Reconstructing the Eocene’s Climate System

Reconstructing Eocene Eastern Indian Ocean Dynamics Using Ocean-Drilling Stratigraphic Records

Ke Xu, David De Vleeschouwer, Maximilian Vahlenkamp, Renchao Yang, and Honghan Chen

Summarized by Olivia Cashimere, who is pursuing her Masters in Geology at Binghamton University. She is currently in her first year, and after graduation would like to work at a research museum. When she is not studying she enjoys hiking, traveling, and a variety of art mediums.

What data were used: This study focuses on two ocean drill hole archives, Ocean Drilling Program Sites 762C and U1514, located within the Eastern Indian Ocean. This study is concentrating on a 22 million year time span within the Eocene Epoch. This time period was leading up to a transition from a greenhouse to ice house climate conditions during the Cenozoic. During this time not much continental ice is seen around the globe, so not many ice related positive feedbacks are seen throughout the Eocene however, strong correlation is found between Milankovitch cycles and the climate changes. This study also uses previous studies on paleomagnetism and biostratigraphy to determine ages, and to check for ambiguity within the record.

Methods: This data collected from ODP Sites 762C and U1514 was applied to orbital scale dynamics using existing sedimentary sequences with biostratigraphy, radio-isotope dating, and magnetostratigraphy. Then stratigraphic interpretation from Site 762C is combined with an existing age depth model from Site U1514 to create a high resolution timescale for the Eocene. Downhole wireline logging with a natural gamma radiation spectrometer was also used to provide elemental data of potassium, thorium, and uranium. These help determine mineral composition, humid vs. dry environments, and astronomically forced climate signals. Using the log10 (Th/K) data a time series analysis was developed, omitting any gaps from poorly recovered core in the data. Previous studies done on Hole 762C provides data and analysis on the magnetostratigraphic record and calcareous nannofossil biostratigraphy. This data was combined to create a reconstruction of the Eocene timescale.

Results from the study showing the analyses in six panels.
Interpretation of ODP Site 762C 180-289.75 meters below sea floor in the core. The solid purple line at 249.41 mbsf, is a paleo magnetic anchor point at the Chron boundary. The blue sawtooth line (a) is the log10(Th/K) and the green line (b) is a 100 kyr filter, while the red is a 405 kyr filter. (c) Next is the FFT spectrogram of the log10(Th/K) depth series and (d) the power spectrum of the log10(Th/K) depth series. (e) The black sawtooth line is the tuned log10(Th/K) time series while (f) the green line is the 100kyr filter and red is the 405 kyr filter. (H) Next is the evolutionary FFT spectrogram of log10(Th/K) time series and (i) the power spectrum of the log10(Th/K) time series.

Results: The log10 (Th/K) analysis variability is found in cyclic patterns that roughly match with age depth, with an important note that there are four major gaps found in core recovery. Spectral analysis and depth-series provides sufficient data that sediment accumulation is steady, and power spectrum analysis identifies time series, prominent cycles, and peak frequencies exceeding 99% confidence level. Using the biostratigraphic markers previously found, the orbital tuning for Site 762C, correlated with a 405 kyr eccentricity cycle, and the paleomagnetic data was revamped to match boundaries, however, because of poor core recovery much of this data is still ambiguous and will require further studies. However with this record it reduced the number of gaps from six to four. This allowed for a supported hypothesis overall, and the combined research created an Eocene astronomical timescale that has correlated collected data across various other research methods.

Why is this study important? This study is focusing on key forcing factors that could have changed the climate dramatically during the Eocene. During this time period it is believed that there was very little continental ice across the globe, so any positive feedback from these ice sheets would be mostly nonexistent. However, we must have forcing factors that effect the environment. This study is theorizing on the possibility of astronomical forcing in deep-water circulation in the western North Atlantic. This study also identifies obliquity as the driver of Eocene climate conditions. This can be applied to current day climate systems to theorize about the current global climate warming and its effects of the planet. 

The big picture: The obliquity of Earth’s rational axis plays an important role in the deep water circulation and the movement of sediment supply. Low obliquity can be found to coincide with the cooling of ocean temperatures, and high obliquity with its warming. This idea can be used throughout may areas of study to increase our knowledge of how the Earth’s rotation changes our climate systems, and how sediments have been transported through ocean systems in the past. 

Citation: Xu, K., De Vleeschouwer, D., Vahlenkamp, M., Yang, R., & Chen, H. (2021). Reconstructing Eocene Eastern Indian Ocean Dynamics using ocean‐drilling stratigraphic records. Paleoceanography and Paleoclimatology36(2). https://doi.org/10.1029/2020pa004116 

 

Colin Boisvert, Paleontologist (in training)

Describe your hobbies and interests outside of science. I am an avid reader both in non fiction related to paleontology, evolutionary biology, a lot of different scientific subjects in general and fantasy, science fiction and some other fiction. A few of my favorite authors include Pierce Brown, Christopher Paolini, Edgar Rice Burroughs, and Frank Herbert. I am also a huge nerd when it comes to a lot of popular media franchises such as Star Wars, Indiana Jones, Jurassic Park, Lord of the Rings, Harry Potter, MCU, DCU and  Ghostbusters to name a few and quote movie lines all the time. I am a big costumer and have built my own Mandalorian armor among other costumes such as  the First Avenger Captain America  and Obi Wan Kenobi. I love to hike with friends, swim, and travel to new places (especially those with paleo stops).  I love spending time with my family and friends and am a big foodie.

Colin sitting next to a neck vertebra in a room full of bones.
Me in the middle of taking photos of a cervical (neck) vertebra from my specimen in the North collections at the BYU Museum of Paleontology as part of the photogrammetry process. This process is used to make 3d models of the neck bones for my specimen of Apatosaurus excelsus.

