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HomeMy WebLinkAboutMRC proposal final GULEEDICEtree: Investigating the Climatic Evolution of North American Ice Sheets with TREE Rings 1. Lead organization and Contact Dr. Guleed Ali Department of Geosciences, Stony Brook University guleed.ali@stonybrook.edu (713) 494-4966 255 Earth and Space Science Building, Stony Brook, NY 11794 2. Start and end dates February 1, 2026 – June 1, 2027 3. Deliverables  To MRC: (1) a project report detailing findings, radiocarbon data, digital copies of micro-CT scans, geologic map, and community collaborations; (2) MRC newsletter article; and (3) end of project presentation to the MRC by June 1, 2027.  A proposal to the National Science Foundation (NSF) for follow-up work (see §9h Continuation plan) planned for Fall 2026, subject to the present NSF funding landscape.  A scientific article to be submitted to a high-impact journal by the end of 2027. 4. Project staff  Dr. Guleed Ali, Stony Brook University, has expertise in sedimentology, stratigraphy, geomorphology, geochronology, paleoclimate  Dr. Hung Nguyen, University of Illinois, has expertise in dendrochronology and paleoclimate reconstruction.  Dr. Roger Creel, Texas A&M University, has expertise in Bayesian statistics, glacial isostatic adjustment, and data assimilation  Dr. Marion McKenzie, Colorado School of Mines, has expertise in Pacific Northwest glaciology, glacial geomorphology, Parallel Ice Sheet Model (PISM) configuration, and radiocarbon dating.  Dr. Ryan Venturelli, Colorado School of Mines, has expertise in isotope geochemistry and cutting-edge techniques in radiocarbon analysis. Our team are all early career scientists from diverse backgrounds and expertise with shared common interests in paleoclimate and geology. 5. Partners We will collaborate with Chris Morgan and Barbara Blackie of Peninsula College to develop educational opportunities for students in the region. Both will facilitate connections with potential students. We will partner with Jeff McKibben, Geology teacher for middle school students of Quillayute Valley School District (QVSD), for curriculum development and science outreach. We will partner with Matthew Dubeau of the Olympic National Park to disseminate our data for interpretative work in the Park. 6. Geographic Area Pacific coast of Olympic Peninsula, spanning between La Push and Shi Shi Beach, and Olympic National Park. 7. Permits Olympic National Park permit #OLYM-2025-SCI-0018, active (renewed annually) EFM (permit approved) Campell Global, Tyee Forests Seed Asset, Olympic Timber (permit approved) 8. Project Narrative a) Abstract During the peak of the last Ice Age, ~30,000 to 20,000 years ago, global ice volume reached its maximum. As temperatures warmed, most ice sheets began retreating. However, the Cordilleran Ice Sheet (CIS), which once covered western North America and rivaled the modern Greenland Ice Sheet in size, followed a different path. Instead of retreating, it continued to advance—reaching a maximum as late as 16,100 years ago1,2. The unusually late timing raises an interesting question: what climate forcings or glacial dynamics helped one ice sheet grow while others shrank? We seek to address this question by building a new, high-resolution CIS chronology using ancient trees that the CIS uprooted and buried as it advanced across the Olympic Peninsula. By radiocarbon dating these trees, we will chart the timing of ice advance and retreat across the region. In addition, by measuring annual changes in tree ring width and wood density, we aim to reconstruct—at an unprecedented temporal resolution—paleo-temperature conditions during CIS growth. This project’s findings will (1) fill a major gap in the regional glacial chronology, (2) improve understanding of regional temperature during the last deglaciation, and (3) use the world-class geology of the Olympic Peninsula to build a foundation for sustained educational outreach, bring cutting-edge geoscience into K-12 schools, expand community access to novel science research, and offer research internships and capstone projects to local students. b) Background and context Understanding how Earth’s ice sheets respond to warming presents a core challenge of climate science. Recent projections indicate that the East Antarctic Ice Sheet may gain mass—as shifting weather patterns deliver more snow—even as West Antarctica loses mass3. This projected ice sheet asynchrony has turned attention to past periods when neighboring ice masses responded differently to the same climate forcing. The North American ice