For more than 30 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, more than 1,000 presentations to diverse audiences have been made through the Lecture Series.

The Ocean Discovery Lecturers for the 2025-2026 academic year are:

MAGNETIC FORENSICS IN THE SCOTIA SEA: EXPLORING THE DEEP SEA MAGNETIC SUSCEPTIBILITY-ICE CORE DUST CONNECTION

 

For more than 50 years, international collaborative scientific ocean drilling programs have recovered long sedimentary records from the world’s oceans that serve as recorders of Earth’s complex history. Scientific ocean drilling records have advanced understanding of Earth’s climate and the interconnectedness of its wind systems, ocean currents, and ice sheets. A decades-old puzzle concerns the cause of the striking similarity between late Pleistocene sedimentary magnetic susceptibility records from the Scotia Sea, Southern Ocean, recovered from 3700m below sea level, and atmospheric dust flux records constructed from East Antarctic ice cores recovered from 2900m above sea level. The Scotia Sea is down-wind of a modern dust plume emanating from southern South America, and Patagonia has been geochemically fingerprinted as the source of Late Pleistocene dust in East Antarctic ice cores. However, dust is typically a minor contribution to marine sediment and may not be voluminous enough to drive the susceptibility signal of glacial-marine sediments. Here we present results from International Ocean Discovery Program Expedition 382 to “Iceberg Alley” in the Scotia Sea. In this presentation, I examine time slices across the Pleistocene to conduct “magnetic forensics” by characterizing the magnetic mineral assemblages responsible for the Scotia Sea magnetic susceptibility signal, and compare these with magnetic provenance data from glacial outwash in southern Patagonia and terrestrial and marine till and bedrock from the Antarctic Peninsula, West Antarctica, and East Antarctica. I explore the roles of Antarctic Ice Sheet grounding line locations, the sources of silt supplied to the Southern Ocean, and subsequent redistribution by deep ocean currents to understand linkages between the Antarctic Ice Sheet, southern westerly winds, the Antarctic Circumpolar Current, and Weddell Sea Gyre during the Pleistocene.

Dr. Stefanie Brachfeld is the Vice Provost for Research at Montclair State University and a Professor in the Department of Earth and Environmental Studies. Dr. Brachfeld’s research expertise is in marine geology, Antarctic System Science, paleoclimatology, paleomagnetism, environmental magnetism, and planetary magnetism. She has participated in 11 marine geology and geophysics and paleoceanographic expeditions to Antarctica, the North Atlantic Ocean, and Arctic Ocean, including two expeditions aboard the JOIDES Resolution. Dr. Brachfeld has served as an invited member of advisory boards for multiple national facilities and programs including the Institute for Rock Magnetism, Antarctic Marine Geology Research Facility, U.S. Polar Rock Repository, Antarctic Research and Supply Vessel Scientific Advisory Committee, and the Polar Subcommittee of the Advisory Board to the NSF Geoscience Directorate. She currently chairs the Science Communication subcommittee of the U.S. Advisory Committee for Scientific Ocean Drilling (USAC). Dr. Brachfeld is especially proud of her 70+ Montclair State University student advisees who are now gainfully employed as environmental professionals, geoscientists, K-12 educators, education and outreach specialists, government employees, postdocs and research scientists, professors, and those pursuing advanced degrees. 

MARINE TEPHRA RECORDS TELL BIG STORIES—HIGHLY EXPLOSIVE VOLCANISM AND RIFTING IN PARADISE (THE HELLENIC ARC, GREECE)

  

The Hellenic arc in Greece is the most active volcanic region in Europe, posing hazards that range from tephra fall to pyroclastic flows that travel across both the seafloor and the sea surface, and resulting tsunamis. The most famous eruption in the Christiana-Santorini-Kolumbo (CSK) volcanic field within this arc is the 1600 BCE caldera-forming eruption of Santorini that buried a thriving Bronze Age city and caused widespread tsunamis. The most recent explosive eruption is the ~400-year-old eruption of neighboring Kolumbo volcano, but islands within the Santorini caldera have erupted as recently as 1950. The CSK volcanic field sits within an active submarine extensional basin whose sediments preserve the entire tephra record of the arc since its initiation. IODP Expedition 398 sampled this uninterrupted record of volcanism at twelve sites within the volcanic field, providing an unprecedented opportunity to develop a robust record of hazardous events for volcanic risk assessment. We are also sampling the crystal cargo in particularly noteworthy tephra events to develop conceptual models for magma storage regions and eruption triggers, and how those have changed over time. The record is also being used to decipher long term links between volcanism and tectonics.

