Rates of Change on Spillway Lake Ngozumpa Glacier, Nepal Ulyana N. Horodyskyj University of Colorado Boulder July 14, 2013
Trail Map
• Background • The beginning: 2011 time-lapse of supraglacial ponds
• 2012/13 supraglacial ponds + Spillway Lake changes
• Sherpa-Scientist Initiative • Pilot project in Cordillera Blanca
Melting glaciers
Supraglacial lake formation
rising temperatures
central and eastern Himalaya greatly affected
due to lower angle (slopes) of glaciers
Loss of life and infrastructure
Increase in flood potential
Enhanced melting
Warming climate
1985 - Dig Tsho outburst ($1.5 million damages)
due to storage of water in lakes
due to exposure of bare ice walls
David Breashears, GlacierWorks
Snapshots of Change N
N N
Khumbu
Imja Ngozumpa
Ngozumpa Glacier, Nepal
BBC
Side View Ngozumpa Glacier Cho Oyu
18 km
BBC
1951
2009 - Breashears
Project Objectives 1. Use time-lapse photography from melt seasons to qualitatively and semi-quantitatively document lake changes. 2. Document terminal (spillway) lake area and depth changes, to determine growth rates through time. 3. Quantify some physics of lake deepening and expansion.
Back in 2011...
Time-Lapse Locations
2010 Dcam
Ucam
300 m
2012 Dcam Lake X
Ucam
300 m
November 2012: Investigating a Spillway Situation
#1 #2
#3
N
#1
#2
Everest Base Camp 2008 Spy Accusations
#3
N
Important Findings: - Multiple drain/fill events occur throughout a melt season. - Satellites may mask this volume loss.
- Drainages can occur even post-freeze. - End of melt season may not mean end of volume loss.
Spillway Lake: Past and Present
Area Changes: 2001-2010
Thompson et al., 2012
Area Changes: 2010-2012
in progress
2010
2012
x
x
x
x
x
x
N
Depth 2010
Thompson et al., 2012
Depth 2012
in progress
Difference Map
in progress
Inflow
Inflow NW NE
Thermal Characteristics
MAIN
SW
Surface Temperatures
SW Stable Basin
Bottom Temperatures
Inflow influence?
Subaqueous calving?
Surprise Finding: Arsenic Low (< 9 ppb) Moderate (10-15 ppb) High (16-30 ppb) Very High (> 30 ppb)
November 2012 Training
May 2013 November 2012 Training
Cordillera Blanca
â&#x20AC;˘â&#x20AC;Ż Supraglacial pond comparisons, through the AAC Climber Science Program
Water Chemistry Morphological Changes
Back-wasting and Down-wasting Rates
blackicehimalaya.wordpress.com www.glacierworks.org