all the geology I saw recently on a vacation my husband and I took to Maine and New Brunswick, Canada. This is the second post all about the geology of the Bay of Fundy! This one, though, will talk about the famous rocks of the bay and how they got the unusual shapes that made them famous. Remember, the Bay of Fundy is famous because it has the highest tides on Earth.

Scenic photo of an overlook at the Fundy National Parkway

So what do these tides do to the rocks? To answer this, let’s first go to St. Martin, to the famous Sea Caves. You might be looking at this first image and think “what caves!”? Well, this first image is taken at high tide, so the caves are almost entirely underwater. High and low tide were separated by about six hours, so we saw high tide, admired the lovely scenery, and drove to see the Fundy Trail Parkway, a park that you can drive or hike the entire way through for some GORGEOUS scenery. There are spots to pull over and get out, hike short distances, or just look out from a cliff to see some beautiful sites. Here’s a picture overlooking the Bay of Fundy – remember, these lovely coastlines were largely created by the formation, movement, and melting of glaciers.

Low tide at the Sea Caves in St. Martin. This is taken at the same distance from the caves as the image from high tide.

We returned to the Sea Caves to see it at low tide-take a look! This picture is from the SAME spot, give or take a few feet. This photo should show you the height and amount of water moved by tides every day in the Bay of Fundy. The presence of these caves is due to mechanical weathering-literally, the waves associated with the tides coming in and out are quite strong and they break down the rocks. Thousands of years of these waves have created immense caves and crevasses. Once you are able to walk across the seafloor at low tide, you can truly appreciate just how incredibly large these caves are and just how strong the tides are! Here’s an image of me inside one of the caves!

I’m standing at the very back of one of these sea caves!
As we walk across the seafloor, you can see how large these cave systems really are-they’ve been created by thousands of years of strong wave action, something we call mechanical weathering.

There’s one last thing I want to point out about these tides-the effect that they have on living creatures! Snails and barnacles live in high abundance all over the area affected by low tide and these creatures find incredible ways to survive when the low tide means that they aren’t covered by water! Snails will gather in small cracks in rocks where water will pool; barnacles will form more in shadier areas, so the rocks will remain more damp than those exposed to the sun. Sometimes, snails will hang on to a piece of algae just to survive until the water comes back! Check out this image of a snail holding on for dear life!

Snails have methods to survive low tide-this snail is clinging to a piece of algae to survive until the water comes back into the area. This picture makes me think of Jurassic Park and the famous line “Life, uh, finds a way”

Now, let’s travel north to Hopewell Park, where the most famous rocks from the Bay of Fundy are. First, let’s look at the difference between low and high tide. These images are taken just about 4 hours apart. So the rock you see here was broken off from the cliffs due to chemical weathering-water percolating through cracks and breaking them apart. But, the odd shape that you see now, where the rock is much narrower on the bottom-that’s due to mechanical weathering. Wave action over thousands of years has caused these shapes to form. These rocks CAN fall without warning (and have, even recently), so park rangers are always making sure to look for signs of instability.

Low tide at Hopewell Rocks. These rocks are HUGE!

To really experience high tide, my husband and I signed up to kayak through these rocks. To say that the waves here were strong is an understatement! The waves were cresting at just under 4ft-so imagine sitting down on the beach front-you’d be completely covered (if you were curious, kayaking in 4ft waves and high winds was a blast, but also a little terrifying!)! Here’s an up close picture of that same rock you saw in the previous two pictures, from the kayak! Now you can really see where the rock is narrowed at the base-the line between the narrow and wider part of the rock marks the highest the tides can go.

High tide at Hopewell Rocks. Park rangers have to close this off quickly when the tide starts coming back in, to prevent people from being swept in the strong waves.

I hope you’ve enjoyed this series! I think one of the most important things I can say here is that this trip made me rediscover my love of geology. Sometimes, when you work long hours every day as a geologist, it can become a little hard to remember just why you love it. If you’re feeling that way, I encourage you to get out and go explore for a little while- a few hours, or even a few months, if you can!

An image of the rocks from the kayak at high tide. Take a look at how wave action has shaped this rock, from how it narrows at the base and has a large crack in the center.