sheets present a prime example of ice sheet asynchrony, as sectors of the CIS expanded even as Laurentide deglaciation accelerated4–6. The CIS was uniquely sensitive to air temperature and sea level changes because of its marine-terminating margins and underlying mountainous terrain. Thus, the growth of the CIS provides a valuable analogue for understanding future behavior of modern marine-terminating ice sheets like the GrIS7. However, efforts to reconstruct CIS evolution have been hampered by one missing ingredient: robust and spatially dispersed age control (Figure 1A). This missing ingredient is hiding in plain sight on the Olympia Peninsula, where ancient wood embedded within glacial till now erodes from Pacific coastal bluffs and roadside cuts. Such wood was noted as early as 1973 by Calvin Heusser in his report on regional glacial stratigraphy8. Heusser first hypothesized the wood was overrun as the CIS advanced to its maximum position along the Quillayute River valley. However, the unusually young radiocarbon ages (~16,000 years ago) caused him to propose the wood slumped into (and therefore post-dated) the glacial deposits, prompting the broader community to dismiss the data9. However, recent LiDAR imagery across Washington state offers a new perspective on Heusser’s originally problematic 16,000-year-old wood. Careful geomorphic surveys of the sites show inconsistencies with Heusser’s final interpretation for dead-ice terrain8. Instead, the available LiDAR imagery shows a pristine, glacially fluted surface (Figure 1B), suggesting that the wood was not embedded in a post-depositional environment, but rather included in subglacial sediments as the ice sheet overran the Olympic Peninsula about 16,000 years ago. c) Relevance to MRC funding The research activities of this proposal meet the Coastal MRC funding requirements by satisfying the performance benchmarks of Sound Science and Education and Outreach. The Olympic Peninsula, where the CIS Juan de Fuca lobe reached tidewater, remains a major geographic and temporal data gap in CIS reconstructions. By filling this gap—with new surveys of coastal exposures, radiocarbon ages from ancient trees, and paleo-temperature reconstructions—we will improve the regional glacial chronology and advance understanding of how climate tuning knobs, like temperature and sea level, may impact ice sheet evolution. The data we collect will be published in peer-reviewed journals and made accessible through NOAA’s paleoclimate database (https://www.ncei.noaa.gov/access/paleo- search/). This outcome will directly support the Coastal MRC Program goal of Sound Science. We will translate and disseminate our results for interpretative work of the Olympic National Park, satisfying the Education and Outreach benchmark. This benchmark will also be met by our work to form an outreach and education program with a local K–12 school (QVSD) and community college (Peninsula College). Outreach with QVSD will focus on curriculum development and engagement with students concerning practical matters of science, from funding and peer-review to career paths. Outreach with Peninsula College will include research mentorship through paid/unpaid internships and co-supervised capstone projects. Our goal is to promote understanding of the coastal landscape by advancing knowledge of its recent geologic history and the science used to observe this history. We will evaluate the efficacy of our outreach through pre- and post-event surveys, feedback forms, and reflection activities. Figure 1. Map of the study sites and sampling locations. (A) Olympic Peninsula. Red dot shows location of logs we found in 2024 and dated to ~15,500 yrs BP, indicating a more extensive CIS than the current best estimate4 (orange line). White box marks inset in B. (B) LiDAR of Olympic Peninsula Pacific coast. Arrows show extent of pristine glacial lineations indicative of well-developed warm-based ice flow; ice flows perpendicular to arrow directions. d) Project Objectives Goal 1. Geochronology of the Juan de Fuca lobe, Cordilleran Ice Sheet. Did the CIS truly reach its maximum on the Olympic Peninsula 16,000 years ago? This question cannot yet be answered with confidence because the 14C ages reported by Heusser8 were determined by beta- counting, an outdated technique. Thus, before the region’s glacial history can be revised, new 14C ages are needed using Accelerator Mass Spectrometry (AMS), the current standard. We plan to measure, map, and date glacial deposits across the Olympic Peninsula’s Pacific coastline, from Rialto to Shi Shi Beach, using AMS