For over 20 years, the Ocean Discovery Lecture Series (formerly the Distinguished Lecturer Series) has brought the remarkable scientific results and discoveries of the International Ocean Discovery Program and its predecessor programs to academic research institutions, museums, and aquaria. Since 1991, over 1,000 presentations to diverse audiences have been made through the Lecture Series.
The Ocean Discovery Lecturers for the 2023-2024 academic year will be:
Planktic foraminifera are single-celled marine protists that create shells (tests) made from calcium carbonate. Their fossil record in the marine realm is superb, and allows for an unprecedented view into the movement of planktic organisms around the world ocean and insight into their evolutionary processes. As such, evolution and extinction events of fossil plankton are used for first-order age control in sedimentary sequences (biostratigraphy). Planktic foraminifera respond to environmental factors, but temperature is the main factor that controls their distribution, dispersal, and diversity through time. As such, this plankton group is incredibly valuable to reconstruct ancient surface ocean currents.
The last ~23 million years of Earth’s history, the Neogene and Quaternary periods, features a large increase in planktic foraminiferal diversity, and is the time in which surface ocean circulation came into its modern configuration. This time also includes warming events that are analogous to anthropogenic warming modeled for the coming decades, as well as times of global cooling and ice growth. The Neogene and Quaternary periods are therefore ideal periods of time to study the factors that influence plankton evolution and dispersal across the oceans.
Using data from seventeen previous scientific ocean drilling expeditions, combined with new data developed for Ocean Drilling Program Leg 198 in the northwest Pacific, this study investigates the global movement of planktic foraminiferal through the last 23 million years of Earth’s history. Using global occurrences of the planktic foraminiferal genus Globoconella, the processes that allow for bi-polar distributions (occurrences in the poles but not in the tropics) of species will be investigated, as will how species have dispersed from one ocean basin to another. Such dispersal processes also have implications for use of foraminifera in biostratigraphy. The study finds large diachroneity in species’ first and last occurrences due to oceanic and climatic factors. Such diachroneity should be viewed as a strength, rather than a weakness, of the planktic foraminiferal fossil record.
Dr. Adriane Lam received her B.S. from James Madison University, her M.S. from Ohio University, and her Ph.D. from University of Massachusetts Amherst. Adriane joined Binghamton University as a Postdoctoral Fellow in 2020, and began her career there as an Assistant Professor in the Geology Department in 2023. Adriane works with fossil marine plankton and invertebrates to investigate evolutionary processes of these organisms across major climate perturbations. She also conducts paleoceanographic research, where she reconstructs surface ocean currents across ancient warming events that are analogous to the warming Earth is experiencing today and in the coming decades. Adriane is co-creator and co-President of Time Scavengers, a non-profit organization that provides accessible information about climate change and evolutionary theory to aspects of the general public, and helps support the next generation of Earth stewards. Adriane has participated in International Ocean Discovery Program Expeditions 371 (southwest Pacific Ocean) and 393 (southwest Atlantic Ocean).
Contributions from the IODP span a remarkable range of disciplines, from paleoclimate to petrology and from microbiology to mass wasting, to name just a few. Successes of the program have inspired legions of international scientists, making IODP one of the most successful engines of knowledge growth in the last half century. My presentation aims to highlight a little bit of science and quite a bit about the conditions that enabled it. It will be a glimpse under the hood. The science is a vignette of subduction zone behavior elucidated by drilling at the Nankai trough. The work highlights the exceptionally high-quality core that is a hallmark of IODP and that it was essential to revealing changing coupling conditions across a boundary known to produce M8+ earthquakes.
