Unit Affiliation: Geochemistry, Lamont-Doherty Earth Observatory (LDEO)
Unit Affiliation: Marine and Polar Geophysics, Lamont-Doherty Earth Observatory (LDEO)
The GRate project is funded by the National Science Foundation and led by Jason Briner @ University at Buffalo in collaboration with a team of science experts from multiple disciplines and academic institutions. The project grew from the earlier "Snow on Ice" initiative that focused on the fluctuations of the Greenland ice sheet throughout the holocene, focusing on SW Greenland. GRate will expand that work, further exploring Greenland's ice sheet stability through the linked systems of ocean, ice and atmospheric conditions using paleoclimate proxies and infusing these into an updated Greenland wide ice sheet model.
This page provides a summary of the project. The complete information is available on the GRate project website.
Reconstructing Greenland’s Ice Margin is done through radiocarbon dating sediment samples cored from pro-glacial lakes (lakes created along the ice sheet margin from glacial meltwater) to track ice sheet retreat and expansion. Quartz rock samples are collected for cosmogenic nuclide analysis from both free standing glacial erratics and rows of rocky moraines deposited along the ice sheet margin. Paired analysis of a suite of different isotopes (14C, 10Be, 26Al and 36Cl) are used to reconstruct the history of the ice sheet margin over the past 20,000 years. Both sediment and rock samples are used to constrain Greenland’s minimal Holocene ice edge. (Jason P. Briner, U@B, PI, Nicolás Young, LDEO, PI, Joerg Schaefer, LDEO, PI)
Image: Quartz sample are collected from a glacial erratic deposited on the landscape as the ice sheet retreated for paired radioactive isotope analysis. The surface exposure dating is correlated with the ages from the lake sediment cores, applying a second independent method of dating Greenland’s ice sheet extent.
Hydroclimate data is calculated from hydrogen isotopes extracted from the water in lake sediment cores and leaf waxes from local plant cover using stable hydrocarbon chains. Precipitation isotopes reflect moisture sources, with lake water isotopes reflecting seasonality through their inflow and evaporation. Thousands of years after the leaf waxes are blown into the lake their hydrocarbon chains remain unchanged and can be used as a proxy for paleoclimate.(Elizabeth Thomas, U@B, PI)
Image: Samples prepared and ready to be run through the isotope ratio mass spectrometer to establish a hydrogen isotope ratio. In the lab solvent is pumped through the mud to release the waxes, the sample is then purified and analyzed for the hydrogen isotopes of the leaf waxes. These are used to reconstruction a picture of paleo-climate temperature and moisture balance in the Holocene. (photo D.Levere University at Buffalo)
Arctic dinocysts assemblages are analyzed as a proxy for sea ice cover along Greenland's coast. Dinocysts are dormant zygotes of dinoflagellates, small plankton, that in the Arctic can be used as paleoclimate markers of past sea ice cover, water temperature and salinity. Through collecting ocean sediment cores in targeted areas along the Greenland coast the dynocyst assemblages can provide temperature and ice data for the area. (Anne de Vernal, GEOTOP Montreal, PI)
Greenland Ice Core and Pollen Data extended through the Holocene is used to reconstruct the surface temperature and ice accumulation. Large proxy data assemblages have been used to provide to provide boundary conditions tol guide the ice sheet modelers. (Greg Hakim, U Washington, PI, Eric Steig, U Washington, PI)
Modeling efforts will continue to integrate observational ice surface data and improved Greenland bed topography data into both expanded regional models and the Greenland-wide Ice Sheet System Model (ISSM) to continue to move this powerful model into more recent Geologic history. The models developed in our prior ARCSS project, Snow on Ice, focused on the SW geographic region of Greenland over the last 8000 years in the Holocene. The GRate project will expand the modeling to look at change across the broader Greenland Ice Sheet over this same period. (Jesse Johnson, Montana, PI, Mathieu Morlighem, Dartmouth, PI, Eric Larour, JPL, PI, Josh Cuzzone, JPL, PI)
Education & Outreach efforts are focused on building diverse pathways into the Geosciences. We created a set of science trading cards that focused on our Early Career Scientists and bringing them to life as 'superheroes' with cool tools that enabled the super powers they use to uncover new scientific insights. Created by scientist and artist Jeremy Stock, these incredible superheroes together focus on ‘system science’ as they uncover new findings about past climate, that when matched to the present help us build models about the future. Educators will find out NGSS aligned instructional materials that address the question ‘How do we know about the past?’ as they explore the use of ‘science proxies’. Each superhero scientist has a set of activities and supports that help you bring their science story to life in the classroom in an engaging and personal way!
Image: An example of Science Superhero cards of some of our amazing scientists. Full sets of Middle School and High School curriculum that explore "How do we know about the past?" can be downloaded. The full project website is here.
The sustainability of the Ganges-Brahmaputra Delta and Bangladesh depends on the balance of sea level rise, land subsidence and sedimentation. We are measuring the latter two across the coastal zone.
Two M.P.A. in Environmental Science and Policy Program traveled to Thailand to share their ideas in the 2023 Youth Voice Dialogue.
The long-term importance of energy efficiency is clear, but short-term competing interests can make it difficult to pursue energy efficiency and decarbonization goals.
Emergency managers are already facing the consequences of climate change in the workplace. How can education programs better prepare them for crises?
Decades after the last grizzly bear was seen in Washington State’s North Cascades, efforts to bring them back have been met with both enthusiasm and resistance.
EVs will replace gas-powered vehicles when they are less expensive, more feature-packed and more reliable than cars with internal combustion engines.
A Q&A with Rose Oelkers, a Ph.D. candidate at the Lamont-Doherty Earth Observatory who studies tropical trees and their response to changes in the environment.
A Q&A with IRI’s Amanda Grossi, who works with farmers in Africa to help manage climate risk.
Marco Tedesco explains how remote-sensing data can reveal how Greenland's ice sheets are melting.
A Q&A with Thalia Balkaran, postdoctoral research scientist at the Columbia Climate School’s National Center for Disaster Preparedness, in honor of the International Day of Women and Girls in Science.
The Impact of the Stratosphere on Arctic Climate