New plesiosaur fossils from Antarctica

The first non-aristonectine elasmosaurid (Sauropterygia; Plesiosauria) cranial material from Antarctica: New data on the evolution of the elasmosaurid basicranium and palate

 O’Gorman, J.P., Coria, R.A., Reguero, M., Santillana, S., Mörs, T., Cárdenas, M.
Summarized by Sarah Sheffield

What data were used?

New fossil material from Vega Island in Antarctica

Methods

The fossils were prepared using tools like a jackhammer to remove the fossils from surrounding rock. The fossils were then measured using digital calipers.

Results

Rare fossil material recently found from Vega Island in Antarctica shed light on the evolutionary relationships of extinct reptiles, the plesiosaurs. While a lot of plesiosaur material has been found in the past in Antarctica, this particular field study turned up skull material, which is quite rare! The skull material preserved multiple features that allowed researchers to better understand the evolutionary relationships between different groups of plesiosaurs. Specifically, features of the palate in the skull, has features that link it to other groups of plesiosaurs, the elasmosaurids.

A representative of the specimen uncovered from Vega Island. Shaded in gray are the bones uncovered, including a rare example of a bone from the skull, preserving the palate of the plesiosaur!

Why is this study important?

This study is important for many reasons! First, it described very rarely preserved parts of the body (namely, the skull), which preserves a ton of information about its evolutionary origins. Second, Antarctica remains very unexplored for fossils; it is very expensive and difficult to travel and do field work in this part of the world. This means that with every new fossil find, our knowledge of the past history of Antarctica grows tremendously!

The big picture

New fossils from Antarctica provide new information concerning the biodiversity and evolutionary relationships of plesiosaurs from the Cretaceous. As Antarctica remains fairly unexplored for fossils, any new fossil finds contribute greatly to our knowledge of the history of the continent.

Citation

O’Gorman, J.P., Coria, R.A., Reguero, M., Santillana, S., 2017, The first non-aristonectine elasmosaurid (Sauropterygia; Plesiosauria) cranial material from Antarctica: New data on the evolution of the elasmosaurid basicranium and palate: Cretaceous Research, v. 89, p. 248-263, doi: 10.1016/j.cretres.2018.03.013

Geology of the Bay of Fundy

Sarah here –

Map of the Bay of Fundy. The reason why the tides are so high is because the bay gets very narrow, so all of the water going into the bay has to go vertically. Image from Bay of Fundy Tourism.
This post is a continuation of my first post, the geology of Acadia National Park. To recap for those of you who might not have read my first post, I documented all the geology I saw recently on a vacation my husband and I took to Maine and New Brunswick, Canada. This post will be all about the geology of the Bay of Fundy! Specifically, this will be about how glaciers have shaped the geology of the area.

The Bay of Fundy is an incredibly famous geologic area for a good reason-it has the highest tides on Earth, with the highest reaching nearly 56ft! The reason why the tides are so high here has to deal with the shape of the bay-the bay narrows quite a bit (as you can see from the map), so as all the water enters the bay, it’s forced to stack up on top of each other, making the tides reach these incredible heights.

The wave energy at this part of the Bay of Fundy is very high. We can tell because the sediment there is almost entirely very large rocks, as opposed to sand!
Glaciers have shaped a lot of the geology along the Bay of Fundy; as glaciers advance and retreat, they leave telltale signs. One of the best signs are when you see rocks called tillites. These rocks are made of glacial sediment. They’re fairly easy to recognize-often, you’ll see rocks with very large, poorly sorted clasts (meaning, all kinds of different sizes of sediment). These are left behind by glaciers! Here is an example of tillite along the coast of the Bay of Fundy. Look at all of the different sizes of clasts in there! This rock was found at the Irving Nature Center, St. John, New Brunswick. The wave energy in this particular area is very high, which you can tell by the lack of small sand grains and the prevalence of much larger clasts (pebbles-boulders). Another sign of glacial activity is the presence of striations on rocks. Striations are scratches in rocks that are caused by glacial ice moving over them. These glaciers can have lots of rock and sand debris within it, so as they move over rocks, it can cause a lot of surface damage to the rock. Check out this picture of striations on volcanic rocks, also from the Irving Nature Park!

