Alex Corsello

Alex Corsello, Biology & Earth Sciences Graduate

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Alex at Buttermilk Falls, Ithaca, NY.

Hello! My name is Alex Corsello and I recently graduated from Binghamton University studying Biology and Earth Science. I’m originally from Virginia, but grew up in Katonah NY, about an hour from New York City (yes there are dirt roads). Additionally, I will be staying at Binghamton to pursue my Masters of Arts in Teaching Earth Science. I am a big fan of hiking, running and baking. While not in the lab I have visited over 100 national parks across the United States, ranging from Yosemite to a tiny house on the corner of a street in Philadelphia. 

I am a paleontologist who studies foraminifera, or forams for short, particularly within the Miocene Period (roughly between 5 and 23 million years ago). My research specifically focuses on determining two things. First, where does the foram species Globoquadrina dehiscens live in the water column in a mid-latitude site?  Second, can G. dehiscens be used as an indicator for past ocean temperatures conditions? Samples are taken from cores drilled through the International Ocean Discovery Program, washed and then picked by size for the particular species that I am studying. Then, using the shell of the organism my samples are sent to Hamilton College, where they are analyzed for both oxygen and carbon isotopes. These isotopic ratios help to provide a picture of the temperature of the water where the organism lived and how productivity there was in the region where this was taking place. Thus it becomes possible to reconstruct ocean conditions. The goal of our lab is to help determine how ocean conditions changed in response to various climate variables in the past in order to best predict how they might change again under a warming climate. 

Alex and a class of second graders at Finn Academy in Elmira, NY, where he conducted an outreach program with the students.

I have always been a bit of a nature nerd… I went to ecology camp starting in first grade. But growing up I always thought I would be a historian. This changed when I took Biology in high school and I became fascinated with how life works. Every part of life, even if it seems really distant, is connected in some way and I think that’s really cool. I started as a Biology major and after taking my first geology class as part of my Biology degree I was hooked. I have been working on earth science research ever since. My favorite part of science is getting to tackle real world problems and to try to make a positive difference for others through your work. You never know what idea could be the key to a big discovery or the tool that solves a pressing problem. There is also something incredibly magical about getting people interested in science. The excitement that comes with learning is infectious and watching those who may have previously been adverse to science start to connect is really powerful. 

Alex presenting his research in poster format the Joint Southeastern/Northeastern Geological Society of America meeting in Reston, VA.

Take risks- That seemingly crazy idea that you came up with while on the toilet at 3 am may help define your path. A lot of the time, yeah, you’ll fail. But it is those few experiences where you succeed that can help to define your path both as a scientist and human being. They are what lead to more opportunities and a whole host of new people and places. Also don’t be afraid to use your resources. There are people who are in your corner who will be there to advocate for you. Don’t be afraid to get their help. You will be much better off for it.

363: Western Pacific Warm Pool

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The sites drilled as part of IODP Expedition 363 in the western Pacific warm pool region of the western equatorial Pacific ocean. Sites are denoted by yellow dots. Figure from IODP 363 Summary.

El-Niño is a phenomenon that occurs in the equatorial Pacific Ocean, causing a short-term shift in  global weather dynamics  around the world. El-Niño involves weakening of the trade winds, which usually push warm surface waters from the eastern equatorial Pacific to the western equatorial Pacific. Such weakening of the trade winds leads to warmer waters to occur in the eastern equatorial Pacific, when there is usually a ‘tongue’ of  cold water at the surface ocean in this region. The rate of change in ocean temperatures, which is the driver of much of the global weather effects associated with El-Niño, have changed alongside global climate dynamics. Every few years, the wind patterns across the equatorial Pacific change, sometimes also shifting to a La Niña phase. The La Niña phase includes strengthening of the trade winds, which leads to even more warm water piling up in the western equatorial Pacific, and cooler waters to appear in the eastern equatorial Pacific. Preliminary studies show that the amount of time between La-Niña and El-Niño conditions are shifting over geologic time. A separate process affected by ocean surface water temperatures in the southeastern Asia region are the Australian Monsoons. These monsoons come off the Indian Ocean and provide rainfall to a significant portion of the northwestern Australian continent. There are two seasons in monsoon climates, a rainy season where moisture laden air moves over land, and a dry season where dry air moves over the oceans. Figuring out how both global and local processes based in the southeast Pacific  are affected by warming oceanic conditions will play a large role in understanding climate change in the future. 