radiocarbon dating of wood. These data will help establish a definitive glacial chronology for the region. They also will enable future work to estimate earthquake recurrence intervals via offset landforms whose depositional ages were previously unknown. Goal 2. Paleo-temperature Reconstruction via Sub-fossil trees. We propose to reconstruct late-glacial air temperatures from tree rings to determine environmental conditions during the CIS advance across the Olympic Peninsula. These paleo-temperature data will help determine whether the ice sheet expanded in response to summer cooling—consistent with conventional wisdom—or instead during an interval of summer warming, which could have triggered subglacial processes that enhance ice streaming when the glacier bed becomes flooded with meltwater10. We are confident that we can achieve this goal, for two reasons. First, our summer 2024 pilot survey of the northwestern Olympic Peninsula confirmed the abundance of logs of expected age within glacial deposits. Thus far, we have collected and cross-dated three western hemlock logs from lodgment till from near Dickey Lake. Two of these logs are radiocarbon dated to ~15,500 years old. Second, the prospect for collection of additional logs is supported by observations in prior reports8,11,12. Thus, our goal is to collect ~100 ancient logs to build a radiocarbon-anchored chronology to underpin the first continuous, high- resolution air temperature proxy record in the Pacific Northwest. Reconstructing paleotemperatures using ancient tree rings requires analysis of living tree relationships to modern temperatures. Goal 3. Science Outreach. To maximize the impact of our science outreach and strengthen our local partnerships, we aim to support collaborative engagement with two Olympic Peninsula educational institutions. For K–12 engagement, we will partner with Jeff McKibben, a middle school Earth Science teacher at Quillayute Valley School District, to co-develop a curriculum unit aligned with Washington State science standards. This unit will focus on regional examples of glaciation, sea-level change, and climate change, linking global geoscience themes to the local landscape. To further enhance scientific accessibility, we will host virtual classroom sessions introducing students to the scientific process, including how research is designed, funded, and peer reviewed. These discussions will encourage students to explore opportunities in STEM by exposing them to non-profit, federal environmental/national lab, academic, and scientific consulting career paths. For higher education engagement, we will collaborate with faculty partners Barbara Blackie and Chris Morgan of Peninsula College to provide research opportunities for students. We will offer one paid internship and one for academic credit. Both opportunities will include hands-on experience in data collection, interpretation, literature review, and synthesis. Additionally, we will mentor a student in the college’s Honors Program in developing a capstone research project. Through these partnerships, we aim to broaden geoscience participation, generate student curiosity about the Olympic Peninsula’s evolution, and support STEM learning from K-12 to college and beyond. Jeff McKibbon, Barbara Blackie, and Chris Morgan each enthusiastically support our proposed outreach. e) Timeline Our timeline below is organized into academic semesters (not astronomical seasons). Summer 2025 Fieldwork at Olympic National Park to collect preliminary samples of sub-fossil logs using startup funds of team members Fall 2025 Processing the samples collected over the summer (drying, sanding, scanning, ring width measurement) Spring 2026 MRC funding starts (if successful) Radiocarbon dating and micro-CT scanning of Summer 2025 Deliverable to MRC: 14C dating summary and digital copies of micro-CT scans Summer 2026 Complete sample collection on Olympic Peninsula; Develop NSF proposal Deliverable to MRC: (1) shared draft of NSF proposal seeking input on desired involvement/support, (2) field report including written summary, photographs, and locations of study sites and samples Fall 2026 Processing Summer 2026 samples Submit NSF proposal Spring 2027 Radiocarbon dating and micro-CT scanning for Summer 2026 samples Deliverable to MRC: Final summary report that includes all radiocarbon data, digital copies of micro-CT scans, field observations, geologic map, and community collaborations; MRC newsletter article f) Methods The methods presented to accomplish the proposed work include both well-established methodologies and cutting-edge