After the science vignette I will zoom out and share my observations of how IODP works both in science terms and more broadly. Themes I’ll discuss include how the science agenda is set, and how early career scientists are recruited and supported. There are many ways for trainees to become part of the community. Finally, I will explore how IODP is influencing the public at large. This part of my presentation will focus on three ways that IODP touches much more than the scientists and scholars that one might expect. First, IODP may well be in a K12 classroom near you, and I’ll describe how that might be the case and how you might participate. Second, IODP has hit the terrestrial highway to great effect. The In Search of Earth’s Secret’s project has brought scientific ocean drilling research to a swath of the US in recent years. Third, IODP has been the breeding ground for what I view as derivative projects that have proven to be very powerful. IODP functions as a STEM-research and learning ecosystem that is truly extraordinary and indeed indispensable for a resilient future.
Jon Lewis is a professor of geology and environment at Indiana University of Pennsylvania where he has been teaching in his undergraduate-only program since 2004. His scholarship focusses on tectonic geology and geoscience community innovations. Most of his recent tectonics work has been in SW Japan, Costa Rica, and Taiwan. In Japan his work has focused on young structures forming in response to plate convergence at the Nankai Trough subduction zone. In Costa Rica he has worked to understand the upper plate structures that are accommodating collision with the Cocos Ridge. In Taiwan he has addressed ongoing arc-continent collision. In the geoscience community realm, since 2016 Jon has co-led the STEM Student Experiences Aboard Ships (STEMSEAS) project, which assembles diverse cohorts of undergraduate students and takes them to sea for transformative experiences on vessels of the U.S. academic fleet for 5-10 days. He is also a co-founding member of the Coastal and Ocean STEM Equity Alliance (COSEA), which is working to support access and belonging for people historically excluded from and/or are not participating in geosciences.
Our current understanding of the long-term carbon cycle holds that Earth’s climate is stabilized by a negative feedback involving the consumption of atmospheric carbon dioxide by the chemical weathering of silicate minerals. This theory posits that silicate weathering responds to climate: when atmospheric pCO2 and surface temperatures rise, chemical weathering accelerates, consuming more atmospheric CO2 and cooling global climate; when pCO2 falls, weathering fluxes decrease, permitting buildup of CO2 and consequent warming. The role that this feedback plays in climate and the carbon cycle has received significant attention, but the implications for the marine silica cycle are relatively less well-studied. Since the release of dissolved silica from chemical weathering reactions is the main input of silica into the oceans, variations in silicate weathering rate in response to trends and perturbations in climate and the carbon cycle must lead to a dynamic marine silica cycle. This inexorably couples the silica cycle to the carbon cycle and global climate. Due to the relatively short residence time of dissolved silica in the oceans, silica burial rates must respond to climate as well. 60 years of deep-sea scientific drilling present the opportunity to probe this dynamic carbon-silica cycle coupling through records of silica burial rates and novel proxies constraining various aspects of the marine silica cycle. In particular, I will present results from recent IODP drilling expeditions to explore the marine silica cycle response to two contrasting Cenozoic warming events: the Paleocene-Eocene Thermal Maximum (PETM, 56 million years ago) and the Middle Eocene Climatic Optimum (MECO, 40 million years ago).
Don Penman holds a bachelors degree in Geology from Carleton College, and a PhD from UC Santa Cruz where he studied the carbonate chemistry response to the Paleocene-Eocene Thermal Maximum with advisor Jim Zachos. He subsequently became a postdoctoral fellow at Yale University and in 2020 joined the Department of Geosciences at Utah State University as an Assistant Professor. Don has sailed on three IODP expeditions as shipboard scientist (342, 371, and 392). His research uses the deep-sea sedimentary record to probe interactions between climate and geochemical cycling during ancient Earth System perturbations.
Windows into the Earth’s subsurface are few and far between. Yet from what glimpses we have had, there appears a boundless capacity for tiny life forms (microbes) to survive, if not thrive, in this vast underground world. However, access to these systems is limited and requires massive engineering and technology efforts to observe. Therefore, we know much less about microbes living down in the dark than their surface counterparts living among us. Through the application of highly sensitive methods at single-cell resolution from a range of subsurface systems, we find these microbes have a massive range in growth rates and cell sizes. They also have the capacity to sustain changing conditions and switch between food sources accordingly. Overall, these investigations improve our understanding of the microbial role in these energy limited environments on Earth, with astrobiological implications for similar systems elsewhere.