The El-Niño Southern Oscillation pattern in the Pacific Ocean versus the Pacific Ocean in a year under normal conditions.

The best way to study how the climate system interacts with El-Niño conditions is to look at the past. A prime example is the Middle Miocene, a time period of warming occurring 15 million years ago. The warming patterns of the Middle Miocene are similar to warming trends that are seen today, and thus represent a clear example of how carbon dioxide (a greenhouse gas) changes in the atmosphere can influence global sea surface trends. 

Expedition 363 took advantage of the geologic record of sediments in the western equatorial Pacific to reconstruct the La Niña and El Niño phases of the geologic past. The goal of Expedition 363 was to determine how different climate variables changed in the Western Pacific Warm Pool, the pile of warm water in the western equatorial Pacific. Of particular importance was to determine how these changes related to global climate change through the mid-Miocene to the mid-Pleistocene (~15 to 3 million years ago). More specifically, the expedition wanted to determine how  shorter scale climate variability across a millennium. Particularly the study looked at the balance between El-Niño and La- Niña conditions, which can be correlated to previously obtained data on climate and greenhouse gas emissions. Additionally this expedition focused on understanding the history and variables that affect the Australian Monsoon cycle. 

An illustration of La Niña Conditions over the eastern to western equatorial Pacific Ocean. During La Nina conditions, the trade winds strengthen, pushing warm surface waters from the eastern equatorial Pacific to the western equatorial Pacific. Figure from the National Oceanic and Atmospheric Administration.

Sediments recovered during Expedition 363 will allow for a better understanding of the Middle to Late Miocene Periods. Additionally it will allow for a better understanding of the Australian Monsoon system. Geochemical analyses  from this site shows that mixed layer surface ocean temperatures did not cool over time, while subocean temperatures cooled significantly suggesting a change to more overall La-Niña conditions over time. Additionally, maximum greenhouse gas emissions coupled with peak insolation for the Southern Hemisphere provided the shortest Australian Monsoon season. Thus future predictions in a world with increased carbon dioxide levels and warming, would suggest that given rising global temperature a shorter monsoon season would occur.

References

Rosenthal, A.E. Holbourn, D.K. Kulhanek, I.W. Aiello, T.L. Babila, G. Bayon, L. Beaufort, S.C. Bova, J.-H. Chun, H. Dang, A.J. Drury, T. Dunkley Jones, P.P.B. Eichler, A.G. Fernando, K. Gibson, R.G. Hatfield, D.L. Johnson, Y. Kumagai, T. Li, B.K. Linsley, N. Meinicke, G.S. Mountain, B.N. Opdyke, P.N. Pearson, C.R. Poole, A.C. Ravelo, T. Sagawa, A. Schmitt, J.B. Wurtzel, J. Xu, M. Yamamoto, and Y.G. Zhang. (n.d.). Expedition 363 summary. https://doi.org/10.14379/iodp.proc.363.101.2018

Pei, R., Kuhnt, W., Holbourn, A., Hingst, J., Koppe, M., Schultz, J., Kopetz, P., Zhang, P., & Andersen, N. (2021). Monitoring Australian Monsoon variability over the past four glacial cycles. Palaeogeography, Palaeoclimatology, Palaeoecology, 568, 110280. https://doi.org/10.1016/j.palaeo.2021.110280