Striations caused from glaciers scraping across a rock surface
Arguably, the most famous area of the Bay of Fundy is the site called Hopewell Rocks. I’ll discuss a lot more about the Hopewell Rocks in my final post, but for now, let’s talk about how glaciers shaped these famous rocks. As glaciers last retreated from these areas (meaning, the Earth warmed and glacial ice melted), the water from the glaciers filled into the ground and caused cracks to form along the coast. This is called chemical weathering. Water is a chemical and it’s the most common chemical that rocks come into contact with when we’re talking about chemical weathering. These cracks eventually caused these large rocks to be separated from the cliff line. This phenomenon might be more familiar to you when you’re driving- when roads (in colder areas, especially) have small cracks in them and water gets into those small cracks, that water can freeze, causing the crack to expand. After multiple rounds of freezing and melting, these cracks become a real problem to drivers!

Glacial melting caused the rocks along parts of the Bay of Fundy to crack (due to chemical weathering) and break off. Here’s a photo of some of these rocks at the famous Hopewell Rock site!
During our next (and final) piece about my trip through the Bay of Fundy, we’ll look at how these famous rocks are shaped by mechanical weathering, instead of chemical!

This rock, called a conglomerate because of the multiple large clasts within it, is indicative of a glacial environment.

Acadia National Park Geology

Sarah here –

My husband, Joe, and I at Acadia National Park!
I recently went on a trip with my husband to Maine, USA and New Brunswick, Canada to see some of the best geology these places had to offer! I’ll be showing you a lot of the gorgeous geology (and some cool biology!) through a series of posts. This first post will be all about my trip to Acadia National Park. My husband and I hiked quite a few trails (about 20 miles of trails total!) in the four days we were there and we learned quite a lot about the geology of the park from our adventures.

Here I am climbing the Beehive Trail, a famous trail in Acadia. It follows a path up and down a mountain composed of granite.
A lot of the rock you’ll see in the popular parts of Acadia- especially the trails in the main part of the park-will be granite. Granite is an igneous rock that formed intrusively, meaning, it formed under the surface of Earth. You can generally tell whether igneous rocks formed intrusively or extrusively (on Earth’s surface), because the sizes of the grains will be different. The magma that makes up granite cools very slowly under the surface of Earth-the slower it cools, the larger the crystals are! But, I digress. Many of the mountains in the Acadian region are made of granite. This granite was formed when two continents- Laurentia (North America) and Avalonia (eastern North America and western Great Britain) slammed together hundreds of millions of years together. When they collided, it forced a huge amount of magma to pool, creating the famous granite we see today (you can read a lot more about the creation of Acadian rocks at this site)! Here’s a photo of me climbing some of this granite on the Beehive Trail! The mountain is very steep and the trails are very narrow, so it is most safely climbed using metal ladders!

View from the summit of Beehive Trail. Gorgeous!
Granite is a very hard, stable rock. What that means is that it doesn’t weather away easily, like other rocks (think of how marble gravestones look like after a few decades-marble is much more easily worn down!) But after millions of years, even the toughest of rocks can start to be broken down! Take a look at these rocks here-you can see the cracks from being weathered (likely by rain!)-these cracks allow rain to penetrate into the rock and break it down even faster! To put it into perspective, think of a windshield-if you put a single crack into it, you’ve weakened the glass and further pressure can result in faster spreading of the break. Rocks respond similarly after the first cracks are formed!

Schoodic Point. This gorgeous part of Acadia is shaped by a dramatic coastline, formed by granite and altered by darker volcanic rock intrusions
I want to show you some of the cool pictures from the other side of Acadia now. This is a lesser known, but just as beautiful part of the park as the most well known part of Acadia. This area is called Schoodic Point. This is also dominated by the same gorgeous granite-but it’s got something else going on that’s really spectacular. If you take a look, you’ll see the gorgeous light colored granite…but also, intrusions of a dark colored igneous rock (called a diabase); this diabase has tiny crystals-meaning, it cooled quickly! We can tell that the dark colored rock intruded into the granite because of the Principle of Cross Cutting Relationships; this geologic principle means that if a rock “cuts across” another rock, the rock that is cutting across is younger (read more about geologic principles here).