Dr. Trembath-Reichert’s research focuses on microbially mediated Earth-life interactions, with the goal of identifying key players in global biogeochemical cycles and determining their rates of activity in past and modern environments. She integrates a range of techniques, including geochemical, gene-based, and statistical methods, and applies them across various scales, from molecules to oceanic basins. She is an Assistant Professor in the School of Earth and Space Exploration at Arizona State University in Tempe, Arizona.
On the day after Christmas, 2004, the world awoke to an immense tragedy – one of the largest earthquakes ever recorded (Mw 9.2) struck Sumatra in Indonesia. In the following hours and days, the tragedy grew as a massive tsunami swept around the Indian Ocean and world, inundating coastal communities with tremendous loss of life.
Our appreciation of the variability of subduction zone earthquakes has grown in the past decades and encompasses non-destructive, slow-slip earthquakes, like those along the Hikurangi margin of New Zealand, and massive, destructive tremors, like the Sumatra earthquake (and everything in between). IODP Expedition 362 sailed in summer of 2016 to evaluate whether the thick sedimentary section subducted at the Sumatra margin consists of materials that through burial and diagenetic processes could contribute to one of the largest earthquakes recorded and rupture the seafloor and trigger a devastating tsunami. We discovered a ca. 1300 m turbidite fan section (Nicobar Fan) dominated by detritus eroded from the Himalayas and deposited within 7 m.y. Early, low-temperature diagenetic reactions (opal transformations) were detected, and burial, thermal, and diagenetic modeling suggest that many diagenetic processes, like smectite-illite transformation, may be advanced by the time the sediments start subduction and may no longer contribute to overpressures created under the rapid loading of subduction. Cementation processes, like quartz cement formation, may also have begun in the section prior to subduction initiation, further contributing to an overall stronger section than found at most subduction margins. These results offer one more constraint on the myriad expressions of subduction zone seismicity.
Peter Vrolijk is an Adjunct Professor at New Mexico Tech and pursues a number of retirement interests, including participation in IODP Expedition 362 and post-expedition research. Following B.S. and M.S. degrees at MIT and a PhD at U. C. Santa Cruz, exploring fluid flow processes in shallow subduction zones, and post-docs at Cambridge University and the Univ. of Michigan, he pursed a research career at Exxon and Exxon-Mobil, retiring in 2016 just in time to join IODP Expedition 362. Throughout his career he has worked on a wide variety of problems, encompassing methods development for fault dating, normal fault processes, and subsurface fluid flow methods, but he has always maintained an interest in subduction zone processes.
In retirement Peter has pursued select research projects that have afforded him the opportunity to support developing student scientists, including the Sumatra expedition and the development of autonomous underwater exploration methods on the Costa Rican subduction margin. In addition, volunteer activities in local wilderness areas and MIT undergraduate student recruitment provide opportunities for fruitful use of retirement time.
The Ocean Discovery Lecturers for the 2022-2023 academic year are:
Reconstructing the climate of Earth’s arid continental regions can be challenging due to a lack of continuous archives. Dust blown from the continents to the oceans carries molecules of land plants and soil bacteria with it, thereby allowing past conditions on land to be studied from ocean sediments. Two regions that receive large quantities of dust are the Atlantic Ocean offshore northern Africa and the eastern Indian Ocean offshore northwest Australia. Scientific ocean drilling has provided sedimentary archives from both regions, allowing for past climates to be studied from the adjacent arid continents. Understanding how Earth’s climate has varied in the past, prior to the influence of human activities, is important for understanding how the climate system works and can provide insights into future climate variability. A time interval of interest is the mid-Pliocene warm period (~3.3 to 3.0 million years ago), when Earth likely had similar atmospheric carbon dioxide concentrations to today.
