Candidate Statement

Candidate Statement

Name:

I am applying to the Ph.D. program at the University of Maryland, College Park, to further my academic interest in the broad field of geochemistry, learn new skills relevant to my interests, and enhance my research acumen overall in the process.

I have had a keen eye towards the sector of geochemistry ever since the very introduction to its underlying foundations. Chemistry has always been a strong suit in my secondary studies, and Geology gave me a drastic overview of the functioning of earth as a system. Geochemistry seems like a beautiful marriage of both these topics on the whole. Although the fundamentals of geochemistry, including the tenets of cosmochemistry and igneous geochemistry, were fascinating, my deep-seated interest was always in the field of low-temperature geochemistry. The range and variety of applications of low-temperature geochemistry make it perfect for conducting a range of studies in various fields. Kerogen and hydrocarbon formation studies, mineral precipitation and weathering studies, sediment diagenesis studies, and hydrologic studies are all major topics in the field of low-temperature geochemistry. My motivation was to learn the nuances of low-temperature geochemistry involved in paleoclimatology and understanding animal lifestyle patterns.

Climate has always been a fascinating subject. It has a compelling influence on human civilization and the landscape of earth as a whole.  Global weather patterns control several variables involved in the earth’s surficial processes. Most typical drastic events on the global scale, such as the ice age, global droughts, and even sporadic natural disasters, are wholly dependent on the ambient climatic conditions. The geological history of planet earth is well documented, from the inception of this very planet to its current volatile state. Unsurprisingly, the climate has continuously been evolving throughout that period as well, in unison with significant events such as the glaciations and deglaciations, the Great Oxidation Event, the evolution of different organisms, the formation of geologic features. While there may not be a direct correlation between the events, climate undoubtedly played a critical role in the events, as mentioned earlier. Counterintuitively, the factors of solar isolation, sea surface temperatures, wind patterns, and often regional events such as mass volcanism and orogeny can influence the climate of a region significantly as well. All-in-all it’s an intricate feedback-mediated system, and I am aiming to understand the inner workings of the climate system and its effects on the human settlement and the environment in the long run.

By the law of uniformitarianism, similar effects of changing climate must be felt on the environment of the recent past. Early world civilizations had also started flourishing during that period, and the volatile climate must have affected the landscape of such civilizations in many different ways. This thought process was my motivation for opting for my Masters’s dissertation thesis, which involved the fields of stable isotope geochemistry and paleoclimate. The topic of my dissertation was “Carbon Isotope Variations in Holocene Sediments from Rann of Kachchh: Climatic Implications,” which was conducted under the guidance of Prof. Anindya Sarkar at IIT Kharagpur. My work constituted the aspects of preparing Rann of Kachchh sediment core samples for bulk carbon δ¹³C values and Total Organic Carbon content. These samples were analyzed using a Continuous Flow-IRMS, and the climatic and environmental changes were reconstructed from the parameters measured along the core profiles. Some insight into the changing economy and lifestyle of the prevalent Indus Valley Civilisation was also gained through this endeavor.

I have also acquired some research experience in the field of low-temperature geochemistry in my internship projects. I worked as a research intern for two months at the National Institute of Oceanography. I worked on the project titled “Laboratory procedures involved in provenance studies by Strontium and Neodymium isotopes,” under the guidance of Dr. Aninda Mazumdar at CSIR-NIO, Goa. My project was mostly involved with the laboratory procedures involving the separation of the elements via column chromatography, using element-specific resins. The samples of interest were from the cores retrieved from the IODP Project, from the Mahanadi river catchment area. I also acquired experience with operating a pre-conditioned Multi-Collector ICPMS. Additionally, I actively took part in developing procedures for getting a sufficient amplitude signal for strontium detection.

A solid background in field studies also supplements my laboratory experiences. I have had extensive experience in field studies throughout my graduate and undergraduate curriculum. I have partaken in a total of five field trips encompassing the genres of structural geology, sedimentology, and economic geology. The field trips have been pivotal to shaping my perspective as a budding geologist, having brought the pages from my textbook to life. It has also endowed upon me invaluable skills of methodical field-based analysis and much practical nous in enhancing my capacity for teamwork and collaboration. These field experiences, in unison with my work in the laboratory, have been to key to enriching my endurance and intellectual capacity. The magnum opus of abilities is expressed in solving the conundrum of deciphering the primary factor affecting the Holocene climate in the Rann of Kachchh during my Master’s thesis. My wholesome research experience in undertaking this project culminated in me being able to work methodically and independently to present a plausible interpretation of the defined problem statement.

I aim to expand the skillset that I have already acquired and added various skills to my repertoire, including programming skills, a broader understanding of analytical instruments, and enhanced field-based studies. I am also looking to enhance my social skills and gather life experiences, which will definitively aid my all-round development.