There are many exciting and sobering outcomes of Expedition 398, including the recognition of a previously unknown submarine explosive eruption of ancestral Santorini based on our sampling of giant offshore pumice deposits. This submarine deposit volume is six times bigger than the late Bronze Age Santorini eruption, the largest in the region. Pyroclastic flow deposits reached land 30km away. Another previously unknown tephra deposit within Santorini’s caldera provides evidence for an explosive eruption from Kameni volcano in 726 CE. Effusive eruptions from this caldera volcano are well known as recently as 75 years ago, but this VEI 5 eruption exceeds previously considered worst-case scenarios. Other notable expedition outcomes include good matches between seismic and petrologic models for Kolumbo volcano magma storage, the recognition of a far-traveled ash megabed originating from the Kos Plateau >120km away, and documented linkages between crustal faulting/rifting events and volcanism.

Dr. Susan DeBari is professor emerita in the Geology Department at Western Washington University. She received her B.A. in Geology from Cornell University and her Ph.D. from Stanford University. Susan started her geological career as a field geologist working on uplifted deep crustal sections of ancient volcanic arcs. Over the years, that research focus gradually shifted to the opposite end of the volcanic system, using eruptive products from active volcanoes to better understand hazards. Her current research focus is on the use of crystals carried by tephras and lavas from active volcanoes to decipher their subvolcanic architecture and eruption triggers. She began marine research over 30 years ago with dives into the Izu Bonin trench with the Shinkai submersible and was a co-proponent on several IODP drilling proposals in that arc system. She sailed on her first IODP expedition in 2014, and then again on the Hellenic arc expedition in 2022-23. She will highlight the impressive outcomes that can be fostered by the unique opportunity of multidisciplinary and international collaboration on an IODP research vessel.

STORIES OF COMMUNICATING SCIENTIFIC OCEAN DRILLING, FROM TEXT TO TEXTILES

 

Starting with the very first scientific oceanographic research expedition, scientists in this field have been sharing their discoveries with wide-ranging audiences. Tales of adventures at sea are disseminated in the popular press (social media, magazines, books, etc.), while the completed analyses of deep-sea samples are published in scholarly reports and peer-reviewed journals. This presentation will highlight specific examples of how scientific ocean drilling expeditions have been shared from CUSS 1 (Project Mohole), Glomar Challenger, and JOIDES Resolution. A spotlight will be placed on DSDP Leg 3 from 1969, the expedition that provided the evidence for plate tectonics, and IODP Expedition 390, which visited the region just over 50 years later and on which I sailed in 2022 as an Onboard Outreach Officer.

In addition to sharing the process of science at sea through social media, daily geospatial updates, blog posts, and Zoom sessions, I have continued disseminating stories post-expedition through audio narratives and the generation of a quilt collection that includes data visualizations and gamified tapestries. This presentation will include audio clips from scientists that sailed on early and more recent scientific ocean drilling expeditions, exemplifying their experiences with ship-to-shore communications and access to global news. Select quilts from the Stories of the South Atlantic (IODP Exp. 390) collection will also be showcased at the talk.

Distinguished Professor Laura Guertin holds a Ph.D. in Marine Geology & Geophysics from the University of Miami’s Rosenstiel School of Marine & Atmospheric Science and a B.A. in Geology from Bucknell University. She has served as an Earth Science faculty member at Penn State Brandywine since 2001, where she teaches introductory-level geoscience courses for non-STEM majors. Dr. Guertin has received funding from the EPA and has been a PI/co-PI on several NSF projects relating to geoscience education and outreach. Her teaching has been recognized with awards from the Geological Society of America and Association for Women Geoscientists. Other national recognitions include being named a Fellow of both the Geological Society of America and the American Association for the Advancement of Science, receiving a U.S. Senate Certificate of Special Recognition, and named as a U.S. Congressional Citation Honoree for her work in the area of civic and community engagement. In addition to sailing on two NOAA vessels and JOIDES Resolution, Dr. Guertin has a passion for sharing scientific research and the process of science with all audiences. Her science communication experiences include serving as the geoscience education and educational technology blogger with the American Geophysical Union for nine years, initiating and managing the growing scientific ocean drilling audio archive Tales from the Deep, and quilting science stories, including a 19-quilt collection from IODP Expedition 390 (https://www.sciodquilts.studio/).