In 2015, IODP Expedition 356 recovered Plio-Pleistocene sediments from the northwest Australian Shelf. Site U1463 is situated directly underneath the northwest dust pathway, which transports material from central and northwestern Australia offshore. In 1986, ODP Leg 108 recovered Plio-Pleistocene sediments from the tropical eastern Atlantic Ocean. Situated beneath the path of the African Easterly Jet, Site 660 receives dust from the Sahara/Sahel region of central North Africa. At both Sites, branched glycerol dialkyl glycerol tetraethers (GDGTs) produced by soil bacteria are used to reconstruct continental temperature variability. At ODP Site 660, plant wax deuterium and carbon isotopes are also used to examine hydroclimate fluctuations and past shifts in the dominant vegetation type (C3 versus C4 plants), respectively. Plant waxes are also present at Site U1463, but concentrations are generally too low to allow for isotopic measurements. At both Sites U1463 and 660, relationships between continental conditions and sea surface temperature are made by examining alkenone (Uk’37 index) and TEX86 (isoprenoid GDGT) temperature reconstructions from the same samples. These paired continental and marine observations provide insight into the role of ocean warming and cooling in influencing continental climates over the past 4 million years.
Isla Castañeda is an Associate Professor at the University of Massachusetts Amherst with a joint appointment between the Department of Geosciences and Commonwealth Honors College. She received her bachelor’s degree from Syracuse University, her master’s degree from the University of Colorado at Boulder, and her doctorate from the University of Minnesota. As a postdoctoral research associate at the Royal Netherlands Institute for Sea Research, she used organic geochemical and isotopic proxies to investigate the paleoceanographic and climatic history of the Eastern Mediterranean Sea and the southwestern Indian Ocean. In 2015, Isla sailed on IODP Expedition 356; she and her students are currently working on several ODP/IODP Sites including Site U1463 (NW Australia), ODP Site 647 (south of Greenland), Site U1540 (central South Pacific), and ODP 660 (NW Africa). Isla also uses organic geochemical techniques to reconstruct past climate from lakes and is currently has ongoing research on tropical Lake Malawi, artic Lake El’gygytgyn, and several small lakes in southern Greenland.
What controls the long-term trajectory of Earth’s climate and ocean chemistry? How do marine sediments regulate – and bear witness to – these changes? Over the past 50 million years, the Earth has cooled from a “Greenhouse” to an “Icehouse” due to a decline in atmospheric carbon dioxide. Yet, the mechanisms that caused the cooling are still contentious. Examining marine sediment drilled during IODP expeditions allows the exploration of the role of the seafloor in modulating global climate, providing unique perspective on this longstanding debate.
In this talk, I will present a hypothesis supported with empirical evidence that invokes changes in reverse weathering on the seafloor to explain the increase in seawater Mg/Ca and global cooling observed over the past 50 million years. This hypothesis inverts prevailing hypotheses and abundant models that require an increase in silicate weathering as the driver of many elemental and isotopic trends over the Cenozoic. Stemming from this work are avenues of research to reconsider the role of the seafloor in biogeochemical and climate enigmas with implications for Earth’s past, present, and future climate.
Ann G. Dunlea completed her PhD at Boston University with Richard W. Murray, researching biogeochemistry and paleoceanography of pelagic clays from the South Pacific Gyre. She became a postdoc at Woods Hole Oceanographic Institution in 2016 and was hired as an Assistant Scientist there in 2019. Dunlea’s research investigates the diverse and dynamic subseafloor geochemical processes actively interacting with the ocean and long-term changes in climate.
The largest, most powerful earthquakes on Earth occur in subduction zones, where two lithospheric plates converge. Over the past three decades, ocean drilling has greatly advanced our understanding of these great earthquakes and the devastating tsunamis that accompany them, including one in 2004 off Sumatra, Indonesia and another in 2011 off Tohoku, Japan that killed hundreds of thousands of people.
At the Hikurangi convergent margin, also a site of large earthquakes and tsunamis, the subducting Pacific plate has many large and small seamounts and is covered by more than a kilometer of various kinds of sediment. Subduction of the seamounts causes extensive deformation on the overriding plate and may stimulate a special kind of earthquake called slow slip events. I will discuss the results from recent IODP Expeditions and associated 3D seismic reflection data from the Hikurangi subduction margin off NE New Zealand that provide new constraints on these processes.