I am curious to explore and develop the relationships between changes in different geochemical proxies and global climatic changes in association with local environments. There are still several surficial processes occurring on the earth, and related to them are specific events whose in-depth understanding is still is elusive. My ambition is to study these past events and processes and correlate them to changes in the global climatic parameters, such as insolation and monsoon systems, through experimental and modeling endeavors. Additionally, I also have a vested interest in understanding the effect of such changes on early civilizations. Such endeavors can also aid in understanding allusions to changes induced in modern society. Many natural substances, including sediments, rocks, paleosols ice-cores, speleothems, tree rings, and calcite secreting organisms, form repositories of geochemical signals through which these surficial processes and their related changes of the environment can be studied efficiently. Geochemical analysis of the natural substances holds the key to uncover numerous mysteries of the past, and I want to explore all of the repositories mentioned above in my academic future.

Although my overwhelming interest is in paleoclimatology and its related geochemical processes, one of my objectives in academia is to deconstruct the paleoclimate data to understand the forces behind the climate changes and extrapolate the data for future prognosis. Intensive backward modeling is essential to this endeavor. Conventional paleoclimate analyses are intrinsically forward modeled, with our interpretation resulting from observations of natural or empirical phenomena. A simple anecdote from the terrestrial photosynthetic pathways of a plant can be explored to understand the uncertainties involved in such observations. The carbon isotopic fractionations measured from the majority of organic matter result from the various processes in photosynthesis. Firstly the amount of ambient carbon dioxide has to be taken into consideration, as it reflects whether a pumping mechanism was in place through the stomata. Secondly, the major carbon components of the soil also have to be taken into consideration as it is taken in as nutrients through the roof. These are the ambient factors that have to be considered in addition to the carbon chain length of the intermediate compound to the product of cellulose in the photosynthetic pathway, designated C3 and C4, and CAM. Thus, the extensive range in the δ¹³C values observed in these categories of plants.

Similarly, analyzed values of other paleoclimate parameters such as surface temperature, precipitation records are also intrinsically related to such variables. One of the objectives of my modeling endeavors is also to dissociate the fractionation resulting from different ambient conditions and refine the resolution of the past climate records. When devoid of noise from ambient variables, the values can give us a much better interpretation of the past climate and environment and also enhance its value for foreseeing spatial and temporal trends at present.

The Holocene paleoclimate is a point of great interest to me. It was the core topic of my dissertation thesis, and there are still a fair few enigmatic phenomena whose study is yet to be studied in-depth. One such pertinent example is the 4.2 kyr event (also unequivocally known as the onset of the Meghalayan age). Ubiquitous anomalies in the climate have been observed globally between the period of 4.2 kyr to 3.9 kyr B.P. Consequently, significant incursions in the geochemical signals have been observed from a plethora of paleoclimate studies. Although this has been interpreted by many workers to be the result of disrupted atmospheric circulation systems, the reason behind such synchronous disruptions is still in the air.  I want to revisit this problem from the global perspective and develop a model for the climatic changes in the Indian Monsoon Regime. Stable isotopes of Oxygen and Carbon are potent tools for analyzing the paleoecology and paleoclimate of the region. A variety of viable proxies can be utilized for this exercise. Many workers have already conducted studies using foraminifera, lake sediments, and speleothems. However, the best resolution of such studies can be best observed from tree-rings, as evident from numerous studies on this topic. Thus, I would like to include this proxy into my project, if possible. Oxygen isotopic values are seen to vary with the seasonality of monsoon, solar insolation, and atmospheric circulation. At the same time, carbon isotope incursions can correlate to the ecology and hence the mean annual precipitation. The variables can be mechanistically modeled and fitted to equations to extrapolate the climate parameters spatially, as well as temporally, utilizing efficient simulation software. It would give a wholesome idea of the changes in the global forcing through space and time collectively.

Similarly, the history of ancient civilizations in this regime, like the Indus Valley Civilization and Mesopotamian Civilization, can be studied to connect the changes in the climate to socio-economic factors and settlement patterns. It would go a long way in supplementing archaeological findings and aid in a better understanding of the early societal systems and lifestyle of the people from early civilizations.

Even after stating my overwhelming passion for climate science and paleoclimate studies, I still have the interest to develop a multi-faceted approach to my doctoral studies. My interest has been vested towards the field of earth sciences as a whole, and I would be grateful to carry on my career in academia exploring multiple sections of this subject. The varied field of hard rock and soft rock studies have been coalesced to complement each other perfectly. I hope that during my doctoral studies, I get the opportunity to enhance my knowledge regarding these fields related to my research interest, such as high-temperature geochemistry geomorphology and sequence stratigraphy.

Concluding on a personal note, I would have to state that one of my fortes are that I am a  tireless workhorse, and will conduct my research with utmost dedication if the opportunity is afforded to me. I have contacted Prof. Michael N. Evans at the Department of Geology, and have discussed possible projects that I will be able to contribute towards significantly. I have a vision that is very simpatico with Professor’s research area, and I feel that he would be the perfect supervisor for my doctoral studies. My research ideas also involve intensive use of the instruments mentioned above, and I feel that I would be able to apply my skills effectively in your esteemed doctoral program. My future career in academia will pose a challenge that I am willing to embrace with open arms. I am excited to experience life from a different perspective altogether and gather invaluable memories along the way.