Discuss anything else about yourself that you’d like to share that doesn’t have to do with your career. I grew up in the Silicon Valley in Northern California which shaped my love for paleontology and my love of some of my hobbies. I spent a lot of time outside, especially as my Grandparents moved when I was younger to the Santa Cruz Mountains where I fell in love with the forests there. Much of my family lives in Northern California and I have remained close with all of them.  I love meeting new people, especially other scientists! 

What is your role? I am a Vertebrate Paleontology Graduate Student working towards my Masters in Geology focused on Vertebrate Paleontology at BYU. Currently that just makes me a Mr. Boisvert but working towards eventually becoming Dr. Boisvert! I am currently working with Sauropods and specifically the neck biomechanics of Apatosaurus excelsus to understand more about how this animal held its neck and what the species’s possible feeding envelope was.

Do you conduct outreach? I would love to get into more outreach with school age kids here in Utah. I was an education intern this past summer at the Mammoth site in Hot Springs, South Dakota and loved it! However nothing is set up at the moment, so the only science outreach I communicate on is with my fossil Friday posts! 

Colin holding up a cast of an Allosaurus skull.
The BYU Museum of Paleontology recently had professional shots done with photographers from campus using some of the specimens on display. This is a favorite shot of mine illustrating a pose similar to the classic Alas poor Yorik pose from Shakespeare with a cast of the skull of Big Al ( famous specimen of Allosaurus jimmadseni). While I do love studying sauropods, Allosauroids will always have a special place in my heart.

What is your favorite part about being a scientist, and how did you get interested in science? My favorite part of being a scientist is getting to work to uncover the past every day and sharing my discoveries with people.  I get some of the greatest joy when I get to give tours or share what I have learned about prehistory and learning that while doing research is an equally amazing feeling. Having conversations about current topics in the field of paleontology is an exciting prospect that I always look forward to at conferences or over zoom. I became interested in paleontology at a young age, took earth science, biology, and chemistry in high school. From high school, I attended UC Davis where I did a double major in biology and geology. I had a status year where I was a tutor and then worked as a Mammoth Site Intern in the summer of 2021 and since August of 2021 have been working on my Masters at  Brigham Young University.

Besides paleontology, I love learning more about geology, evolutionary biology, phylogenetics and biogeography in general. I also enjoy learning more  about the history of different sciences including paleontology, geology, and the theory of evolution. Besides my project I would love to tackle scientific questions relating to the Mid-Cretaceous Sauropod Hiatus where we don’t see Sauropods in North America and Europe for between 25-30 million years in the fossil record.  I would love to help close the gap between the transition of Dinosaur fauna in Western North America between 95-80 million years ago as well as what dinosaurs lived in Appalachia, the Eastern half of  North America. Finally it would be interesting to test comparisons between famous North American faunas like that at La Brea Tar Pits vs the Morrison Formation and what similarities in ecological roles there are between the two ecosystems.

How does your work contribute to the understanding of evolution and paleontology? My work contributes to paleontology through how this research with Apatosaurus can help us more with understanding this sauropod’s neck posture and range of motion. By understanding how this animal moved and what it fed on, we can better understand the Morrison environment in one small aspect. At the time of my specimen, we have 5-7 large coeval sauropod species and by understanding the diet of this species we can begin to piece together the puzzle of how all these animals were able to coexist. The specimen I am studying is unique as it does not suffer from several of the problems plaguing sauropod neck studies such as bone distortion and incompleteness of specimens.

Colin standing outside of the BYU Museum on a snowy day, with snow covering the pines and cars behind him.
Me standing right outside the BYU Museum of Paleontology where I have conducted most of my research so far ! It has a world-class paleontology collection and is a fantastic place to visit.

How does your outreach contribute to or benefit society? Fossil Friday posts such as mine  are important for helping to engage those connected to scientists through social media, spreading information about unique species, specimens and collections that  are out there and providing recognition of the work that is done in our field and localities people should visit. A smile put on someone’s face learning about the past today, can inspire a budding scientist for tomorrow.

What advice do you have for up and coming scientists? Science is rough and not always a 9-5 job. It may require early mornings/late nights but the work is worth it and there is such an amazing feeling you get when you can present research at a conference and talk with colleagues about what you are studying. I wish I had known that jobs are difficult to come by as are graduate student positions so working really hard helps with being more competitive when applying to positions. Reading scientific papers is important for developing a good understanding and field vocabulary.

Have you received a piece of advice from your friends, mentors, or advisors that has helped you navigate your career? Looking for a variety of programs can help with applying to graduate school, publishing is very important and problem solving is key for scientists. I also learned two key tips for investigating possible graduate programs. 1, it is very important that you and a possible adviser can get along and will you get along if you attended there. 2, are they studying similar organisms/using techniques you wish to learn about so they can help you more when you have trouble with projects.  Making an attempt to establish contact with a potential advisor before applying is a great way to build a relationship with them and can help with your application. It can be as simple as having a zoom meeting to discuss their research lab and interests.

Learn more about Colin by following him on Twitter, Instagram, and LinkedIn

The first sea-surface temperature model based on Porites astreoides coral skeletons

The potential of the coral species Porites astreoides as a paleoclimate archive for the Tropical South Atlantic Ocean

N.S. Pereira, A. N. Sial, R. Frei, C. V. Ullmann, C. Korte, R. K. P. Kikuchi, V. P. Ferreira, K. H. Kilbourne

Summarized by Harry Janoff, who is currently a senior at Binghamton University and is majoring in Geology. After graduating from Binghamton University, Harry plans to find entry-level work in order to receive more field experience. He is unsure if he will return to grad school right now but he has definitely considered it and definitely does not want to go until he has more experience in the field. When he is not studying Geology, Harry loves to play chess and the violin.

