Jakobshavn Isbrae Glacial Retreat Darin Erickson Aaron Gaither

Project Goals Time lapse imagery showing glacial transformation Area change Retreat distance Link glacial retreat with increasing temperatures Correlate temperature with glacial retreat Provide information for future analysis Comparison to other glacial studies

Jakobshavn Glacier Location Characteristics Area Studied West Greenland Near the city of Ilulissat Coordinates: 69.1667° N, 49.8333° W Characteristics Drains 6.5% of Greenland’s ice sheet Produces 10% of Greenland's icebergs One of the worlds fastest moving glaciers Area Studied Main Glacier Northern Outlet Image http://icestories.exploratorium.edu/dispatches/transportation-in-support-of-science-the-twin-otter/ Information http://en.wikipedia.org/wiki/Jakobshavn_Glacier

Data/Acquisition 5 Landsat Images from Landsat 4,5, 7 and 8 1985-2014 Less than 20% cloud cover Acquisition from: USGS Earth Explorer Path 9 – Row 11 Temperature data from ILULISSAT (Neighboring town to Jakobshavn glacier) Image ID Landsat # Image Acquisition # of Bands LT50090111985184KIS00 Landsat 4-5 TM July 3rd, 1985 7 LT50090111990166KIS00 June 15th, 1990 LE70090112001188EDC00 Landsat 7 SLC-on July 7th, 2001 9 LE70090112009210EDC00 Landsat 7 SLC - off July 29th, 2009 LC80090112014184LGN00 Landsat 8 OLI July 3rd, 2014 12

Software Used Erdas Imagine ArcGIS 10.2 Google Earth http://www.walis.wa.gov.au/isde7/assets/erdas_logo_no_tagline_large.jpg/view http://www.processamentodigital.com.br/wp-content/uploads/2011/10/arcgis10b.png http://wildsouth.org/wp-content/uploads/2012/11/logo-Google-earth.jpg

Preprocessing Layer Stack Set Spectral Bands for 1985-2009 Images (Landsat 7) Red 4 Green 3 Blue 2 Set Spectral Bands for 2014 Images (Landsat 8) Red 5 Green 4 Blue 3 Subset No Rectification needed due to use of Landsat images Layer Stacking- We then selected each individual Tiff file to be stacked in ascending order. After completing these steps for each of the five images, we were able to clearly view our area of interest. All Images had to undergo these steps No Rectification needed due to use of Landsat images because they were all from the same path 9 and row 11

Subset Images Cut down our study area size

Processing/Classification Initially used unsupervised classification 7 classes, 50 max iterations, .98 convergence threshold to identify cover types Snow Open Water Cloud Cover Fjord Ice Glacier Vegetative cover Non-Vegetative Cover Classification Failure Why we tried unsupervised- It was a quick and easy algorithm to see if we could identify all cover types accurately Failed because it did not successfully identify the cover types to the precision that we wanted. So we tried supervised

Processing/Classification Supervised Classification 7 classes Snow Open Water Cloud Cover * Fjord Ice Glacier Vegetative cover Non-Vegetative Cover Created 10 polygons within each cover type (To identify our training data) Classification Success Cloud cover was only classified in one image so we didn’t feel it was necessary to do a radiometric rectification of this image to eliminate the cloud cover because it did not cover our study area and was not significant. NON Parametric decision rule Considers range of DN values Two dimensional polygon is drawn around training pixels Advantages- Fast, simple consider variance Picture on next slide

Supervised Classification Snow was not classified because the DN values were so similar to the Fjord so they were just classifies as fjord.

Accuracy Assessment Search Count 1024 50 point of stratified random distribution 2014 Accuracy Assessment By choosing stratified random, we were able to have an equal distribution of points across the image while still maintaining randomization within each classified pixel value Aarons Slide

Basic Digitizing Digitized glacial edge across entire study area Shape files overlaid on 2014 subset image Distance measurements Area Measurements We computed values of change relative to 1985 and change relative to the previous study year. Picture on next slide

Darin Ends HERE

Measurement Relative to Previous Study Year Main Glacier North Outlet Year Retreat Distance (km) Change in Area (km2) 1985 -1990 -1.15 -7.88 -0.745 -1.64 1990 -2001 2.57 22.98 0.957 2.11 2001- 2009 12.52 144.35 2.05 6.19 2009-2014 2.27 31.6 0.453 2.29 Explain the Negative for glacial advance Explain the positive for glacial retreat We noticed a significant retreat distance and change in area in years 2001 – 2009. We calculated 75% of the total glacial retreat occurred between the years of 2001 – 2009. 75% of the total glacial retreat occurred between the years of 2001 – 2009

Measurements Relative To 1985 Main Glacier North Outlet Year since 1985 Retreat Distance since 1985 (km) Area lost since 1985 (km2) Distance since 1985 (km ) Area since 1985 (km2) 5 -1.15 -7.88 -0.75 -1.64 16 1.42 15.1 0.20 0.47 24 13.94 159.45 2.25 6.66 29 16.20 191.05 2.70 8.95 Total Average retreat distance of 0.56km/yr Total retreat distance 16.2 km Area lost 6.6km2/yr Total of 8.95 km2

This helps to visualize the 75% of the total glacial retreat occurred between the years of 2001 – 2009

Temperature Comparison We noticed a slight increase in average yearly temperature from 1985 – 2013. While an increase of only 1-2 deg. Celsius may not appear to be significant, it warrants a correlation between glacial retreat and rising temperature. We also noticed a substantial increase in temperature of 9.1 deg. Celsius between the years 2003 – 2008. This is also the time frame of the major glacial retreat.

Discussion Points Glacial advance between 1985-1990 Glacial retreat 1990-2014 Major glacial retreat during 2001-2009 Correlated with increase in temperature Several factors we didn’t acquire data for Several factors we didn’t acquire data for -sea temperatures -precipitation amounts -sediment flux and erosion -previous data before 1985

Further Study Data collection of surrounding Labrador Sea temperature Change detection of vegetation and exposed land area Comparison to similar glaciers Fjord ice and open water distribution Further understanding of historical measurements prior to 1985 With more research and data collection of the area, we might be able to present a stronger correlation between temperature and glacial retreat.

Questions