  

LECTURE SCHEDULE

  • September 5, 2025 — Florida International University, Miami, FL
  • September 24, 2025 — Savannah State University, Savannah, GA
  • October 24, 2025 — University of Nebraska Lincoln, Lincoln, NE

RECONSTRUCTING EARLY CENOZOIC CLIMATE AND ATMOSPHERIC CO2 WITH BAYESIAN FORWARD PROXY SYSTEM MODELS

Sedimentary geologic archives reveal Earth underwent many episodes of long-term (millions of years) and short-term (thousands of years or less) warming throughout its geologic past. This includes a prominent interval in the relatively recent late Paleocene and early Eocene from approximately 59 to 50 Ma during which background surface temperatures rose gradually as Earth was peppered by abrupt warming events called hyperthermals. These events are associated with the release of 13C-depleted carbon to the ocean and atmosphere from sedimentary reservoirs and/or volcanism. Thus, hyperthermals including the largest of the interval, the Paleocene Eocene Thermal Maximum, or PETM, provide useful analogues for investigating climate and carbon cycle feedbacks and ground-truthing theory.

Geochemical proxy systems allow for the quantification of past environments, providing insights into the sensitivity of Earth’s surface conditions to past carbon release. Marine archives including biogenic carbonate and organic carbon fossils provide perhaps the most robust resource for reconstructing the environment due to the sensitivity of fossil material to physiochemical conditions, the ubiquity of fossil material, and continuity of deposition provided by the pelagic ocean. Traditionally, environmental reconstructions use inverse proxy models in which environmental variables (e.g., temperature, salinity, [CO2]) are computed from individual proxy measurements (e.g., foraminifera δ18O, Mg/Ca, δ11B) in isolation. However, paleo-proxy systems are complex, and nearly all measurements are dependent on more than one physiochemical variable. Here, I introduce a forward way of thinking about paleo-environmental reconstruction that leverages Bayes’ Theorem. This forward approach represents processes that influence fossil geochemistry as they are in nature, allowing for straightforward integration of multiple proxy systems (and archives) in a single model. I use this approach to interpret past surface temperatures and atmospheric CO2 concentrations from foraminifera proxy measurements over the long-term late Paleocene to early Eocene, and higher-resolution PETM, from North Pacific (ODP Leg 198) and South Atlantic (ODP Leg 208) sediments. I explore the implications of these reconstructions on 1) long- and short-term climate sensitivity and drivers, 2) PETM hydroclimate, and 3) the PETM carbon source in the context of recent IODP Exp. 396 discoveries of PETM-aged hydrothermal vent complexes in the North Atlantic.

Dr. Dustin Harper is a post-doctoral researcher at the University of Utah, where he is part of the Spatio-Temporal Isotopes Analytics Lab (SPATIAL) and CO2 Proxy Integration Project (CO2PIP), working in part to develop Bayesian proxy system models for quantitative CO2 and environmental reconstruction. He received his B.S. and M.S. from UC San Diego and completed his Ph.D. at UC Santa Cruz in 2018. Dustin is an experienced analytical geochemist and statistical model developer focused on carbon cycling during Cenozoic warm periods. He works on both terrestrial and marine proxy systems and has sailed twice on the JOIDES Resolution as a stratigraphic correlator and sedimentologist for IODP Expeditions 371 and 396, respectively.

EARTH’S FIERY PAST: LARGE IGNEOUS PROVINCES, ANOMALOUS CO2, AND THEIR ENVIRONMENTAL IMPACTS

Large igneous provinces (LIPs) are among the most influential drivers of global Earth system changes. These massive volcanic events are linked to extreme climate and ocean conditions, increasing global temperatures, ocean acidification, and widespread marine anoxia. ​​Their emplacement and CO2 release frequently align with some of Earth’s most rapid environmental shifts, including four of the five major mass extinctions—most notably the End-Permian extinction, the largest of the Big Five—highlighting their critical role in past Earth systems transitions. However, studying LIPs—particularly submarine ones—remains challenging, as much of their eruptive material is buried beneath the ocean or has been subducted over time. Consequently, much of our understanding of these events has often relied on sedimentary geochemical proxies. These proxies, including osmium isotopes, mercury concentrations, and carbonate dissolution patterns, have become essential tools for reconstructing LIP emplacement and assessing its impact on the global carbon cycle. They also help establish the timing and intensity of volcanic activity in relation to major climate events.

Scientific ocean drilling has been instrumental in advancing our understanding of LIP-driven environmental change by providing high-resolution sedimentary records from major ocean basins. These records have helped establish spatial and temporal constraints, revealing direct links between LIPs and dramatic climate and ecological disruptions.