An up-close look at just one of the diabase intrusions-some are massive! Some are much smaller.
So, with that in mind, these diabase intrusions are the remnants of later episodes of volcanic activity. There are multiple episodes of volcanic activity represented here-many of the intrusions are cut by even more intrusions! What a beautiful place. So even though this is a post about geology, I wanted to show you a little bit of the life here at Schoodic Point-the wave activity at this area is VERY high (one easy way to see that is that there’s very little sand at this coast-the wave energy is too high, so the sand gets washed away). The water crashes up onto the granite and some water will stay up there, giving a perfect spot for lots of little critters to form a home! Take a look at this small pool of water-how many critters can you see?

Here’s some of the life living on the rocks-the water is washed up from the waves and lots of critters will settle in here. Can you see barnacles, bivalves, snails, tiny crabs, and algae? Anything else?

Stay tuned for more posts on the rest of my trip!

Something seems fishy here…warm blooded fish?

Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus

Wegner, N.C., Snodgrass, O.E., Dewar, H., Hyde, J.R
Summarized by Sarah Sheffield

Lampris guttatus, a fish who is able to produce its own body heat! (Source: fishbase.org). This fish is found worldwide, though it’s especially common in Hawaii and west Africa.

What data were used?
Captured and freely-swimming opah fish

Methods
Researchers measured the body temperatures of captured and freely swimming fish at their natural depth. Temperatures were taken in multiple places along the fish, including the temperatures of a number of the muscles. These measurements were taken by heat monitoring sensors placed in the muscles of the fish.

Results
Researchers found that the core of the fish (pectoral muscles, heart, etc.) were much warmer than the surrounding environment. The cold, oxygenated blood of the fish is warmed by the conducting of heat from the warmer, deoxygenated blood leaving the respiratory system before the oxygenated blood reaches the respiratory system. This indicates that these fish, just like humans and all other mammals, are able to produce their own body heat (“warm blooded”) as opposed to creatures like reptiles, who rely on external sources, like the sun, to maintain their temperature (“cold blooded”).

Why is this study important?

The temperature of an opah fish as taken by the scientists of this study. Measurements were taken ~4-5 cm below the skin of the fish for 98 cm, the length of the fish’s body.

We’ve all learned from school that critters like reptiles and fish are cold blooded, whereas mammals (like us) are warm blooded. Simple, right? It turns out, it’s not nearly as simple as that! More and more, scientists have begun to discover that there are many animals that don’t fit into these neat categories, the opah fish being the most recent of these. This is important because in the fossil record, we don’t have the luxury of examining animals while they’re still alive, so we need to look for other clues! Dinosaurs and pterosaurs are excellent examples of this-we’ve always thought reptiles were cold blooded. But dinosaurs, like Velociraptor, had feathers! They had larger brains! Pterodactyls could fly by flapping their wings! All of these are examples of warm-blooded behavior. Fish like the opah show us how what we thought we knew might not always be the case!

The big picture
The picture that I want to stress here is that even the big things we thought we understood in science-like who’s warm and cold blooded-are subject to change with new data! Only within the last few decades have scientists begun to ditch the idea that animals fall neatly into categories of “warm” and “cold” blooded. It’s also important to note that discoveries such as these open our interpretations of extinct organisms-like dinosaurs, pterosaurs, and yes, even fish!- and how they were able to generate energy. Since we can’t bring a live pterodactyl (at least, not yet! Maybe we’ll learn more after watching Jurassic World: Forgotten Kingdom) in for testing, data such as these remind us that life isn’t as simple as just ‘warm’ and ‘cold’ blooded.

Citation
Wegner, N.C., Snodgrass, O.E., Dewar, H., Hyde, J.R., 2015, Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus: Science, v. 348, p. 786-789, DOI: 10.1126/science.aaa8902

