A distinct, mid-Cretaceous black shale layer, discovered in large swaths of the global ocean during pioneering ocean drilling in the 1970s, represents the effects of severe ocean anoxia approximately 94 million years ago during an event called Oceanic Anoxic Event 2 (OAE2). This intriguing finding that past ocean basins were abruptly deprived of dissolved oxygen has spurred decades of research focused on both the triggers and paleoceanographic responses for this and other Cretaceous OAEs. This lecture will detail key research breakthroughs in the scientific understanding of Cretaceous OAEs over the nearly 50 years since their initial discovery, incorporating the most recent findings from scientific drilling in the Indian Ocean by the JOIDES Resolution research vessel. Geochemical data and sedimentological observations will be presented from cores drilled in the Mentelle Basin (offshore Australia) during International Ocean Discovery Program (IODP) Expedition 369. Observations and data from these cores provide a new understanding of the role and intensity of ocean acidification during OAE2 caused by abrupt CO₂­ emission from the eruptions of large igneous provinces (LIPs). The precise source of the CO₂ remains unclear given uncertainties regarding the ages and eruptive histories of many submarine LIPs. Yet expeditions to recover cores from submarine LIPs, including the most recent Cretaceous IODP expedition which cored the expansive Agulhas Plateau offshore South Africa, provide rare opportunities to help determine which specific LIP so drastically influenced Earth’s climate and oceans in the mid-Cretaceous.

Marine drilling records of the Cretaceous OAEs provide some of the best geologic records of the effects of rapid carbon emission on the ocean-atmosphere system. These records highlight the apparent sensitivity of Cretaceous oceans to the volcanogenic emissions of volatiles like CO₂ and SO₂. However, the natural feedback mechanisms that eventually sequestered carbon to restabilize oceanographic conditions by the end of OAE2 may provide prescient models for modern, geologically-based mitigation strategies to address rising anthropogenic CO₂ levels.

LECTURE SCHEDULE

• November 10, 2023 – Texas A&M University, College Station, TX
• November 29, 2023 – University of Maine, Orono, ME
• February 29, 2024 – Colorado State University, Fort Collins, CO
• March 6, 2024 – Kansas State University, Manhattan, KS
• March 8, 2024* – University of Iowa, Iowa City, IA
• March 22, 2024 –  Appalachian State University, Boone, NC

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).

LECTURE SCHEDULE

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. 

LECTURE SCHEDULE

• October 5, 2023 – University of Delaware, Newark, DE
• October 6, 2023 – Binghamton University, Binghamton, NY
• March 11, 2023 – San Jose State University, San Jose, CA
• March 13, 2023 – San Diego State University, San Diego, CA

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. 

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On the day after Christmas, 2004, the world awoke to an immense tragedy – one of the largest earthquakes ever recorded (M_w 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.

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