What data were used: In their research, Pereira and their team use aragonitic coral skeletons to create records of strontium to calcium ratios and records of d18O and d13C in order to determine ancient environmental conditions of the ocean. They also used the coral’s skeletons to create the first ever d18O calibrations based on sea surface temperatures for the Porites astreoides coral species.

Methods: Pereira and their team collected Porites astreoides samples from the Rocas Atoll, located about 270 kilometers from the northeast coast of Brazil, because it is the only atoll present in Western region of the South Atlantic ocean. They collected series of sea surface temperature data for the region through the use of the NOAA pathfinder AVHRR between October 2012 and October 2013 and collected samples of P. astreoides coral from the atoll’s Cemiterio tide pool during July of 2013. The Porites samples were then cut into 5 mm thick samples and from those, carbonate samples were collected at .5 mm intervals.

The geochemical analysis of these coral samples was performed at the University of Copenhagen and involved the use of a Micromass IsoPrime mass spectrometer to measure the d18O and d13C isotopes. Coral Sr/Ca ratios were measured using a Perkin Elmer Optima 7000 DV ICP-OES and the samples were measured at a calcium concentration of ~10 mg/g.

Results: The researchers found that the two isotopes had abundance rates of 0.09‰ for d13C and 0.10‰ for d18O. They also discovered that the Sr/Ca ratios and isotope cycles displayed seasonality between 2001 and 2013. The Sr/Ca values for the coral varied between 8.86 to 9.15 mmol/mol and the mean value for the samples was 8.98 mmol/mol. d13C values for this research ranged from -1.38% to 1.05‰  with a mean value of 0.07‰ and the annual cycle for d13C contained the most positive d13C values in September and the most negative values in April or May. d18O values range from -4.26 to -3.69% and their mean value was -3.96‰. Unlike the d13C values, the d18O values were found to be  highly consistent overall, but there was a small increase in more-positive values during the years of 2006 and 2007.

Graphs of data that indicate sea surface temperatures and other surface ocean conditions as obtained from the Porites corals.
The data collected from 2001 to 2013 using the Porites coral was plotted into graphs and includes data on d13C concentrations, d18O concentrations, Sr/Ca values, sea surface temperatures, and rainfall in millimeters. The d18O, Sr/Ca and SST data are all cyclical and contain peaks towards the beginning of years and low points during the middle of years. d13C is the only outlier because its peaks are in the middle of years while its low points are closer to the beginning of years. The highest amount of rainfall was recorded around the middle of 2007 and this peak correlates to one of the largest sea surface temperature dips and a dip in Sr/Ca and d18O.

Why is this study important? This study is incredibly important because knowing the cycles in d13C values and consistency of the d18O values allows us to begin piecing together the conditions where these coral skeletons formed. Pereira and their team’s research was also the first to relate these Porites astreoides values to sea surface temperatures, which will allow us to learn even more about, and maybe fully understand, the climate when these corals were formed. This study also creates links between d13C concentrations and sea surface temperature through the coral skeletons. By understanding the conditions under which these coral formed, we are able to understand climate cycles that have occurred within the Southern Atlantic ocean. Using that information, we may be able to interpret what the climate of this region was like in the past and what it may become in the future. 

Citation: Pereira, N. S., Sial, A. N., Frei, R., Ullmann, C. V., Korte, C., Kikuchi, R. K. P., … & Kilbourne, K. H. (2017). The potential of the coral species Porites astreoides as a paleoclimate archive for the Tropical South Atlantic Ocean. Journal of South American Earth Sciences77, 276-285.

 

Interpretation of the Effects of Climate Change in the Middle East

Climate Change, Dust Storms, Vulnerable Populations, and Health in the Middle East: A Review

Muge Akpinar-Elci, Brenda Berumen-Flucker, Hasan Bayram, Abdullah Al-Taiar

Summarized by Ethan Penner, who is a geology master’s student at Binghamton University. He graduated in May 2021 with a BS in geology and is currently working on a thesis concentrated on the tectonic geomorphology of the McGregor fault, located in east-central New York. After graduate school, he plans to apply to the USGS or look for environmental consulting positions and hopes to teach in the future. Some of his hobbies outside of geology include gardening, exercising, hiking and sight-seeing.

What data were used: The data that was used in this study includes articles detailing how climate change and climate variability impact the frequency and severity of dust storms, as opposed to the more common effects of increased sea level and global temperatures, worsening air pollution, and increasing extreme weather rates, on human health. The covered articles themselves deal with data ranging from dust and air samples to illness statistics.

Methods: The authors use a systematic review to determine how dust storms affect the Middle East and its populations and searched for literature on the topic through Google Scholar as well as MEDLINE/PubMed. Articles that were utilized were  published between 2008 and 2019, written in English, and had to be full texts from scientific journals. Their search involved the keywords of “Middle East,” as well as “dust storm” and “health.” They also included individual country names following their initial review of articles (ex. “Iran, dust storm, health”). Countries were identified using the U.S. CIA’s World Factbook. Defining the “Middle East region” is difficult since the official number of countries is not set and not all resources offer the same definition of the territories. Because of this detail, Egypt was included as a part of the Middle Eastern region by the authors. The reviews studied by the authors only discussed health conditions, health outcomes, or diseases that currently affect human populations, especially those that have a strong correlation with local dust storms in the predetermined Middle Eastern region. Not all articles involving dust were included, meaning that articles discussing volcanic activity or human-induced dust production were excluded since these do not have to do with the scope of the authors’ analysis. The articles that did discuss dust exposure or dust levels but did not consider the effects on human health were also excluded. The health of animal populations was not considered when reviewing articles. The main extraction process for the utilized articles involved a review of the title and abstract, and then a review of the full text to check eligibility.