In late 2017 and early 2018, IODP Expeditions 372 and 375 cored and logged sites on the incoming plate, at the toe of the overriding plate and within a basin landward on the upper plate, and emplaced long-term monitoring equipment in two of those holes. The cores and logs provide detailed information that we can extrapolate widely with a 3D seismic reflection data set that was also collected in early 2018. The 3D data provide knowledge of the oceanic basement and its overlying sediments and how they interact with the overriding plate to potentially cause great earthquakes and tsunamis.
Gregory Moore joined the University of Hawai`i as a Professor in December, 1988 after holding academic positions at Tulsa University and Scripps Institution of Oceanography. He earned a BA at UC Santa Barbara, an MS at The Johns Hopkins University, and Ph.D. at Cornell University. Dr. Moore has participated as a co-chief scientist on ODP Leg 190 and IODP Expedition 338; as a logging scientist on Legs 131, 156 and 172A, and Expedition 358; and as a member of the NanTroSEIZE Project Management Team for 12 expeditions between 2007 and 2019.
Active, young rift systems provide a unique window into the earliest stages of continental breakup, host earthquakes, and other geohazards, and are highly sensitive to environmental change. However, many questions remain about how fault systems accommodate rift opening and evolve over time, and how tectonic- and climate-driven processes conspire to shape rift evolution. Rift basin sediments record basin subsidence and fault slip, surface processes around and within the rift basin, and environmental changes, which can be used to tackle these questions. Here I will summarize new results from the Corinth Rift in Greece and the Malawi Rift in east Africa that provide new insights into these questions.
The Corinth Rift (Greece) is a young rift undergoing rapid extension, and it is one of the most seismically active regions in Europe. The rift hosts semi-isolated basins that oscillate between marine and lacustrine conditions due to sea level fluctuations associated with glacial cycles. Drilling during IODP Expedition 381 recovered rift basin sediments that include a high-resolution record of the last ~780 thousand years and reveal the timing and nature of dramatic environmental changes. Furthermore, integration of drilling and seismic imaging data provide evidence for fluctuations in the rate of sediment delivery to the basin associated with glacial cycles and a marked evolution in the activity of fault systems. I compare the Corinth Rift to Malawi Rift, a land-locked, early-stage rift in the southern East Africa Rift System that has experienced similarly dramatic climate-driven fluctuations in surface processes and an evolution in faulting, as documented by drilling as a part of the International Continental Scientific Drilling Program and seismic imaging.
Donna Shillington is an Associate Professor at Northern Arizona University. She studies tectonic, magmatic, and surface processes at ancient and active tectonic boundaries. She has sailed on one IODP and one ODP expedition and has participated in or led 20 other marine research expeditions and onshore field programs, including to other ancient and active rift systems.
The Guaymas Basin in the Gulf of California is a young marginal rift basin characterized by active seafloor spreading and hydrothermal venting. High plankton production in surface waters and terrigenous sedimentation from the Sonoran mainland combine to rapidly deposit organic‐rich sediments, which are permeated by extensive thermal and geochemical gradients. Deeply emplaced hot volcanic sills extend across the basin and alter the surrounding sediments by transforming buried sedimentary carbon into hydrocarbons, especially methane. The rapid mobilization and re-injection of these hydrocarbons into the biosphere impact the carbon cycle of the basin and provide a model system that illuminates climate perturbations. Subsurface microbial populations potentially intercept and process these hydrothermally generated and mobilized carbon sources, but their depth extent and cell numbers are expected to be controlled by the steep geothermal gradients that are characteristic of Guaymas Basin. Here I will provide an overview on this fascinating hydrothermal geo-ecosystem, and introduce IODP drilling expedition 385 to Guaymas Basin (Sept. 16 to Nov. 16, 2019) with JOIDES Resolution. The expedition scientists and drilling crew recovered 4 km of sediment core and >350 m of sill core from eight drilling sites across Guaymas Basin, measured geothermal gradients in diverse settings ranging from recently emplaced hot sills to cold seep sites, and probed the highly diverse biogeochemistry and microbiology of the Guaymas Basin subsurface sills and sediments. Naturally I am not entirely unbiased, but the expedition has come upon many surprising and unexpected findings that will sustain many years of follow-up research. Highlights will be presented as appropriate for ongoing investigations.
