Tag Archives: Climate

Video: NOVA’s ‘Secrets Beneath the Ice’

In early 2002, a Manhattan-sized chunk of ice broke off the Larsen Ice Shelf in Antarctica. The 200-meter-thick ice disintegrated into the ocean a short time later. In 1995, a 770 square mile ice section also broke away and disintegrated from the Larsen Ice Shelf.

These events have alarmed climatologists, geologists, and environmental scientists, wondering if we are headed to an ice-free Antarctica. It is speculated that if all the ice in Antarctica melts, this would cause global sea level rises, so high that New York City would be inundated up the level of the Statue of Liberty’s shoulders.

An easy way to understand sea level rise is to place a drinking glass on your table, fill it with enough ice cubes so that they stick out from the rim of the glass, and then fill the glass with water just below 1cm from the rim. As you stare at the glass, eThe size of Antarctica compared to the U.S.verything will appear stable. But as the ice responds to the room temperature, it will slowly melt, and the meltwater will increase the volume of the existing water causing it to rise. About an hour or two later, your ice would have completely melted leaving you with  a small pool of water surrounding the base of the glass. Simply visualize this on a larger scale; think of the ice cubes as large Antarctic ice shelves, the water in the glass as ocean water, and like the ice cubes responding to the room temperature, think of the Antarctic ice shelves responding to the global climate temperature. The table can act like coastal cities, with the rising water flooding them. The photo give a perspective on how big Antarctica is compared the U.S.

This video focuses on the efforts of ANDRILL, a  geological drilling project with a collaboration of scientists who seek to understand the paleo-environmental changes in Antartica from rock cores, which may yield clues for the future.

Geology and Archaeology – A Collaborative Example.

Nevado Coropuna

In the shadows of Nevado Coropuna—Peru’s tallest volcano—geologist Gordon Bromley quietly hacks away at glacial deposits. He is collecting samples from boulders that skated down the mountain during the last ice age. These samples will be processed by a technique called surface exposure dating. In a concerted project with Columbia University’s Lamont-Doherty Earth Observatory, they will isolate the tiny grains of the 2mineral pyroxene to measure its helium isotopes. This will be crucial to reconstructing the ebb and flow of ice on Nevado Coropuna since the last ice age, to understand when glaciers on Coropuna advanced and retreated, how the tropics influenced the global climate system, and agricultural impacts in the area.


The Rock Shelter
The Rock Shelter

 Kurt Rademaker, an archaeologist from the University of Maine, helps Bromley with geology work. During a five hour walk into a lava field, they discovered stones that were clearly not natural deposits. It turned out to be an ancient Andean road. At roughly 15,000 feet, they further discovered a prehistoric rock shelter – the highest ice age archaeological site known thus far. Rademaker has found evidence of human activity that reaches back to the end of the last ice age. He has found numerous artifacts that were radio carbon dated to 12,000 years ago and based on archaeological evidence, he suggests that the last event in the shelter was cooking before the inhabitants hurriedly left the site.

6Together with glacial geologic chronology, they are establishing precisely when humans occupied and unoccupied the site. This will shed understanding on why those humans left – what were they responding, a change in the local environment? So far, their research findings challenge conventional thinking that the climate was too cold for early hunter-gatherers to survive.

4The concerted project seeks to understand the past climate better, along with wanting to understand what adaptation measures may help humans survive in this hotter world. Archaeology in collaboration with geology will help answer such questions. Archaeology can provide another layer of evidence in reconstructing the ebb and flow of ice on Coropuna. While geology seeks to understand paleo-climate to understand the future and impact on humans, archaeology can yet provide supporting evidence on how climate impacted past humans.

1Coropuna has seen the dissipation of snow twice, once in the last ice age, and in modern day. Temperatures are rising due to industrious carbon dioxide in the air.  Coropuna is changing again. It has lost a quarter of its glacier mass since the 1960s. Millions of humans rely on glacial water and water in the arid region is expected to grow even scarcer. Understanding the ebb and flow of Coropuna’s glaciers in the past will be a key to understanding how a rapidly warming climate will impact water availability in the future. Research is still ongoing.

-antonio kuilan

Lamont-Doherty Earth Observatory – Columbia University Earth Institute. Climate in the
Peruvian Andes: From Early Humans to Modern Challenges.
June 2, 2013. Web.