Steinthorsdottir, M., Coxall, H. K., De Boer, A. M., Huber, M., Barbolini, N., Bradshaw, C. D., Burls, N. J., Feakins, S. J., Gasson, E., Henderiks, J., Holbourn, A. E., Kiel, S., Kohn, M. J., Knorr, G., Kürschner, W. M., Lear, C. H., Liebrand, D., Lunt, D. J., Mörs, T., … Strömberg, C. A. E. (2021). The miocene: The future of the past. Paleoceanography and Paleoclimatology, 36(4). https://doi.org/10.1029/2020PA004037

Microfossils that were contained within the sediments retrieved during Expedition 363. The chemistry of these fossils’ shells, or tests, can be used to reconstruct ancient ocean conditions. Image from the LIMS database.

 

318: Wilkes Land Glacial History

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While the South Pole is covered by a glacier today, the South Pole was not always a frozen wasteland. Glaciation only started about 34 million years ago. As global temperatures changed throughout geologic history,  the amount of ice covering Antarctica changed with it.  As carbon dioxide (a greenhouse gas) amounts have increased and decreased in the atmosphere throughout history, the amount of ice has also fluctuated, so understanding ice flow through geologic time provides a picture of the impact of changing temperatures. It is particularly important to understand how anthropogenic warming has affected rapid ice melting in polar regions. Global carbon dioxide levels are increasing today in amounts not seen in the geologic past . The most recent time interval that had comparable atmospheric carbon dioxide levels occurred 17–15 million years ago, when the earth last warmed. Thus to best understand the future, it is imperative to understand the past and how Earth systems behaved or responded to increased greenhouse gasses in the atmosphere.

A map of the different locations drilled during Expedition 318 off the coast of Antarctica. Drill locations are denoted by the red dots. Obtained from  Integrated Ocean Drilling Program Expedition 318 Summary

Integrated Ocean Drilling Program Expedition 318 focused on the Wilkes Land Ice Shelf, located on the eastern half of the Antarctic continent. The purpose of the expedition was to drill into the ice sheet to understand how much ice melt occurred, and the rate at which it occurred throughout the past 34 million years. In understanding the rate of ice melt it becomes possible to correlate carbon dioxide levels and accompanying temperature increases in the recent past with ice melt and growth. Additionally, another objective of  the mission was to understand how phytoplankton (marine photosynthesizers) have changed through the Holocene (~117 thousand years ago to today). Understanding these changes can provide some insight into how biologic life has changed throughout recent geologic history, particularly in response to changes in the glacial ice.

The change in global temperature in the past 80 million years in relation to ice sheet activity. Time in millions of years is on the left side, and change in global temperatures (in degrees Celsius) is on the bottom axis. The left panel indicates the amount of temperature change through time with major biotic (e.g., extinction of the dinosaurs) and abiotic (e.g., first Antarctic ice sheet) denoted. Right panel indicates how warm the Earth was. Greenhouse world indicates an Earth that had very little to no ice sheets at either of the poles; Transitional world indicates a time when the Earth began to cool down and ice sheets began to appear; Icehouse world was a time when persistent ice sheets were at the South and then the North poles. Obtained from Integrated Ocean Drilling Program Expedition 318 Summary

Results from this expedition were found to be quite alarming. Scientists found that global ice amounts increase and decrease with global carbon dioxide concentrations respectively. This conclusion supported the hypothesis made by scientists that the amount of carbon dioxide in the atmosphere is tightly correlated with the amount of ice melt that is occurring into ocean waters. However, most alarmingly the rate of ice melt exceeded predictions, showing that global sea level rise may occur faster than previously expected. 

References

Gulick, S., Shevenell, A., Montelli, A. et al. Initiation and long-term instability of the East Antarctic Ice Sheet. Nature 552, 225–229 (2017). https://doi.org/10.1038/nature25026

Expedition 318 Scientists, 2011. Expedition 318 summary. In Escutia, C., Brinkhuis, H., Klaus, A., and the Expedition 318 Scientists, Proc. IODP, 318: Tokyo (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.318.101.2011