Flowchart detailing the process of selecting, then screening, and finally including texts on dust storms for the analysis, where arrows lead towards the end goal of analysis unless a text is excluded for inadequate content and the number of articles under scrutiny becomes smaller
Figure 1 shows the authors’ method of interpreting whether articles on climate change are related to dust storms and health impacts, and the number of articles goes from 534 to 31 based on full-text availability, and then from 31 to 16 based on quality.

Results: In total, 534 articles were checked for eligibility, but only 31 matched the necessary criteria. Of these 31 articles, 15 were excluded because of a lack of clarity concerning the impacts of dust on human health and the use of animal subjects. Therefore, 16 of the articles were used in the study, most (10) of which focused on Iran. Two of the studies focused on Kuwait, one focused on Kuwait and Iraq, one focused on Turkey, and the final study focused on Israel. The subjects of the articles ranged from threats to human health resulting from dust composition to measurable health impacts attributable to dust storm events. Leski et. al (2011) focuses on airborne particles within collected dust samples from Kuwait and Iraq. Nourmoradi et al. (2015) deals with similar data from Iran, and both studies detected potentially hazardous airborne bacteria and fungi in the air samples. Alavi et al. (2014) details the relationship between dust and pulmonary tuberculosis and found that dust had the potential to impact TB relapse and treatment outcomes. Al-Hemoud et al. (2018) found that dust impacted respiratory diseases in humans, as well as morbidity. These are just a few of the articles that were analyzed in depth to understand a large range of data and impacts, and the overall conclusion from these texts is that dust particulates, often carrying harmful bacteria and fungi, in a region of increasing climate change leads to more severe health effects as more populations are exposed, leading to more people suffering from deadly diseases, more hospitalizations, and possibly even increased mortality.

Why is this study important? This study is vital to the conversation of climate change because it highlights the issue of dust storms, which many likely do not consider as a severe impact when compared to rising sea levels and temperatures. The hidden threats within the air and dust strewn around arid regions affected severely by climate change can cripple populations and drastically impact ways of life in the same ways as conventional ideas of climate change effects.

Overall, the authors discuss how more research should be conducted to understand the relationship between climate change, air pollution, dust storms, and health conditions. Comprehending the scope of the impacts can lead to faster and more efficient solutions to health crises across the Middle East, and further analysis of dust storms/air pollution can help scientists mitigate climate to the best of their abilities.

Citation: Akpinar-Elci, M., Berumen-Flucker, B., Bayram, H., & Al-Taiar, A. (2021). Climate Change, Dust Storms, Vulnerable Populations, and Health in the Middle East: A Review. Journal of Environmental Health, 84(3), 8-15.

 

Fossilized Mollusks used to determine Cenozoic climate and elevation of the Himalayan-Tibetan Plateau

Clumped isotope thermometry of modern and fossil snail shells from the Himalayan-Tibetan Plateau: Implications for paleoclimate and Paleo-elevation reconstruction

Yang Wang, Benjamin Passey, Rupsa Roy, Tao Deng, Shijun Jiang, Chance Hannold, Xiaoming Wang, Eric Lochner, and Aradhna Tripati

Summarized by Brynn Crocker, pursuing a master’s in teaching at Binghamton University with a bachelors in Geology. 

What data were used: Both fossilized and modern aragonite mollusk shells were collected from seven different lakes within the Tibetan Plateau. The fossils collected from these sites were dated to be of Cenozoic age. Clumps of carbon 13 and oxygen 18 (isotopes of carbon and oxygen) were measured to determine paleo-temperatures. The formation of the Himalayan Mountains is thought to have had a large impact on the regional climate during the time. Mollusk fossils are great archives for determining paleoclimate.

Methods: This study used X-ray diffraction to determine the values of C13 and 18O bonds (clumps) within the shells. These clumps help determine paleo temperatures and elevations. Modern shells both alive and dead were collected from the lakes in the Tibetan Plateau. The fossil mollusks were collected from fine grained sandstone, indicating that they were not transported there but lived in the freshwater lakes. These shells were then analyzed to find their clump values, which were then compared to modern temperatures. Intact Cenozoic fossil shells were then collected and analyzed to find their clump values. Intact shells were used to avoid using shells that have gone through any diagenetic alteration (changes to the fossils through heat,  pressure, and chemistry). Shells that contain calcite indicate diagenesis. Trace amounts of calcite yield temperatures of an average ~10º C lower than those with no calcite from the same strata. Shells were cleaned using HCl (hydrochloric acid) solution and then rinsed with distilled water. Modern shells were soaked in 30% H2O2 (hydrogen peroxide) to remove any organic matter. The isotope clump data was reduced using both the Henkes calibration and the Eagle calibration.

Black and white map showing the location of the study areas.
This figure shows the region of study and the basins within the area.

 

Results: After analyzing the 13C-18O clumps it was determined that southwest Tibet was warmer 4-5 Ma than today and paleo-elevation was similar to today. Using the Henkes calibration of temperatures calculated from the clump values, the temperature of the Himalayan-Tibetan Plateau ranges from 1ºC to 17ºC, with a mean of 10ºC. Using Eagles calibration, the temperature values range from 8ºC to 21ºC, averaging 16ºC. The Henkes calibration is better used for freshwater shells. There were no former long term temperature records for the lakes within the Tibetan plateau. The difference in the modern shell clump values and the fossil clump values can be explained by a change in global climate. The temperature difference between fossil shells and modern shells, after adjusting for temperature change due to sampling elevation difference, is similar to the change in the global mean temperature since the Pliocene warm period. This result tells us that the elevation during the Cenozoic was similar to today. These findings have important implications for paleoclimate and paleo-elevation reconstructions using clumped isotope data from aragonite fossil shells.

