Ice fields in southern South America are rapidly losing volume and in most cases thinning at even the highest elevations, contributing to sea-level rise at "substantially higher" rates than observed from the 1970s through the 1990s, according to a study published Wednesday.

The rapid melting, based on satellite observations, suggests the ice field's contribution to global sea-level rise has increased by half since the end of the 20th century, jumping from 0.04 millimeters per year to about .07 mm, and accounting for 2 percent of annual sea-level rise since 1998.

The southern and northern Patagonian ice fields are the largest mass of ice in the southern hemisphere outside of Antarctica. The findings spell trouble for other glaciers worldwide, according to the study's lead author, Cornell University researcher Michael Willis.

"Patagonia is kind of a poster child for rapidly changing glacier systems," he said in a statement. The region, he added, "is supplying water to sea-level at a big rate compared to its size."

The study was published in the journal Geophysical Research Letters.

Melting glaciers, both in South America and the Himalaya, are a major concern to populations downstream who depend on the ice fields as a reservoir providing a steady summer water supply for drinking and agriculture.

Scientists suspect the Andes, for instance, have already surpassed "peak water" and that hundreds of thousands of people living downstream of the glaciers in Peru and Ecuador now face a future of lower flows and increased variability in local rivers.

The new study compared satellite imagery from two different missions over a 12-year period starting in 2000. On average, they found, the Southern Patagonian Icefield glaciers thinned by about six feet per year during that period.

Some glaciers were stagnant; others even advanced slightly, Willis said. "But on the whole, retreat and thinning is prevalent."

Warming air temperatures contributed to the thinning throughout the mountain range, Willis noted. And the warmer temperatures increased the chances that rain – as opposed to snow – would fall on and around the glaciers. That double threat increases the amount of water under the glaciers, decreasing friction and moving more ice to the oceans, he said.

Other researchers said the new study could provide valuable information for future predictions, said Alex Gardner, an assistant professor at Clark University in Massachusetts, who was not involved in the study but researches glaciers and ice sheets.

"A study like this really provides a strong data set to validate and calibrate glacial models," he said in a statement.

This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.

9 Comments

1. 1. parobinson in reply to geojellyroll 07:47 AM 9/7/12

   geojellyroll, you really should get out a little more often.

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2. 2. G. Karst 12:06 PM 9/7/12

   High altitude ice accumulation is a function of precipitation (snowfall). I would like to see precipitation and temperature data, so that meaningful, conclusions can be made. Where are the simple graphs, showing constant precipitation and significant temperature increases on the summits and alpine vestigial ice fields?
   
   When people withhold data, it is usually for ideological purposes. Verification is what science is all about. GK

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3. 3. cybersleauth 09:52 PM 9/7/12

   Wait for Spring And Summer To Come.
   http://www.viewcrafters.com

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4. 4. moss boss 04:24 PM 9/8/12

   @Geo:
   
   Where do you live; Kansas?
   
   This is a graph of measured sea level rise:
   
   http://en.wikipedia.org/wiki/File:Trends_in_global_average_absolute_sea_level,_1870-2008_(US_EPA).png
   
   This an example of the prediction of what may happen if the trend continues:
   
   http://www.indiawaterportal.org/node/6478
   
   Maybe you are living in a cave in Kansas.

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5. 5. thinkitthrough in reply to geojellyroll 12:01 AM 9/10/12

   Geo, perhaps you are unaware of the Maldives, an island nation in the Pacific that is about to be inundated because they are so low-lying. Maybe you have never heard of sea water slowly infiltrating coastal water systems, higher storm surges, erosion of beaches. But "I haven't seen it" does it equal "it doesn't exist". Ever.

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6. 6. Sisko in reply to moss boss 10:39 AM 9/10/12

   LOL---so less than 1 foot of sea level rise per 100 years is a disaster in your evaluation????

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7. 7. G. Karst in reply to thinkitthrough 11:10 AM 9/10/12

   Last I heard, the Maldives had increased their land surface area. Perhaps you should show actual data for this so called inundation, you speak of. Maybe, you are referring to a politician's expressed concern that the islands may capsize... LOL.
   
   Think - it - through... those that build on flood plains can expect WHAT during interglacial warm periods. The longer a interglacial warm period lasts, the more ice reservoirs will shrink and the higher MSL, will be (over centuries). It has been ongoing now for 12,000 years.
   
   Some irrational people actually think we would be better off, with a return of the ice age glaciation. They regard humans as vermin, a parasite which must be culled, for the benefit of gaia. I hope you are not one of those. GK

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8. 8. 2008RealityCheck in reply to G. Karst 05:46 PM 9/12/12

   Read the Stanford U. report at http://paos.colorado.edu/~whan/ATOC4800_5000/Materials/Morneretal_2004_maldives.pdf regarding the Maldives sea level. Sea level is lower in the Maldives than in the recent past. I incorporated this study into my novel, The Carbon Trap.

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9. 9. 2008RealityCheck 05:54 PM 9/12/12

   Here's another http://www.spiegel.de/international/world/south-pacific-islands-threatened-by-more-than-just-rising-sea-levels-a-838675.html.
   
   "Environmentalist organizations have used images from South Pacific islands to illustrate the disastrous effects of rising sea levels. But a group of French researchers has found that the problem is much more complicated: The islands are also being pulled under by shifting tectonic plates." "That the UN had been premature in declaring the villagers on Tegua to be climate change refugees became clear when a large earthquake caused the island to shoot back out of the water in 2009. "The coconut plantation has been on dry land since then,"

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