Primary Faculty Mentor Name

Paul R Bierman

Project Collaborators

Lee B Corbett

Status

Undergraduate

Student College

College of Arts and Sciences

Program/Major

Geology

Primary Research Category

Engineering & Physical Sciences

Presentation Title

Constraining post-glacial uplift rates in southern Greenland

Time

9:00 AM

Location

Silver Maple Ballroom - Engineering & Physical Sciences

Abstract

Isostatic rebound, Earth’s crust springing back up due to post-glacial melting or other large mass-unloading events drives changes in sea level as the local surface elevation rises. The rate and behavior of this uplift depends on both the physical properties of Earth’s crust and mantle as well as the rate of unloading. Understanding isostatic rebound rates worldwide is therefore necessary to predicting both local and global sea levels, especially in a warming climate with rapidly increasing ice-loss.

This project aims to compare modern uplift rates to past uplift rates at Kulusuk, southeast Greenland to provide a better understanding of isostatic rebound rates and the complex behavior of the crust beneath Kulusuk. GPS data from Kulusuk exhibit extremely rapid uplift rates of 35 ± 5 mm from 2001-2006. These rates have continued to accelerate as ice melt increases. However, these rates may not accurately represent longer timescales; I have used cosmogenic nuclide dating methods to determine the rate of post-glacial uplift since the last glacial maximum (~12kya) for a vertical transect of samples in Kulusuk, sampled within a kilometer of the modern GPS uplift data. These methods involve in-situ­ 10Be extraction of purified quartz and accelerator mass spectrometry analysis (AMS) to determine 10Be/9Be ratios. These ratios are used for calculating exposure ages using MATLAB software and comparing these ages to sample elevation and location data to produce an emergence curve and calculate past uplift rates from ~12kya. 10Be extraction has been completed and samples are currently awaiting AMS analysis, so past uplift data is not yet available. When compared to modern uplift rates, past uplift rates will allow us to accurately estimate emergence in the Kulusuk area for centuries to come if rates are similar and will provide insight into the complex behavior of the Kulusuk crust if rates are different.

This document is currently not available here.

Share

COinS
 

Constraining post-glacial uplift rates in southern Greenland

Isostatic rebound, Earth’s crust springing back up due to post-glacial melting or other large mass-unloading events drives changes in sea level as the local surface elevation rises. The rate and behavior of this uplift depends on both the physical properties of Earth’s crust and mantle as well as the rate of unloading. Understanding isostatic rebound rates worldwide is therefore necessary to predicting both local and global sea levels, especially in a warming climate with rapidly increasing ice-loss.

This project aims to compare modern uplift rates to past uplift rates at Kulusuk, southeast Greenland to provide a better understanding of isostatic rebound rates and the complex behavior of the crust beneath Kulusuk. GPS data from Kulusuk exhibit extremely rapid uplift rates of 35 ± 5 mm from 2001-2006. These rates have continued to accelerate as ice melt increases. However, these rates may not accurately represent longer timescales; I have used cosmogenic nuclide dating methods to determine the rate of post-glacial uplift since the last glacial maximum (~12kya) for a vertical transect of samples in Kulusuk, sampled within a kilometer of the modern GPS uplift data. These methods involve in-situ­ 10Be extraction of purified quartz and accelerator mass spectrometry analysis (AMS) to determine 10Be/9Be ratios. These ratios are used for calculating exposure ages using MATLAB software and comparing these ages to sample elevation and location data to produce an emergence curve and calculate past uplift rates from ~12kya. 10Be extraction has been completed and samples are currently awaiting AMS analysis, so past uplift data is not yet available. When compared to modern uplift rates, past uplift rates will allow us to accurately estimate emergence in the Kulusuk area for centuries to come if rates are similar and will provide insight into the complex behavior of the Kulusuk crust if rates are different.