exploratory analyses. Members of our team have laboratory capabilities to ensure a smooth completion of the project within the funding timeline. Goal 1. Geochronology of the Juan de Fuca lobe, Cordilleran Ice Sheet. We will measure sedimentary sections along wave-cut bluffs and stream-cut ravines to reconstruct past depositional environments. Sites will be identified using existing LiDAR data. During section measurement, we will collect wood specimens embedded in the deposits for radiocarbon dating and tree ring measurements. To minimize landscape disturbance, our sampling will involve minimal excavation. We will use a differential GPS to record the elevation and coordinates of each sample and section. Detailed maps of surface deposits will be used to update the regional map of glacial deposits and landforms. In addition, we will document fault scarps and landslides to guide future hazard assessments. Goal 2. Paleo-temperature Reconstruction via Sub-fossil trees. Dendrochronology Sample collection and processing For the modern analogue, cores will be collected from living trees using increment borers (Figure 2). Cross sections of sub- fossil tree logs from lodgment tills (Figure 3a) will be collected with a hand or chain saw, then processed with standard techniques. Increment cores will be glued on wooden mounts. All samples will be dried for 1–2 days, then sanded with incrementally higher grits (Figure 3b). Analysis All samples, modern and ancient, will be scanned at 3200 dpi resolution, imported to the CooRecorder software for ring width measurements. Sub-fossil samples will be identified at species level based on wood anatomy under a microscope. Modern samples will have known dates with the outermost ring being the year of collection (2025 or 2026). Sub-fossil samples will be crossdated to produce a floating chronology. We will then anchor these sub-fossil floating chronologies by radiocarbon dating every alternate ring on the longest-lived tree—dates that will also help improve the IntCal20 calibration curve13. As western hemlocks can live for several centuries, we expect about 100 radiocarbon dates—a number made possible by the in-house graphite conversion capabilities at the Venturelli lab, which will reduce the per-sample cost three-fold to ~$80/sample. Finally, density and anatomical features of the wood samples will be measured at ~1 µm resolution in the University of Illinois’ X5000 micro-CT system to give further environmental context for the seasonal timing of wood growth (Figure 3c). Figure 2. Collecting tree cores with an increment borer. Figure 3. Log collection and processing. a) a cross section of a glacially deposited log still in place, b) close-up of the annual rings after being sanded at 1000-grit, c) cell structure under a micro-CT scan. Temperature Reconstruction Once the tree ring chronologies are anchored in time by the radiocarbon analysis, we will use standard dendrochronological methods14,15 to reconstruct Pacific Northwest summer temperatures ~16,000–15,000 years ago. To do so, we will first establish the relationship between tree growth, density, and temperatures by regressing ring width and density of living trees in Olympic National Park on annual average summer temperature across the Peninsula. Ring width and density data from the glacially deposited wood samples will then be inputted into the regression to reconstruct ancient temperatures. Goal 3. Science Outreach. We will use Zoom software to remotely connect with students from QVSD and Peninsula College. Outreach activities with QVSD and Peninsula College will not require additional equipment or supplies. Research experiences with students at Peninsula College will focus on building computational fluency using existing datasets including tree ring data developed from this work, stream gauge, temperature, and/or sea level records. g) Extent and impacts Our sampling sites for Goal 1 will cover about 60–75 km2 along the Pacific coast, primarily within the Olympic National Park. While the study area is mostly on protected land, the findings will positively impact coastal communities by improving understanding of local geology, landscape evolution, and potential geologic hazards including landslides and earthquakes. For Goal 2, our sampling sites span ~150 km2 in the northern Olympic National Park. We anticipate that this work will positively impact the broader Olympic Peninsula communities, for it offers important insights into how contemporary forests are responding to climate change, and how these changes can be contextualized in geologic