In this lecture, I will present findings from multiple IODP expeditions that illustrate the connections between large-scale volcanism, rapid climate shifts, and global biogeochemical cycling. I will discuss new insights into OAE 1a and the Ontong Java Plateau from ODP Leg 198, and explore the influence of LIPs on the Miocene Climatic Optimum using records from ODP Leg 165. Additionally, I will highlight proxy calibration efforts using sediments recovered from IODP Expedition 397. By integrating these records, I will demonstrate how LIPs have shaped past environmental change and explore their broader implications for Earth’s present and future climate dynamics.

Dr. Lucien Nana Yobo is an Assistant Professor in the Department of Geology & Geophysics at Texas A&M University. His research focuses on the application of metal isotopes on multiple aspects of biogeochemistry of past Earth system perturbations, including fingerprinting the effects of large igneous provinces and their extreme environmental impacts.  He has participated in two IODP expeditions, sailing on Expedition 397 and a shore base participant on Expedition 392. He completed his Ph.D. from the University of Houston, following undergraduate studies at California State University-Fresno and graduate work at the University of Nebraska-Lincoln.

A MICROFOSSIL HISTORY FROM THE BOTTOM OF THE SEA: SHARKS, FISH, MASS EXTINCTIONS, AND 85 MILLION YEARS OF GLOBAL CHANGE

 

Fish are the most diverse group of vertebrates on the planet today, and the type and abundance of fish present in the marine ecosystem depend on the environmental conditions and food web processes in that region. Further, fisheries and fish-centric eco-tourism support multi-hundred billion dollar industries, and fish are a significant source of protein for much of the world’s population. Yet our understanding of the development of this spectacular biodiversity, and how fish respond to changes in climate, habitat, and environment, is limited due to their sparse body fossil record. Ichthyoliths—isolated microfossil fish teeth and shark scales—are the most numerous vertebrate fossils known, and preserve a unique history of the abundance, community composition, and evolutionary history of fish and sharks. While most scientific ocean drilling research has focused on paleoclimate reconstructions and plankton evolution, ichthyoliths preserved in these sediments can provide a unique snapshot into the evolutionary and ecological history of marine predators. In this talk, I draw on the 55+ year legacy of interdisciplinary and collaborative foundational work supported by scientific ocean drilling and use ichthyoliths preserved in deep-sea sediments to explore how open-ocean fish and sharks respond to Cretaceous and Cenozoic global change, from mass extinctions to rapid climate change events, and discuss how these upper trophic level marine vertebrates interact with the dynamic earth system.

Dr. Elizabeth Sibert sailed on JOIDES Resolution Expedition 378 and is an Assistant Scientist at Woods Hole Oceanographic Institution. Her research lies at the intersection of biological oceanography and paleobiology, investigating how marine ecosystems, and particularly fish and sharks, interact with global change on short and long timescales, reconstructing ancient marine community dynamics using microfossil fish teeth and shark scales preserved in deep sea sediments. Elizabeth received her B.S. in Biology from UC San Diego, and her M.S. and Ph.D. in Biological Oceanography from Scripps Institution of Oceanography. Following her Ph.D., she was a Junior Fellow in the Harvard Society of Fellows at Harvard University. She subsequently held positions as a Hutchinson Fellow and Associate Research Scientist at Yale University before moving to Woods Hole Oceanographic Institution as an Assistant Scientist, where she is thrilled to support the Paleo-FISHES lab. In addition to her oceanographic research, Elizabeth is passionate about improving access to STEM research to folks with disabilities through research opportunities, career development, and outreach efforts. In her spare time, Elizabeth is a professional-level circus artist and coach, a skill set she has been refining for over 20 years.

Ocean Discovery Lecturer Specifications

  • Six Ocean Discovery Lecturers are chosen for each academic year.
  • Each Ocean Discovery Lecturer is requiredto give six lectures during the academic year. Due to the popularity of the program, many lecturers, however, agree to give more.
  • The lecture topic should focus on results of IODP research. Synthesis lectures on broad topics associated with IODP’s scientific objectives (environmental change, processes, and effects; climate change; deep biosphere and the subseafloor ocean; and solid Earth cycles and geodynamics) are strongly encouraged.
  • Lectures should be aimed at a broad geoscience audiences consisting primarily of graduate and undergraduate students and the scientifically literate public.
  • USSSP will fund the speaker’s transportation expenses to and from each institution; host institutions will provide housing, meals, and local transportation for the speaker.
  • After completion of the required lectures, USSSP will provide a small honorarium for the speaker’s participation.

Host A Lecture

The period for applying to host a 2025-26 Ocean Discovery Lecturer has expired.

Previous Distinguished Lecturers

Information on previous Ocean Discovery Distinguished Lecturers can be found here.