The Quelccaya Ice Cap in Peru has undergone a remarkable reduction in size, dwindling from 58 square kilometers to 40 square kilometers between the years 1988 and 2023, primarily as a consequence of climate change. This diminishing expanse has not only led to the loss of invaluable historical climate records preserved within the ice but has also triggered significant environmental alterations, including the emergence of meltwater lakes and glacial floods.
Safeguarding the history of this vanishing ice cap in the Peruvian Andes relies on the meticulous analysis of ice cores and satellite imagery. Perched upon a lofty plateau within the Andes Mountains of Peru, the Quelccaya Ice Cap, like its counterparts across tropical regions globally, finds itself vulnerable to the relentless impacts of climate change, despite the comparatively frigid altitudes it occupies.
A striking satellite image, captured on September 3, 1988, by the Thematic Mapper on Landsat 5, reveals the initial extent of the Quelccaya Ice Cap. Fast forward to October 22, 2023, and a subsequent image, obtained through the Operational Land Imager on Landsat 8, depicts the ice’s remarkable retreat. Christopher Shuman, a glaciologist affiliated with the University of Maryland, Baltimore County, based at NASA’s Goddard Space Flight Center, approximates that in 1988, the ice covered an expanse of about 58 square kilometers (22 square miles), while by 2023, it had dwindled to just over 40 square kilometers (15 square miles).
Notably, the later image reveals the emergence of meltwater lakes, particularly along the western periphery of the ice cap. Many of these lake basins, sculpted by the movement of ice, have severed ties with the ice that initially gave rise to them. Additionally, the ice cap serves as a vital source of water for the Vilcanota River and Lake Sibinacocha, located to the west of the imagery, historically catering to the needs of nearby and downstream communities.
The stark transformation is further underscored by the appearance and disappearance of several lakes during the intervening years, including one incident in November 2022, when a glacial lake outburst flood (GLOF) occurred. Shuman detected this event in Landsat images, showcasing the draining of a lake on the ice cap’s eastern flank and the extensive path left by the swift floodwaters, which scoured the vegetation. The scar from this flood remains visible in the 2023 image.
Even before the advent of Landsat satellites, scientists were aware of the ice cap’s diminishing stature. Since 1974, Lonnie Thompson and a team from Ohio State University have undertaken expeditions to closely examine Quelccaya.
“Both ground-based observations and satellite imagery enable the documentation of glacier retreat rates, which currently average approximately 14 meters per year,” Thompson remarked. The team led by Thompson has shared Landsat images, chronicling the ice cap’s retreat, with local authorities and indigenous populations residing in proximity to the ice cap.
As tropical glaciers on our planet face extinction, so too are the temperature and climate records, which have been diligently preserved within their icy cores. Thompson’s team has extracted ice cores from numerous tropical glaciers, including Quelccaya. By scrutinizing the layers within these cores, scientists can access a nearly annual chronicle of air temperatures and atmospheric composition spanning back 1,800 years.
“Tropical glaciers may present our sole opportunity to capture long-term changes in global mean temperatures, as well as the transformations in climate and the environment within an area that encompasses 50 percent of Earth’s surface and houses over 50 percent of our global population,” Thompson emphasized.
Regrettably, at Quelccaya, this invaluable record may vanish by the close of the 21st century—an anticipated timeframe for the ice cap’s ultimate demise. As Thompson poignantly noted, “The only testament to its existence will be the terrestrial and satellite images portraying what once was a magnificent ice cap positioned directly above the Amazon Basin.”
Images courtesy of NASA Earth Observatory, by Wanmei Liang, utilizing Landsat data from the U.S. Geological Survey.
Frequently Asked Questions (FAQs) about Quelccaya Ice Cap Retreat
Q: Why is the Quelccaya Ice Cap in Peru shrinking?
A: The Quelccaya Ice Cap in Peru is experiencing a significant reduction in size primarily due to the effects of climate change. Rising temperatures are causing the ice to melt at an accelerated rate.
Q: What are the consequences of the ice cap’s retreat?
A: The retreat of the Quelccaya Ice Cap has several consequences, including the loss of historical climate data preserved in the ice. It also leads to the formation of meltwater lakes and the risk of glacial floods, impacting both the environment and nearby communities.
Q: How is the retreat of the ice cap being monitored?
A: The retreat of the Quelccaya Ice Cap is monitored using satellite imagery, specifically Landsat data. Scientists and researchers also conduct ground-based observations to document the rate of glacier retreat.
Q: What is the significance of the historical climate data preserved in the ice?
A: The ice cores from the Quelccaya Ice Cap contain a valuable record of air temperatures and atmospheric composition dating back 1,800 years. This data is essential for understanding past climate variations and can provide insights into global climate trends.
Q: Is there any hope of preserving the ice cap?
A: Unfortunately, the Quelccaya Ice Cap is expected to continue shrinking, and there is a high likelihood that it will ultimately disappear by the end of the 21st century. The ongoing impacts of climate change pose a significant challenge to its preservation.
More about Quelccaya Ice Cap Retreat
- NASA Earth Observatory – Quelccaya Ice Cap
- NASA – Climate Change and Quelccaya Ice Cap
- University of Maryland, Baltimore County – Christopher Shuman
- Ohio State University – Lonnie Thompson
- Landsat Data – U.S. Geological Survey