timescales. The modern tree ring data we produce for our data comparison will also be impactful when used for forest management and projections of future ecological shifts. h) Continuation plan The results from this project will serve as the foundation for a larger proposal to the National Science Foundation’s Life and Environment Through Time program. If successful in acquiring NSF funding, we will return to the area to expand sampling efforts across the Olympic Peninsula and expand the scope of our work to the development of a full ice sheet reconstruction using the expertise of our team. A full ice sheet reconstruction using the high-resolution temperature data produced from this MRC-funded work will be the first of its kind at these proposed temporal and spatial scales. 9. Project Budget Category Detail MRC Request Total Salaries and Benefits or hourly wages Internship salary for student at Peninsula College (Goal 3) $2880 $2,880 Supplies/Equipment Chainsaw rental (Goal 2) Lab supplies for graphitization (Goal 2) $440 ($220/week) $1500 $1,940 Travel Travel and accommodation for 4 IceTree team members (Goals 1–3) Travel for Peninsula College student (Goal 3) See itemized Travel Details below $7,006 Contracted services Radiocarbon dating (Goal 2) $80 / sample for 100 samples $8,000 Indirect expenses (All such expenses should be itemized.) Other Shipping (Goals 1–2) $500 $500 Totals $20,326 Travel Details Personnel Itinerary Estimated cost Guleed Ali Roundtrip ticket EWR <--> SEA $300 Hung Nguyen Roundtrip ticket CMI <--> SEA $350 Roger Creel Roundtrip ticket CLL <--> SEA $350 Marion McKenzie Roundtrip ticket DEN <--> SEA $150 Expense Total cost PI car rental ($130/day for 12 days + taxes and fees) $2500 Fuel cost ($4.50 / gallon * 1 gallon / 25 miles * 1000 miles) $216 Student transportation (roundtrip Peninsula college to Forks: $0.70 / mile * 200 miles) $140 ~Half per diem rate ($50/day/person for 12 days) $3000 APPENDICES References 1. Porter, S. C. & Swanson, T. W. Radiocarbon Age Constraints on Rates of Advance and Retreat of the Puget Lobe of the Cordilleran Ice Sheet during the Last Glaciation. Quat. Res. 50, 205–213 (1998). 2. Haugerud*, R. A. Deglaciation of the Puget Lowland, Washington. in Untangling the Quaternary Period—A Legacy of Stephen C. Porter (eds. Waitt, R. B., Thackray, G. D. & Gillespie, A. R.) vol. 548 0 (Geological Society of America, 2021). 3. Seroussi, H. et al. ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century. The Cryosphere 14, 3033–3070 (2020). 4. Dalton, A. S. et al. Deglaciation of the north American ice sheet complex in calendar years based on a comprehensive database of chronological data: NADI-1. Quat. Sci. Rev. 321, 108345 (2023). 5. Darvill, C. M., Menounos, B., Goehring, B. M., Lian, O. B. & Caffee, M. W. Retreat of the Western Cordilleran Ice Sheet Margin During the Last Deglaciation. Geophys. Res. Lett. 45, 9710–9720 (2018). 6. Darvill, C. M., Menounos, B., Goehring, B. M. & Lesnek, A. J. Cordilleran Ice Sheet Stability During the Last Deglaciation. Geophys. Res. Lett. 49, e2021GL097191 (2022). 7. Menounos, B. et al. Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene Termination. Science 358, 781–784 (2017). 8. Heusser, C. J. Environmental sequence following the Fraser advance of the Juan de Fuca lobe, Washington. Quat. Res. 3, 284–306 (1973). 9. Post, A. & Streveler, G. The Tilted forest: Glaciological-Geologic implications of Vegetated neoglacial ice at Lituya Bay, Alaska. Quat. Res. 6, 111–117 (1976). 10. Simkins, L. M., Greenwood, S. L., Winsborrow, M. C. M., Bjarnadóttir, L. R. & Lepp, A. P. Advances in understanding subglacial meltwater drainage from past ice sheets. Ann. Glaciol. 63, 83–87 (2022). 11. Wyshnytzky, C. E., Rittenour, T. M., Nelson, M. S. & Thackray, G. Luminescence dating of late Pleistocene proximal glacial sediments in the Olympic Mountains, Washington. Quat. Int. 362, 116–123 (2015). 12. Wyshnytzky, C. E., Rittenour, T. M., Thackray, G. D. & Shulmeister, J. Stratigraphic and geomorphologic evidence of three MIS 2 glacial advances in the South Fork Hoh River valley, Olympic Mountains, Washington, USA. Quat. Res. 92, 708–724 (2019). 13. Reimer, P. J. et al. The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP). Radiocarbon 62, 725–757 (2020). 14. Nguyen, H. T. T., Turner, S. W. D., Buckley, B. M. & Galelli, S. Coherent Streamflow Variability in Monsoon Asia Over the Past Eight Centuries—Links to Oceanic Drivers. Water Resour. Res. 56, (2020). 15. Cook, E. R. et al. Asian Monsoon Failure and Megadrought During the Last Millennium. Science 328, 486–489 (2010).