Teaching effectively for all students

Sarah here –

I’m in my first year of teaching at the University of South Florida. I’ve had almost 700 students come through my classroom, just in my first two semesters! I wanted to write a little bit about what I’ve learned about making my lectures work for students of all different backgrounds. USF is a wonderful place to do this because our students come from every background imaginable! We have students from nearly every country on Earth, every native language, religion, socioeconomic and veteran status, etc. imaginable! It’s one of the things I love most about USF- I get to learn all about the world through my students. This unique community also presents me with the opportunity to make my lectures and my teaching style accessible to students who are English language learners (ELLs)-you may have referred to these students as ESL (English as a second language) in the past-educators have moved away from using that term because many students are actually learning English as a third and even fourth language! A large percentage of USF students are classified as ELLs-and they come from all over the world! Just in the past year, I’ve had the pleasure of working with students from Brazil, Venezuela, Nigeria, Germany, Finland, Russia, China, Japan, Oman, Saudi Arabia, Palestine, and more.
The introductory course I teach-History of Life-is very heavy in scientific jargon, no matter how you slice it (e.g., the names of dinosaurs, geologic time periods, etc.), so I’ve been working with my ELL students to help them feel more confident in the class. I’ve listed some of the methods I’ve found useful below!

Essay questions

All of my exams have short answer components, where they have to take scientific evidence and present conclusions. I write 2-3 questions per lecture topic and post them as a discussion board on Canvas (or Blackboard, or any sort of other online gradebook/digital classroom environment). I have seen dramatic improvements in the confidence levels of ELL students, as well as native English speaking students, when handling the essay portions of the exam. Allowing them to practice their communication skills in advance has allowed them to excel. I never tell the students which questions I am choosing for the exam, but this way, students can post their answers on the discussion boards, so that I can spend a few seconds working with them one-on-one. It might seem like a lot of work, but truthfully, it’s only about a ½ hour out of my week, usually.

The geologic time scale

To help students learn these very odd words more easily, I have located geologic time scales in as many languages as possible. Students who speak languages, especially, that aren’t rooted in the Roman alphabet have found that it is much easier to make connections with these terms. (The ICS has a bunch of those time scales listed here)

A vocabulary list

As a rule, my exams are not about vocabulary. Meaning, my multiple choice or essay questions are not asking you to define terms-students have to use the terms to explain phenomena we see in the geologic record. However, the amount of vocabulary in a science class is daunting for many, so one way that I can boost students’ confidence is to provide a list of vocabulary I expect them to know (e.g., Tyrannosaurus, Devonian, albedo) so that they know on the exam what words they will be expected to know.

An example of one of my slides with the term defined (this day, I had a  Star Wars themed lecture).

Posting unfamiliar terms on the PowerPoint slides

I generally don’t use too much text on my slides-but I do make sure to put the topic of the slide, any scientific words, and image descriptors on the slides (or at least in the notes). This helps students who may feel overwhelmed with just trying to figure out vocabulary words merely from me saying them out loud (English words really aren’t the easiest to spell, are they?)

Using familiar words

I’m still working on this one, for sure. I try to make sure that my lectures and my exams use common words. For instance, I have used words like ‘hypothetical’ and ‘plummet’ before on exams. ELL students who might be unfamiliar with some of these words can often feel overwhelmed. I do my best to a) make sure students know that they are welcome to ask me to define non-vocabulary words b) provide alternatives to these words on the test (for example-hypothetical (imaginary)) or c) avoid using words (e.g., use “drop sharply” instead of “plummet”) that might add to the stress of exam day.

Only assign videos that have great subtitles

I have my students watch a number of documentaries to learn more about certain materials. However, I have noticed that a number of videos posted on, for example, YouTube, might not have reliable captions, making it very difficult for ELL students to fully capture the science presented.

Use the microphone

My classes are big-my largest is just under 200 students. I am not a very loud person, usually, but if I need to, I can make myself heard for a 75-minute lecture. However, many students find it harder to understand words if they cannot hear them as loudly and as clearly. Using a microphone relieves the stress of many students. Even if you feel that you are loud enough, still consider using the microphone! (Bonus-this is also a huge help for hard of hearing students).

These techniques are meant to help my students feel more confident about their knowledge in my class. By making these small changes, I have found that my class is much more accessible to a larger percentage of the class and that students are giving me better and more detailed answers and they are able to make higher-level scientific deductions-which is what any science instructor wants, right? As an added bonus, many of these methods are also very helpful to students from any background who aren’t so confident in their writing skills, or who missed class due to illness or emergency, or to students with accommodations (e.g., ensuring that there are captions on videos and that your PowerPoint slides have image descriptions) also allows Deaf and hard of hearing students to have full access to your class, too! I hope that I can continue to make my classes more accessible-if you have any tips, please feel free to comment below!