Why is this study important? This study provides additional paleo-temperature data that can be used for future paleoclimate research. The affect that tectonic events have on our climate can be significant and the significance of the Himalayan Orogeny on the climate is still disputed. This study can provide more insight on the temperatures of the surrounding areas during that time. Understanding the paleoclimate of our planet can help us better understand how it will react to things in the future.

Chart with water oxygen 18 values on the y-axis and study sites on the x-axis.
This figure represents the calculated d18O values using the Henkes calibration vs the Eagles calibration vs the actual d18O values of the water from the lake sites. The error bars indicate 1 standard deviation.

Citation: Wang, Y., Passey, B., Roy, R., Deng, T., Jiang, S., Hannold, C., … & Tripati, A. (2021). Clumped isotope thermometry of modern and fossil snail shells from the Himalayan-Tibetan Plateau: Implications for paleoclimate and paleoelevation reconstructions. GSA Bulletin133(7-8), 1370-1380.

Anoxic Conditions in the Northern Gulf of Mexico Predicted to Increase as Climate Change Continues

Climate change projected to exacerbate impacts of coastal eutrophication in the northern Gulf of Mexico

Arnaud Laurent, Katja Fennel, Dong S. Ko, John Lehrter

Summarized by Kristina Welsh, who is currently a junior at Binghamton University pursuing a B.S. in Environmental Science with a concentration in Natural Resources and a minor in GIS. Kristina hopes to pursue a job involving field work and travel opportunities. In her free time, Kristina enjoys camping, biking, and hanging out with her dog, Bailey.

What data were used: This study uses data from past published articles to compare present and future conditions intheGulf of Mexico. A present condition model was created using data from the Intra-Americas SeaNowcast-Forecast System. The future model was constructed using data from MPI-ESMRPC 8.5.

Methods: This study uses two 6-year physical-biogeochemical model simulations from the Regional Ocean Modeling System to represent present and future conditions in the northern Gulf of Mexico. Initial and open boundary conditions, river discharge, atmospheric temperature and pCO2 (atmospheric carbon dioxide) were variable in both models; all other factors were kept constant. The present simulation, which covers the period of 2005-2010, uses data from the Intra-Americas Sea Nowcast-Forecast System. The future simulation represents a 6-year period at the end of the century. The future model parameters were set with a 10% increased discharge from the Mississippi River, an air temperature increase of 3 ºC, and an atmospheric pCO2 increase to 935.85 µatm. Although conditions of river nutrient load were kept the same, the increased river discharge in the future model will dilute nutrient concentration results.

Four models (present on left, future on right) that show modeling results.
This figure illustrates the pH decrease in bottom waters that is predicted to occur in the future simulation. The bottom row shows how oxygen concentrations are expected to decrease.

Results: The future models predict a summer surface and bottom water temperature increase by 2.69ºCand 2.23ºC, respectively. The salinity of surface waters decreases by 0.48 due to an increase in freshwater river discharge in the model. As salinity in bottom waters is controlled by the saltier offshore water, only a decrease of 0.02 was observed. The reduced density of the warmer and fresher water lead to an increased stratification in summers by +12.35 J m^-3. These warmer waters cause lower oxygen saturation levels and thus lower oxygen concentrations, with summer surface oxygen concentrations 3.4% lower than the present average. The decrease in surface water oxygen saturation leads to a 9.4% decrease in oxygen concentrations in bottom waters. 60-74% of the decrease in oxygen concentration is a result of saturation-dependent effects, while the other 26-40% is a result of changes in biological rates and stratification. Lower oxygen concentrations in the Gulf of Mexico leads to an increase in extent and duration of future hypoxia conditions. Hypoxic areas increase by 26% and volume increases by 39%, resulting in more frequent anoxic surface and bottom waters. The future model increased surface pCO2 and alkalinity, causing a decrease in bottom water pH range of 0.37-7.58, with large spatial and temporal variability. Hypoxic waters in the Gulf predict an average pH 7.39. Present and future conditions vary year to year due to different along shore wind directions, upwelling, and river discharge, but overall follow the same trend.

Why is this study important? This study implies how human-induced climate change will exacerbate hypoxic conditions and eutrophication-driven acidification in the northern Gulf of Mexico by the end of the century. Future hypoxic conditions will create growth and reproductive impairment to many sensitive species living in the Gulf. Changes in atmospheric CO2 can influence ocean pH and air temperatures, producing other negative effects on water chemistry, and plant, and animal life, creating a positive feedback system that will exacerbate these changes. 

The big picture: This study adds to our understanding of the risks of climate change. As this model interprets the impacts of climate change on nature and human sustainability, we can visibly see how the Earth’s oceans will change globally as well as locally. This article gives us evidence as to why we need to take action now so these changes do not occur.

Citation: Laurent, A., Fennel, K., Ko, D. S., & Lehrter, J. (2018). Climate change projected to exacerbate impacts of coastal eutrophication in the northern Gulf of Mexico. Journal of Geophysical Research: Oceans, 123(5), 3408–3426. https://doi.org/10.1002/2017jc013583

Colonization and Sea Level Rise Effects on Carbon Storage in Freshwater Wetlands of Southeastern United States

The Impact of Late Holocene Land Use Change, Climate Variability, and Sea
Level Rise on Carbon Storage in Tidal Freshwater Wetlands on the Southeastern United States Coastal Plain

Miriam C. Jones, Christopher E. Bernhardt, Ken W. Krauss, Gregory B. Noe

Summarized by James Myers who is a graduate student at Binghamton University earning his masters in teaching for earth science. As an undergraduate he majored in environmental
chemistry. Not long after he decided he wanted to become an educator and work towards
creating the next generation of environmental scientists. In his downtime he enjoys playing
guitar, camping, and watching hockey.