Dr. Teske is a professor in the Department of Marine Sciences at the University of North Carolina at Chapel Hill. His expertise is in microbial ecology and microbial systematics. He is particularly interested in bacteria and archaea of marine environments, like the hydrocarbon-rich Guaymas Basin in the Gulf of California. More specifically, he focuses on understanding the natural diversity of the indigenous microbial communities as well as their environmental tolerances and physiological adaptations. He has been working for many years in a part of the ocean that is involved in the rapid microbial and abiotic hydrocarbon production and consumption. His integrated biogeochemical and microbiological research approach to science explores the pathways of and environmental controls on consumption and production of methane, other alkanes, dissolved inorganic carbon, low molecular weight organic acids and sedimentary organic matter that fuel the Guaymas Basin microbial ecosystem. Dr. Teske has led multiple expeditions with research ship Atlantis and deep-sea submersible Alvin to Guaymas Basin; his most recent project is deep subsurface drilling across this spreading center. He serves on the editorial advisory board of Geobiology, and is chief specialty editor for Extreme Microbiology in Frontiers of Microbiology.
The phrase “the final frontier” has been used to describe both Earth’s seafloor as well as outer space. Scientific exploration of each domain requires tremendous effort, but the former is far more accessible than the latter in terms of cost and resources. As such, scientific ocean drilling, which enables sampling of Earth materials to depths of hundreds of meters to kilometers, presents an exciting avenue for studying processes that have taken place on multiple rocky worlds within our solar system at a scale that cannot currently be achieved with space missions. In this talk, we discuss how scientific ocean drilling can teach us about fundamental planetary processes including impact cratering, plume volcanism, and true polar wander.
In 2016, IODP-ICDP Expedition 364 drilled into the peak ring of the 200 km diameter Chicxulub impact crater (Yucatan Peninsula, Mexico). Chicxulub crater is exceptionally well-preserved compared to similarly large craters on Earth and is therefore an ideal analog for craters that formed on the early Earth and on other planetary bodies. Here we discuss how Expedition 364 has contributed to our knowledge of how large impact craters form and achieve their final structures. We also explore how vast post-impact hydrothermal systems within large craters may evolve into niche habitable environments. We pay emphasis to how paleomagnetism and rock magnetism can be used as a complement to traditional petrographic, structural, and modeling approaches to investigate the aforementioned topics.
This past year, IODP Expedition 391 sampled the Walvis Ridge (South Atlantic Ocean), which includes the Tristan-Gough hotspot tracks. These hotspot tracks were likely produced by plume volcanism, which is the primary mechanism of heat loss on planetary bodies that do not have plate tectonics. We present a preview of how studying the Walvis Ridge will provide insight into plume structure and geochemical evolution, and whether (within the past 100 million years) the Earth has experienced a significant solid-body rotation with respect to its spin axis known as True Polar Wander as Mars and the Moon have done in their pasts.
Sonia Tikoo is an Assistant Professor in the Department of Geophysics at Stanford University. Her research primarily focuses on the application of paleomagnetism to problems in the planetary sciences, including dynamo generation and evolution, geodynamics, and impact cratering processes. Sonia earned her Ph.D. in Planetary Sciences from the Massachusetts Institute of Technology. She served as a paleomagnetist on IODP-ICDP Expedition 364 Chicxulub Impact Crater and on IODP Expedition 391 Walvis Ridge Hotspot.
The application period to host an Ocean Discovery Lecturer is closed.
Information on current and previous Ocean Discovery Distinguished Lecturers can be found here.