Jakarta –
Researchers at Ohio State University have analyzed ice cores from Nevado Huascarán, the world’s highest tropical mountain, located in the central Peruvian Andes. Ice from these mountains reveals important climate records.
This study, which is the first to examine ice cores from this mountain peak, provides unprecedented insight into the climate history of the Amazon Basin over the past six decades.
Research focus
The research, supported by the National Science Foundation, focused on the analysis of four ice core samples. Two of them come from the mountain’s ‘pole’, namely the lowest point between two ridges, and two more come from its peak at an altitude of almost 7,000 meters above sea level.
As quoted from Earth.com, the research team then compared records of stable oxygen isotopes found in glacial ice at different heights on the mountain.
Stable isotopes of oxygen are used by scientists as a proxy to infer changes in temperature over time. However, interpreting these records in tropical regions can be challenging due to the complexity of the climate in these regions.
Critical insight
The findings reveal that the isotope record has a statistically significant relationship with sea surface temperatures in the Pacific and rainfall in tropical regions of South America.
In particular, isotopes from the peak show higher sensitivity to large-scale tropical Pacific sea surface temperature changes, compared with isotopes at lower elevations. These differences are important because they suggest that isotopic records at different elevations may reflect different aspects or mechanisms of regional climate history.
The study shows an increasing influence of the tropical Pacific climate on peak isotope records, most likely caused by rapid climate change in recent times.
El Nino year
“From a paleoclimate perspective, the data tell us that these cores may be useful for looking at the history of El Niño in the tropics,” said Austin Weber, lead author of the study and a PhD student at the Byrd Polar and Climate Research Center. “And we don’t have a good history of it because there aren’t many observational data sets or historical records about the tropics.
El Niño years, characterized by unusually warm sea surface temperatures in the equatorial Pacific, impact the Amazon Basin by weakening trade winds and reducing rainfall. These climate changes in turn affect the way isotopes are fractionated.
Impact of climate change
The study, published in the Journal of Geophysical Research, also highlights the impact of climate change on the region. Over the past 60 years, rising temperatures have contributed significantly to accelerated ice retreat on Nevado Huascarán.
The shrinking ice is concerning, said Lonnie Thompson, one of the study’s authors and a senior research scientist at the Byrd Polar and Climate Research Center.
He said that tropical ice core samples could act as important evidence for understanding Earth’s complex ocean-atmosphere system.
“The beauty of these ice cores is that they give you a perspective on natural variability before humans started changing the climate system,” Thompson said.
Historic achievement
The retrieval of these ice cores in July 2019 marked a historic achievement, overcoming decades of challenges posed by avalanches and snow-covered crevasses.
The team managed to reach the southern peak of the mountain and found glacial ice cores 471 meters long, both from the col drilling site (6,050 meters above sea level) and at the peak (6,768 meters above sea level).
“This is a very difficult and dangerous place to recover ice cores and the expedition will probably not be repeated,” Thompson said.
“This paper is the first published study of what I believe will be a series of papers on what may be the most unique collection of ice cores collected throughout my career,” he concluded.
Watch the video “The Largest Iceberg in the World Floating in Antarctica”
(rns/rns)
2024-01-21 07:03:28
#Worlds #Highest #Tropical #Mountain #Ice #Core #Reveals #Climate #History