Cruise Participants
R/V Knorr 223, October-December, 2014
Atlantic Meriodional Circulation, Last Glacial Maximum
PI’s: Art Spivack, Steve D’Hondt, and Rob Pockalny
Chief Scientist: Rick Murray
Maximiliano (“Max”) J. Amenabar, Montana State University.
Doctoral candidate, specializing in microbial physiology (Advisor: Dr. Eric Boyd) The metabolic processes that sustain microbial life in sub seafloor sediments are poorly described. Here, using cultivation dependent and independent approaches, we will quantify the influence of oxygen penetration on the processes that sustain life in subseafloor sediments. To achieve this goal, I will quantify the abundance of cells capable of coupling the oxidation of a variety of key inorganic and organic electron donors and electron acceptors, including O2, NO3, SO4, Fe3+, and Mn4+. The results of this study will provide key new insight into the extent of life in subseafloor environments and the metabolic processes that sustain this life.
Chloe Anderson, Boston University.
I am one of Rick Murray’s Ph.D students. I am interested in the ferric/ferrous ratios in the sediments to characterize how much Fe could be bioavaiable in the sediments. I will be taking some select samples to analyze with Mossbauer spectroscopy. I am also interested in Mn chemistry in the sediments and porewaters. I have abundant shipboard experience dating from my undergraduate degree and afterward at the University of Washington.
Mike Barber, IUP.
Mike recently returned to academia after doing a lot of other interesting stuff. He’s currently working on a research project related to lava flow identification, chronology, and morphology by means of remote lidar imaging and reflectivity data in the northwest rift zone, Oregon. He’ll finish his degree at IUP this spring and then plans to review his options for the future.
Steve D’Hondt, URI.My research addresses fundamental problems in geobiology, with particular focus on subseafloor life. My students, collaborators and I analyze the composition and diversity of microbial communities in sediment and seawater, document the processes that nourish subseafloor ecosystems, and test the dependence of subseafloor ecosystems on the surface world. In all of these projects, I collaborate with talented people from around the world, including the many scientists and staff members of this expedition.
Sierra Davis, IUP.I am currently a senior undergraduate student at the Indiana University of Pennsylvania (IUP) majoring in geology and minoring in mathematics. Dr. Steve Hovan is my academic and research advisor. My research interests during my undergraduate career have included aspects of geophysics and paleoceanography. This past summer I worked with Dr. Christopher Sorlien through the REU program at the University of Rhode Island doing seismic interpretation. After graduation, my plan is to attend graduate school to pursue a masters or Ph.D., likely in geophysics. This will be my first research cruise – I am excited to meet everyone and to participate in interdisciplinary aspects of marine science research.
Jules Dill, IUP.
I am an undergraduate geoscience student attending Indiana University of Pennsylvania. Currently I am doing research using eolian deposition patterns in the eastern equatorial Pacific as an indication of paleoceanographic conditions during the Middle Miocene. I plan to go to graduate school after finishing my degree.
Ann Dunlea, Boston University.
Most of my PhD research (adviser: Rick Murray) focuses on the provenance of pelagic clays from the South Pacific Gyre (SPG) and the authigenic processes that affect their chemistry. The goal is to characterize the paleoceanographic evolution of the SPG by analyzing the major, trace, REE concentrations of bulk sediment and apply multivariate statistical techniques to partition the sediment into different sources. I’m excited to be coring pelagic sediment in the North Atlantic and, along with the cruise objectives, hope to learn more about the provenance and postdepositional processes affecting this sediment and porewater. I participated recently on IODP Expedition 346 (Asian Monsoon) as well as the Langseth coring cruise to the Line Islands several years ago.
Mary Dzaugis, URI.
I am a graduate student at the Graduate School of Oceanography, URI, working with Steve D’Hondt. I am working on quantifying the hydrogen production through water radiolysis in subseafloor basalt for my PhD. This will be my first coring cruise and I will be working on the ship as a core curator. I am looking forward to learning more about shipboard analysis and coring techniques.
Emily Estes, WHOI.I’m a graduate student at WHOI working with Colleen Hansel on microbe-mineral interactions and carbon cycling. On the cruise, I’ll be collecting samples to look at adsorption of organic matter to mineral surfaces and whether adsorption protects the organic matter against remineralization. To accomplish this, I’ll be analyzing bulk mineralogy and total organic carbon and using spatially resolved techniques such as scanning transmission X-ray microscopy. Scott Wankel at WHOI is helping me with the EA-IRMS for bulk organic carbon, and we work with Dennis Nordlund at Stanford Synchrotron Radiation Lightsource for the NEXAFS analyses. We’ve been having some discussions with other Knorr scientists (Chloe Anderson and Rick Murray, BU) about collaborating in studies of Fe, Mn, and perhaps other redox species in sediment and pore waters.
Dennis Graham, URI.
Lab Manager/Research Technician. I’m just going along for the free food and to ask Rick more questions about buying and owning a sailboat.
Casey Hearn, URI.
I am a second year graduate student at GSO working for professor John King with my primary research interests in coastal paleoceanography. I will be gaining experience with coring site evaluation using shipboard sonar and operation of the core logger. My previous cruise experience has been focused on measurements of conductive heat transfer at the sedimentwater interface using ROV-deployed instrumentation.
Kira Homola, URI.
