Tracking Ice Flow in Two Greenland Outlet GlaciersTracking Ice Flow in Two Greenland Outlet Glaciers
Michael Jefferson Jr.Elizabeth City State UniversityResearch & Discover Summer 2010
Mentor: Mark Fahnestock
Michael Jefferson Jr.Elizabeth City State UniversityResearch & Discover Summer 2010
Mentor: Mark Fahnestock
ObjectivesObjectives
• To identify the best pairs of files to investigate ice flow– There has to be a pair of images in order to see a change in the data
• Create a new program to process the images
• Gather the images and process them with the appropriate parameters
• Compare findings from each of the processed image pairs
• To identify the best pairs of files to investigate ice flow– There has to be a pair of images in order to see a change in the data
• Create a new program to process the images
• Gather the images and process them with the appropriate parameters
• Compare findings from each of the processed image pairs
Glaciers and Remote SensingGlaciers and Remote Sensing
• The Landsat 7 satellite orbits the earth and takes pictures of earth’s features
• The data collected by this satellite was used in my research
• The Landsat 7 satellite orbits the earth and takes pictures of earth’s features
• The data collected by this satellite was used in my research
LocationLocation
•Latitude(62.4), Longitude(-49.6)Kangiata Nunata Sermia(KNS)
LocationLocation
Nunatakavsaup Sermia(NKS)
• Latitude(74.6) ,Longitude( -56.0)
•The distance was 1300 km between the two glaciers
NKS
Selecting Image filesSelecting Image files
• Files where downloaded from the United States Geological Survey (USGS) GLObal VISsualization Viewer (GLOVIS) website
• There were many images with too much cloud cover– If clouds cover features then the changes can not be tracked
• 2004, 2005, 2007 used for KNS
• 2001, 2002, 2005, 2010 used for NKS
• Files where downloaded from the United States Geological Survey (USGS) GLObal VISsualization Viewer (GLOVIS) website
• There were many images with too much cloud cover– If clouds cover features then the changes can not be tracked
• 2004, 2005, 2007 used for KNS
• 2001, 2002, 2005, 2010 used for NKS
The ProgramThe Program
• To track features a program was used – The idea of tracking glaciers through pairs of images was developed 20 years ago• Dr. Bob Bindschalder and Dr. Ted Scambos
• Dr. Mark Fahnestock wrote the program– Restrictions: Only output the changes for one iteration over a single image
• To track features a program was used – The idea of tracking glaciers through pairs of images was developed 20 years ago• Dr. Bob Bindschalder and Dr. Ted Scambos
• Dr. Mark Fahnestock wrote the program– Restrictions: Only output the changes for one iteration over a single image
The Program(Cont’d)The Program(Cont’d)
• The program works by reading a line from a .txt file– A text file includes the two images and the geographic locations where the moving should be present
• The program works by reading a line from a .txt file– A text file includes the two images and the geographic locations where the moving should be present
The Program cont’d The Program cont’d
srcimgdel: 10 destimgdel: 25
Source 20x20Destination 50x50
Program IterationProgram Iteration
• Example of a single point of an iteration
• Describes the correlation over the source and destination
• The closer to the color red means the more “good” unique points
• Example of a single point of an iteration
• Describes the correlation over the source and destination
• The closer to the color red means the more “good” unique points
Creating a New ProgramCreating a New Program
• The previous program only ran one set of iterations per image
• Not all sections of the image had distinct features
• Not all images were 100% cloud free
• A new program was created to display more than one
iteration on a single image
• The previous program only ran one set of iterations per image
• Not all sections of the image had distinct features
• Not all images were 100% cloud free
• A new program was created to display more than one
iteration on a single image
Pic of one iteration
New Program: Multi-Velocity
New Program: Multi-Velocity
• Display multiple iterations with different parameters
• Display the average velocity of the “good points”
• Good points were the iteration points that had a unique correlation surface values over a specified amount
• Display multiple iterations with different parameters
• Display the average velocity of the “good points”
• Good points were the iteration points that had a unique correlation surface values over a specified amount
Output from New Program
Output from New Program
Green Plus- Best Correlation
Red Hexagon - Worst Correlation
Mapping ChangesMapping Changes
Results for NKSResults for NKS
This line represents the beginning of the comparable data
2003-20052003-2005
•In years there was a large Ice front retreat this is what drove the large change in velocity over the years
•Figure by: Ryan Cassotto
20052006200720082009
20002001200220032004
Results for KNSResults for KNS
Around 1 to 1.5 Km from the ice front my data was approximately the same through the years
ConclusionConclusion
• There was a large change in velocity in the northern glacier NKS during the years of 2002-2005
• There was no apparent changes in the southernmost glacier KNS
• There was a large change in velocity in the northern glacier NKS during the years of 2002-2005
• There was no apparent changes in the southernmost glacier KNS
Future WorkFuture Work
• Research more glaciers to investigate more velocity changes using satellite data
• Change the program to be more efficient to run on larger collections of data
• Research more glaciers to investigate more velocity changes using satellite data
• Change the program to be more efficient to run on larger collections of data
AcknowledgementsAcknowledgements
• Dr. George Hurtt(Research & Discover)
• Dr. Mark Fahnestock (UNH Researcher)
• USGS GLOVIS (Image Database)• Ryan Cassotto(Graduate Student)• Stephen Hale(UNH Professor)
• Dr. George Hurtt(Research & Discover)
• Dr. Mark Fahnestock (UNH Researcher)
• USGS GLOVIS (Image Database)• Ryan Cassotto(Graduate Student)• Stephen Hale(UNH Professor)
Questions/CommentsQuestions/Comments