What data were used: Sediment cores were collected along the Waccamaw River in South Carolina and the Savannah River in Georgia. The sites were chosen because they have similar landscapes, ranging from freshwater, to moderate salinity, and oligohaline marsh. Four piston core samples were taken from the Waccamaw River, one that was found in freshwater, one in moderately salt-impacted water, and two from the Sampit River, one from a heavily salt-impacted area and one from an oligohaline marsh. Four other cores were collected along the Savannah River using a peat corer. These core sites were also from freshwater, moderately salinated, highly salinated, and an oligohaline marsh.

Three maps of the Savannah river, Waccamaw River, and an inset map showing the location of both rivers along the southeastern United States.
Maps designating the locations of the sites sampled. The sites are roughly 150 km away from each other, along the southeastern coastline of the United States. The Savannah River sites are found further upstream compared to the Waccamaw River sites. The cores at both locations were assigned numbers from one to four. The lower numbers are further upstream and are lower in salinity.

Methods: The cores were dated using radiocarbon analysis on macrofossils and bulk sediment which helped determine which samples were from the colonial era. Time scales were reported with calibrated years before present from 1950. Core compression was apparent within the samples, and bulk density (weight of sediment in a given volume) and accretion rates (how fast sediment accumulates) were adjusted to account for this. Carbon content was calculated using the loss on ignition method. Carbon accumulation rates were calculated by multiplying the percent carbon by the bulk density and accretion rate determined from an age-depth model. Pollen analyses were run to understand which plant species lived at these sites over time, as this method revealed what the environment must have been like if certain plants and trees were able to survive.

Results: The core samples from the Waccamaw river dated between the last 1,100-4,200 years. The oldest sample was the heavily salt-impacted site, which began as a back swamp environment, where fine silts and clays settle after flooding which create a marsh-like landscape. This was determined from the presence of Nyssa, Taxodium, and Poaceae pollen. The accumulation rates are low, but still higher than the freshwater sites. Upper freshwater and oligohaline sites were also found to have been back swamps due to the presence of Alnus in the freshwater core, and Liriodendron tulipifera seeds found at the oligohaline marsh site, as well as Nyssa, Taxodium and Alnus pollen found at both sites. The accretion and accumulation rates are similar to the heavily salt-impacted site. Freshwater environments are characterized by low accretion and carbon accumulation. Higher accretion and carbon accumulation rates are found around 1700-1400 calibrated years before present, and can be seen in the cores with a decrease in hardwoods and increasing Nyssa, Taxodium, and Liriodendron evidence. The largest observed changes happened around 400 years ago, the same time of colonization and the increase in agriculture within the regions. The changes are marked in the cores by large increases in accretion, organic matter, and carbon accumulation. Another indicator of this is the increase of Poaceae, while evidence of Nyssa, hardwoods, and Taxodium diminish. Poaceae pollen and the presence of Scirpus and Carex seeds suggests a change to oligohaline marsh in relation to the increase of land use in the area. Reforestation efforts over the last 100 years show a decrease in accretion and carbon accumulation in all sites. The Savannah River cores were found to be roughly five to six thousand years old. The results from the cores along the Savannah River were found to be very similar to those from the Waccamaw River.
The study revealed that the same zones were also back swamps and that the freshwater core showed low accretion and carbon accumulation. The presence of Alnus designated this back swamp environment. Around 2,000 calibrated years before present, the sites show various changes in biota, but very little change in accretion and carbon accumulation rates. The largest change in the Savannah samples are found around 400 years ago, as was seen in the Waccamaw cores. All sites showed a decline in Nyssa, and an
increase in Poaceae, and what the researchers call weedier taxa, such as Scirpus, Sagittaria, and Polyganum. Both the Savannah River and the Waccamaw River both show stark increases in carbon accumulation and accretion rates right at the start of when colonization and agriculture increased in these regions dramatically, as well as when sea-level rise began to increase during the Holocene. The lowest accretion rates were found further inland, which is tied to an expansion of the marsh. Reforestation efforts coincided with lowered accretion rates, which increased the vulnerability with a rise in sea level. The tidal freshwater forested wetlands are vulnerable to the smallest of salinity changes.
Why this study is important? Wetlands like the ones studied in this research, are important for coastal communities because they help mitigate flooding and support many organisms, as well as fisheries, which provide millions of dollars in commercial and environmental goods and services. Wetlands are also important carbon sinks and help control the amount of CO2 in the atmosphere. Sea level rise today will affect these ecosystems and the people living near them. The results of this research are important for understanding the future long-term resilience of these ecosystems and what measures will be best suited to support these environments.
The big picture: The paper looked at evidence within sediment cores to understand the changes in carbon accumulation and accretion within two southeastern United States rivers. Core evidence indicated that there were increases in accretion and carbon accumulation rates with the emergence of colonization and agriculture in the area. Reforestation efforts in the last 100 years showed a decrease in accretion. The findings were then compared to sea level rise data to show that these environments become more vulnerable with increased sea level rises over the last 200-100 years. This research will be helpful in understanding the effects sea level rise in the future will have on this environment and the surrounding communities.
Citation: Jones, M. C., Bernhardt, C. E., Krauss, K. W., & Noe, G. B. (2017). The impact of late Holocene land use change, climate variability, and sea level rise on carbon storage in tidal freshwater wetlands on the southeastern United States coastal plain. Journal of Geophysical Research: Biogeosciences, 122(12), 3126–3141. https://doi.org/10.1002/2017jg004015

How global warming is changing the ecosystem in the Alps and Apennine Mountains

Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines

Rogora M., Frate L., Carranza M.L., Freppaz M., Stanisci A., Bertani I., Bottarin R., Brambilla A., Canullo R., Carbognani M., Cerrato C., Chelli S., Cremonese E., Cutini M., DiMusciano M., Erschbamer B., Gogone D., Iocchi M., Isabellon M., Magnani A., Mazzola L., Morra di Cella U., Pauli H., Petey M., Petriccione B., Porro F., Psenner R., Rossetti G., Scotti A., Sommaruga R., Tappeiner U., Theurillat J.-P., Tomaselli M., Viglietti D., Viterbi R., Vittoz P., Winkler M., and Matteucci G.