I am a PhD student at URI, advised by Art Spivack in the BioGeoChemistry group. I am interested in reconstructing salinity and preformed nutrient concentrations of the bottom water at the LGM. This will be achieved through measuring density, dissolved oxygen, and a suit of other geochemical properties at intervals along the cores. These values will act as inputs for post-cruise diffusion modeling, and the determined bottom water values will be used to draw conclusions about the overturning circulation in the Atlantic during the LGM, which is relevant for understanding changes in our current ocean circulation in response to climate change.
Steve Hovan, IUP.
Steve is Chairperson of the Geoscience Department there. His research interests surround the paleoclimatic record of terrigenous inputs to the deep sea, particularly those involving eolian dust transport to map zonal winds patterns and understand how changing wind patterns are related to Earth’s climate system. On the Knorr cruise, he will be working closely with the lithological description team, and helping out with the MST data collection and synthesis as needed. Currently he doesn’t have any plans to work with sediments collected during this expedition, but is happy to help with anyone who has a need for detailed grain size analyses.
Zak Kerrigan, URI.
I am a second year PhD student in the D’Hondt Lab at URI Graduate School of Oceanography. My research is focused on deep-sea microbial genetics in very low nutrient environments and how the genome may change over time. On this cruise I am part of the team collecting samples for all microbiological investigation from both the deep sediment cores as well as the water column. This is my first research cruise and I am excited to be a part of it and gain some insight into the intricacies of deep-sea coring techniques.
Claire McKinley, Texas A & M.
I’m a PhD student with Dr. Debbie Thomas at TAMU. My research focuses on reconstructing the seawater and detrital record of Nd and Pb at the seafloor. Nd and Pb isotopes in seawater are incorporated into the authigenic oxide coatings on sediments and provide a tracer of weathering inputs, the origins of water masses, and their movements. I hope to employ this record to examine the evolution of Atlantic water mass structure during late Paleogene to early Neogene (approximately 50 to 15 million years ago). I did my undergraduate degree at Boston University with Rick Murray as my advisor—despite this experience, I have chosen paleoceanography as a career path.
Rick Murray, Boston University.
I’m a sediment and porewater chemist interested in various aspects of biogeochemistry. Much of my recent work has to deal with provenance of eolian dust and volcanic ash that is dispersed throughout the sediment. This work parallels some longstanding interests in porewater diagenesis and, via leadership from the URI team, the subseafloor microbial system. I’ve been on a lot of IODP cruises, including Expedition 346 (Asian Monsoon) last year and on which I had the pleasure to be Co-Chief Scientist, and several UNOLS cruises, including the Knorr EQP with D’Hondt, Spivack, Smith, Pockalny, Graham, and other members of the extended URI family. Starting in January, I will be the Division Director of Ocean Sciences at NSF for several years.
Rob Pockalny, URI.
I am a Marine Research Scientist at URI/GSO and a co-PI on the project. My general field of specialization is Marine Geophysics, where I use a suite of geophysical data (e.g., bathymetry, side-scan/back-scatter, gravity, magnetics, and seismics) to characterize the processes and 4-D architecture of the seafloor and oceanic lithosphere. My efforts on the cruise will focus on using the geophysical data to best locate the cores required to meet our scientific objectives.
Ted Present, Caltech.
I’m a PhD student working with Jess Adkins. Sulfate is a wellmixed major ion in seawater, but is largely removed by axial (high-temperature) hydrothermal circulation in the form of anhydrite (CaSO4) precipitation in the crust. This flux is assumed to be balanced by dissolution of the anhydrite off-axis. I believe this cruise’s goal to core oxic, thin sediments on crust too old to have active hydrothermal circulation provides an opportunity to quantify the diffusion of this sulfate back into the ocean. I am interested in the net hydrothermal sulfate flux because I study the evolution of Earth’s sulfate budget as a window into biogeochemical redox changes.
Justine Sauvage, URI.
I’m a graduate student working in Steven D’Hondt’s lab. For my dissertation I’m investigating if microbial life can live off hydrogen produced by natural radioactivity in deep subseafloor sediment. For this expedition I’m hoping to use some of the porewater chemistry data to get an idea of what type of microbial metabolisms are being encountered in the targeted sedimentary environments by performing a variety of bio-energetic calculations (e.g. metabolite fluxes, reaction rates and Gibbs energies of reactions).
David Smith, URI.
I am a Professor and Associate Dean at URI’s Graduate School of Oceanography. My general field of research is marine microbial ecology, and I study how microorganisms have evolved to be competitive in the ocean and how their activities at the microscopic scale affect the cycling of elements at the global scale. Currently, my primary focus is on the study of microbial life in deeply buried sediments. My research has taken me to all seven continents as well as the North Pole, and I’ve spent over two years working on research vessels at sea.
Art Spivack, URI.
I am an oceanographer with a background in geochemistry. My research interests span both basic and applied earth science. I conceived of some of the scientific concepts underlying the objectives of this cruise (using pore fluids to reconstruct past nutrient use) during past collaborative work with the co-PI’s of the project (Steven D’Hondt and Rob Pockalny) as well as Rick Murray and David Smith. I enjoy developing new chemical methods that can be used to study questions across disciplines and helping students develop their own research areas.
Nan Xiao, Kochi Core Center, JAMSTEC, Japan.
I’m a microbiologist and my research interest is to understand the microbes buried in the sediments, and to particularly address the questions how many microbes are in the sediments, what they are, are they alive or not. I will bring the sediment samples back to Japan and work with my colleagues for getting answers to these questions.
Sea Change: notes from Researcher Ridge 