Motivation Behind My Research

 

     The surface of our planet is known to be warming for both natural and anthropogenic (human related) reasons. The human influence on global warming was first proposed in 1954 when it was shown that atmospheric levels of CO2 were increasing. It has subsequently been recognized by the Intergovernmental Panel on Climate Change (IPCC - 1995 & 2001) that humans are changing our atmosphere sufficiently enough to cause it to trap more and more heat from the sun.  This process is known as the "Greenhouse Effect".  Humans activities that are contributing to the greenhouse effect include, but are not limited to, the burning of fossil fuels, methane production, and deforestation. These human activities are not only causing temperatures to increase, but they are also polluting the atmosphere and causing sea level to rise.  Unfortunately, it seems that the human influence on global temperatures will increase as global populations grow and more countries become industrialized.  Today, scientists from many disciplines including climatology, meteorology, geology, glaciology, remote sensing, and biology are working together to determine how our oceans,  ice sheets, plants, and animals are responding to increasing temperatures on Earth. My contributions to this problem are broken down below, but in general, I am an Earth scientist specializing in glaciology who travels to Antarctica and Greenland to look for signs of climate change.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Research conducted through the Climate Change Institute, Department of Earth Sciences, University of Maine, Orono, ME

 

Mass Balance of the West Antarctic Ice Sheet

US-ITASE is the United States component of the International Trans Antarctic Scientific Expedition (article). Researchers involved in ITASE drive across portions of Antarctica collecting geophysical data and ice cores. Four traverses have already been completed (map). The major goal of ITASE is to determine how climate on Earth has changed over the past 200 years. We know that warming has occurred, but it is unclear how the whole earth system is responding and what this will mean for the future. By combining  measurements of ice flow with radar and ice core data we are compiling the most complete ground-based dataset of mass balance available for West Antarctica. Gordon Hamilton presented our most recent results from this research at the IGS conference in Italy (August 25-29; abstract; link).

 

ICESat/GLAS Calibration

Using ground-based measurements in West Antarctica, we have established control points for NASA's Geoscience Laser Altimetry System (GLAS) on the ICESat satellite that was successfully launched on January 12, 2003 (Spikes and Hamilton, 2003). GLAS is designed to measure changes in elevation over most of Antarctica and Greenland. GLAS measurements are expected to answer the question, "How are Earth's ice sheets responding to global warming?" However, to determine the validity of space-based measurements, results must be compared to reliable measurements made on the surface of the ice sheet. I will be speaking on this topic at the ISRSE conference in Honolulu, Hawai'i (Nov 10-14, 2003). This project is funded by NASA's Earth System Science Fellowship program (NGT5-30426) (article).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Research conducted through the Byrd Polar Research Center, Department of Geological Sciences, The Ohio State University, Columbus, OH

Mass Balance of West Antarctic Ice Streams

      In an effort to determine how the West Antarctic Ice Sheet is responding to rising temperatures, we used airborne laser altimetry to measure elevation changes over time. The method involves the advanced technologies of GPS (global positioning system), GPR (ground penetrating radar), INS (inertial navigation system), and laser ranging (Spikes et al., 2003a). We concentrated on the Ross Ice Stream region in West Antarctica, because these features are the major conduits that drain this portion of the ice sheet. Repeat surveys of these regions enabled us to track how surface elevations changed over a two-year period. The surveyed portion of Kamb Ice Stream (ISC) is thickening at an average rate of 0.12 m a-1 and the surveyed portions of two Whillans Ice Stream tributaries are shown to be thinning at average rates of 0.57 m a-1 (Whillans-1) and 0.64 m a-1 (Whillans-2) (Spikes et al., 2003b). The net mass balance for the three surveyed areas (total of 14,542 km-2) is negative and may indicate that the entire Ross Ice Stream region is losing mass and contributing to current rates of sea level rise. However, the amount of ice lost may be balanced by snow accumulation in other regions. This research funded by the National Science Foundation through a grant  to Dr Ian Whillans (OPP-9615114). 

 

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Blue Ice and Meteorites

Exposures of meteorite bearing blue ice surfaces near the margin of the East Antarctic Ice Sheet (EAIS) raise central questions concerning the climatic and glaciological conditions that must exist in order for these features to form and persist. Planetary scientists and geologists have long been interested in these blue ice zones because of the thousands of meteorites that have been found lying on their surfaces. Most of the work done in these zones has been to collect and age date the meteorites and to describe the processes that concentrate them on the ice surface. As glaciologists we are interested in the stability of these features and what they indicate about the recent history of the EAIS. Understanding the current mechanics of blue ice areas could answer many important questions about the past and future of the EAIS.  Our work at the Allan Hills combines the knowledge gained from decades of previous research with new measurements of ice flow and mass balance. Repeat precision GPS measurements of markers in ice were used to calculate ice flow velocity vectors of the ice near the Allan Hills in East Antarctica. One objective is to test if the concentration of meteorites and their terrestrial ages can be explained with current ice sheet behavior, and if not, what past behavior could account for the distribution of meteorites. Another objective is to determine how this part of the ice sheet is responding to global warming. We will visit the Allan Hills for a third time in January 2004. This research was originally funded by the National Science Foundation through a grant awarded to Dr. Ian Whillans (OPP-xxxx). We are continuing this work through a new NSF grant awarded to Dr. Gordon Hamilton (OPP-xxxx).