Summarized by Agnes Wasielewski, who is an MAT Earth Science Graduate student at Binghamton University. She loves Geology so much that she decided to share her passion with middle and high school students by becoming a teacher. When she’s not studying Geology or the psychology of teenagers; she spends a lot of time with her husband, three children, and three dogs. When free time becomes available, she loves to read, hike, drink tea, and take naps with her dogs.

What data were used? Researchers collected data from twenty research sites across the Alps (Italy, Switzerland, and Austria) and Apennines Mountains (Italy). All sites were located between 1300 and 3212 meters above sea level. Fourteen sites are in forests, grasslands, alpine tundra, and snow-covered areas. Six sites are in lakes and rivers. All sites considered for the paper experienced an increase in air temperature over the past two decades (1991-2015) compared to a base period of 1961-1990. A combination of data analysis on already existing datasets, projects, and new collection of data to determine results.

Methods: Temperatures taken in June were used to determine snow melting rates, the timing of the beginning of the growing season, and timing of ice-break in lakes and rivers. To analyze regional snow cover duration, data loggers combined with thermistors (special resistors used  for temperature measurements) were placed at a soil depth of 10 cm and measured hourly. If the temperatures measured remained within a certain range, the day was considered a “snow cover day”. On days where the daily mean soil temperature dropped below and rose above 0 degrees Celsius, they were labeled as a freeze/thaw cycle. The snow melting date is identified by counting the days since October 1st to the start of the freeze/thaw cycle or melting period. Soil samples were collected in September at the end of the growing season and tests are run to determine water content, carbon content, and nitrate concentrations. 

Changes in vegetation cover were calculated by estimating the percentage of each plant species in permanent grids over time. These estimates are used as a proxy for above-ground biomass. Biomass is positive when vegetation cover increases and negative when cover decreases. 

Surface water samples for chemical analysis were obtained from lakes in late summer/early autumn. May to October is considered open water season, and water temperatures combined with chlorophyll-a concentrations and zooplankton abundance are recorded. Weather stations were used to collect average air temperatures. Biologic samples were analyzed from rivers at varying distances downriver of melting glaciers to correlate community composition and diversity.

Location of research sites where data was collected throughout the Alps and Apennine mountains in central and northern Italy, southern Switzerland, eastern and central Austria.
Location of research sites used for analysis within Italy, Switzerland, and Austria. Degree of temperature change from the baseline reflecting global warming.

Results: At lower altitudes (~1500 meters above sea level) and latitudes (Lat. 41 degrees N), there are shorter snow cover duration (less than 100 days/year) and snow starts to melt earlier in the year. At higher altitudes (~2800 meters above sea level) and latitudes (Lat. 46 degrees N), there are longer snow cover duration periods (~250 days) and snow starts to melt later in the year. Less snow-covered days allow for increased soil temperatures and more areas for plants to grow and thrive. When more plants can grow and thrive, there are more resources available to local wildlife such as the Alpine ibex (mountain goat) and helps support their population growth. Overall, increased air temperatures and soil temperatures showed a general tendency towards increased vegetation cover for treeline, subalpine, and alpine belts but not in the snow (nival) belts. Over the last fifteen years, it is noted that plant species have been migrating from lower elevations to higher elevations in a process called thermophilization.

An increase in nitrogen deposition has positive effects on tree growth and promotes carbon sequestration (the process of capturing and storing atmospheric carbon dioxide). However, reduction in rainfall can override the positive effects. In the forests tested, a significant increase in the growing season length and a general increase in the annual net carbon sequestration was detected.

During warm and dry years, alpine streams transport concentrated solutes into the lakes and in the runoff water. Over the past decade, there has been a common trend in decreasing nitrate concentrations. Nitrogen uptake in the lake catchments has increased due to the increase in primary productivity (algae and vegetation growth). There has an overall negative trend in NO3 concentration level in rivers and lakes due to decreasing Nitrogen deposition. 

Changes in water mineral and chemical concentrations also affect the diversity and population of algae and plankton that live and thrive in mountain lakes and streams.

Why is this study important? Climate warming effects, changes in rainfall seasonality, and water availability have proven to be important for ecosystem productivity. Snow cover duration affects soil carbon and nitrogen cycling and Alpine ibex population dynamics. Warming climate change has shown to lead to an increase in vegetation cover in grasslands and carbon uptake in forests which helps remove CO2 from the atmosphere. Climate drives changes in water chemistry, lake thermal dynamics and plankton phenology can inform us of the health of the water ecosystems. High-elevation ecosystems may also be affected by extreme climatic events such as heat waves, droughts, heavy rainfall, and floods. Both long-term and short-term (extreme) events can affect mountain ecosystems. Mountain ecosystems, if properly studied and monitored, can serve as early indicators of global changes.

The big picture: Global warming affects high mountain ecosystems by increases in temperature, early snowmelt, and a prolonged growing season. With ecosystem productivity, more plant growth helps reduce global climate change by reducing the amount of carbon dioxide in the atmosphere. In mountain ecosystems, carbon sequestration depends on both water availability (precipitation) and air temperature. The understanding of hydro-ecological relationships is essential for the development of effective conservation strategies for alpine rivers. Long-term observations on benthic communities help with the assessment of the potential impacts of global change on stream ecosystems. There is a great need for strong partnerships in mountain ecosystem observation and research for multidisciplinary approaches, encompassing the distinction between different types of ecosystems. There is great potential for further scientific advances that rely on international collaboration and integration.

Citation: Rogora, M., Frate, L., Carranza, M. L., Freppaz, M., Stanisci, A., Bertani, I., Bottarin, R., Brambilla, A., Canullo, R., Carbognani, M., Cerrato, C., Chelli, S., Cremonese, E., Cutini, M., Di Musciano, M., Erschbamer, B., Godone, D., Iocchi, M., Isabellon, M., … Matteucci, G. (2018). Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines. The Science of the Total Environment624, 1429–1442. https://doi.org/10.1016/j.scitotenv.2017.12.155

Society of Vertebrate Paleontology 2021 Annual Meeting & their Paleobiology Database Workshop

Ibrahim here – 

The Society of Vertebrate Paleontology (SVP) is an organization with a goal of advancing science in the field of vertebrate paleontology worldwide. It was founded in the United States in 1940 and consists of approximately 2,300 members internationally. Every year SVP arranges an annual meeting with vertebrate paleontologists, writers, students, artists, and fossil preparators to share the latest research techniques, opportunities, workshops and also includes a prize giving ceremony. 

In 2021 I was lucky enough and won the Tilly Edinger travel grant of the Time Scavengers to attend The 81th annual meeting of Society of vertebrate paleontology (SVP). In 2020 it was my dream to attend the SVP annual meeting and the next year my wish was fulfilled, for this I especially thank the Time Scavengers team for providing me this opportunity. 

Due to Covid-19 the SVP annual meet has been held on an online platform since 2020 otherwise it would have occurred physically. Consequently I attended the 2021 online meet and it was quite easy and comfortable to attend . The event was held from 1st to 5th November and the virtual platform website became available from 25th October. The virtual platform had a simplified page by which one can easily click and view and attend the meeting they want. The talks , Romer prize and posters were recorded and uploaded on that site. Only networking sessions were done live. From the recorded talks I listened to the talk of Albert Chen et al. about phylogenetics insights from the pectoral girdle and forelimb skeleton of crown birds.

The coffee break session was interesting. The Remo app worked like a virtual hall room where anyone can walk around and have a sit and can talk to each other. 

On November 1st I attended the Paleobiology Database Workshop on Zoom, it was guided by professional group leaders (Mark D. Uhen, Evan Vlachos, Matthew Carrano, Pat Holroyd). It was my first time to visualize data from a systematic database. I enjoyed it very much as they were very helpful to show how to use the data from the Paleobiology Database (PBDB). PBDB is an online resource that includes data on fossil occurrences all over the globe. It is a community resource that is added to daily by scientists from around the world. The most iconic of the PBDB website was the navigator, where fossil discoveries are represented by dots in map view. If someone wants to study the fossil record of a taxa over chronological order it is also possible to view and collect data. It can show the diversity plotted on the map overtime. 

More data can be accessible if someone is an approved user. Everyone in the workshop was an approved user. The benefit of an approved user is that one can add data on the website. “Taxonomic name search form” can help to find out necessary data about a taxa and from where you can download the whole database about the taxa in Microsoft Excel file. Another helpful feature of the PBBD is you can find images from a ePanda API system of your required data to retrieve images from the iDigBio system. 

As a student of Geology with a great attraction to vertebrate fauna (especially dinosaurs), I enjoyed the Society of Vertebrate Paleontology’s annual meeting and would love to join an in person meeting in future if I get an opportunity.

Life Decisions

Anieke here–

It took a while, but I finally no longer feel like an imposter. My postdoc is going well. I’m confident, I know what I’m doing and I’m loving it. But the project is coming to an end and I have to think about the next steps. I’ve been in my current institute for nearly nine years, a mind-bogglingly long time in Early Career Researcher world, so a new job likely means a new institution. Quite possibly in another country, given the tight job market. Career-wise, I really like the idea of moving around the world for a few more years, work in different labs and do cool research with cool people.

Life-wise, I want to settle down, buy a house, and figure out if I want kids.

I’ll be 33 this year. After the age of 35 a woman’s chances to get pregnant decrease rapidly. These next few years, that career-wise are best spent hopping across continents, are also my last chance to have a family.  

That is, if I want kids at all. Which right now I really don’t know. I’ve always liked kids but never thought of myself as a mum. The time constraints are making this topic an increasing source of stress but I’m no closer to an answer. So what do I do with my job? Rule out major career options in favour of life question that I’ve not figured out yet? Or just go ahead with the postdoc route, likely involving some long-distance relationships with my partner and hope that life will sort itself out eventually? If I went with option 2 and changed my mind, I could always quit the post early to move back to my partner and try and start a family. But it won’t look great on my cv to walk away from a fellowship half-way through. In the hyper-competitive academic world, the tiniest drawbacks can cost you grants and job interviews.

Alternatively, my partner and I could both move. He’s super kind and supportive and would be up for it if I asked. But it would mean dragging him away from his job and life here for a temporary stay abroad. Plus, moving country is hard. It’s enriching, exhilarating and fantastic, but also terrifying, draining and lonely. If that’s how I felt moving for a job I loved, moving country for no reason other than that your partner is going will be even harder. What it would be like while at the same time trying to start a family, I don’t even want to know.

Early-career researchers hoping to balance work and life have to jump through nearly impossible hoops. I’m fully sympathetic to anyone, with women being statistically more likely, ending up leaving academia for this reason. There just aren’t any good solutions. All we can do is figure out which one is the least bad for us.