Alpine Glacier, Unchanged for Thousands of Years, Now Melting: New Ice Cores Suggest Alps Have Been Strongly Warming Since 1980s

Dec. 11, 2013 — Less than 20 miles from the site where melting ice exposed the 5,000-year-old body of Ötzi the Iceman, scientists have discovered new and compelling evidence that the Italian Alps are warming at an unprecedented rate.

This evidence comes from a dried out leaf from a larch tree that grew several thousand years ago. A six-nation team of glaciologists led by The Ohio State University drilled a set of ice cores from Mt. Ortles in Northern Italy. The Alto dell’Ortles glacier did not show signs of melting for thousands of year. But not it is shifting from a below freezing temperature to one where the upper layers are at the melting point. The current atmosphere is warming outside of the normal range for millennia. The scientists say that this is consistent with the melting of glaciers at high elevations.

When they first started drilling in 2011, the first 100 feet of the glacier was like compacted snow that had partly melted. Below that, it was all solid frozen ice. This means that snow has been accumulating for years and has not melted until in the last 30 years, “which is when each year's new deposit of snow began melting.” They know that the ice has remained unchanged because of the larch tree that was mentioned earlier. It was wedged into the ice 240 feet beneath the surface and surrounded by solid ice.

"The leaf supports the idea that prehistoric ice is still present at the highest elevations of the region." The leaf is said to be around 2,600 years old.

The interest of the researchers is why the temperatures in the Alps are increasing at twice the rate of the whole earth. Alto dell’Ortles is located in the heart of Europe. It is one of the most populated areas of the world. They want to see if environmental changes can change climatic changes and Ortles gives them the opportunity to find that out.

Source:

http://www.sciencedaily.com/releases/2013/12/131211132447.htm

http://www.summitpost.org/mount-ortles/22174

Sea-Level Rise to Drive Coastal Flooding, Regardless of Change in Cyclone Activity

"Dec. 4, 2013 — Despite the fact that recent studies have focused on climate change impacts on the intensity and frequency of tropical cyclones themselves, a research team led by Jon Woodruff of the University of Massachusetts Amherst found on review of the relevant science that sea level rise and shoreline retreat are the two more certain factors expected to drive an increase in future flood risk from such storms."

Geoscientist Jon Woodruff along with his coauthors say that society must learn to live with a shoreline that is evolving and become more susceptible to flooding from hurricanes. The authors say that sea level rise and the potential it has to change coastlines is understudied therefore, this can result in catastrophic changes in flood risk associated with hurricanes. Woodruff says that there is a general agreement that there will be fewer hurricanes but that they will be more violent. The issue becomes that “there is less consensus on the magnitude of these changes, and it remains unclear how closely individual regions of tropical cyclone activity will follow global trends.”

Mr. Woodruff notes that the frequency and intensity of flooding will increase because the sea level is increasing as well. He says that the moderate rise of sea level is now over and that shorelines “are now beginning to adjust to a new boundary condition that in most cases serves to accelerate rates of shoreline retreat”. Mr. Woodruff and his colleagues say that a sea level rise of 1 meter in the NYC area would result in 100-year flood events that occur every 3 to 20 years. Most coastlines aren’t engineered to handle that frequency of flooding. They say that population centers are mostly on sedimentary coasts that will make the impact of future floods even greater.

Sources:

http://www.sciencedaily.com/releases/2013/12/131204132020.htm

http://www.wired.com/images_blogs/wiredscience/2010/11/Hurricane-Katrina.jpg

http://blog.newscom.com/wp-content/uploads/2012/10/rtrukonworld095682.jpg

Glaciers Sizzle as They Disappear Into Warmer Water

"Nov. 27, 2013 — Scientists have recorded and identified one of the most prominent sounds of a warming planet: the sizzle of glacier ice as it melts into the sea. The noise, caused by trapped air bubbles squirting out of the disappearing ice, could provide clues to the rate of glacier melt and help researchers better monitor the fast-changing polar environments." 

Erin Pettit, a geophysicist and researcher at the University of Alaska, would constantly hear popping and cracking sound when she would kayak in the northern waters. Underwater microphones that she had set up also picked up the sounds. She believed it to be the melting of ice but couldn’t confirm her theory. So she received help from Kevin Lee and Preston Wilson who are acoustic experts from the University of Texas. She sent them a chunk of glacier, which they mounted in a tank of chilled water. They recorded the audio and vide of the ice melting and matched the sounds of the recording to the escape of bubbles from the ice. Lee said that the bubbles make sound when they are being released by oscillating at a frequency between 1 – 3 kilohertz. He said that the smaller the bubble the higher the pitch would be.

Scientists have known for decades that bubbles form in glaciers when snow crystals trap air and then get squashed down under the weight of more snow. As more snow accumulates and compacts, it turns into ice and that air bubbles are pressurized. The bubbles form by even distribution within the ice. This is a way that can measure the rate of ice melting.

“Pettit and Lee say they could imagine using hydrophone recordings in glacial fjords to monitor relative changes in glacier melting in response to one-time weather events, seasonal changes, and long-term climate trends.” Sound travels a long distance underwater; therefore they are able to place microphones far underneath unstable sheets of ice to record sound. The audio recordings would complement other methods of measuring the rate of ice melting.

Sources:

http://www.sciencedaily.com/releases/2013/11/131127170103.htm

http://d1jrw5jterzxwu.cloudfront.net/sites/default/files/uploads/2012/06/Arctic-Ice-Alaska-web-size-97140096.jpg

http://blog.mixonline.com/briefingroom/wp-content/uploads/2012/02/Sound-Devices-and-Ambient-Recording-3.jpg

Volcano Discovered Smoldering Under a Kilometer of Ice in West Antarctica: Heat May Increase Rate of Ice Loss

"Nov. 17, 2013 — It wasn't what they were looking for but that only made the discovery all the more exciting."

In January 2010, a team of scientists set up a seismograph machine in West Antarctica. It was the first time scientists had placed instruments that would work year-round, even in the coldest parts of Antarctica. The machine measures disturbances created by earthquakes to make pictures of the ice and rock deep inside West Antarctica. The goal is to weigh the ice sheet and reconstruct Antarctica’s climate history. In order for them to do that, they would need to know how the mantle would react to a huge ice sheet. They needed to know whether the mantle was “hot and fluid or cool and viscous”. The seismic information will allow them to find out the properties of the mantle. Amanda Lough, a PhD student, found two seismic bursts in January 2010 and March 2011. She started to investigate the area. Eventually, it was found that there is a volcano forming a kilometer beneath Antarctica. “The discovery of the new as yet unnamed volcano is announced in the Nov. 17 advanced online issue of Nature Geoscience.”

At first, they didn’t know what was under Antarctica, but Lough noticed that what was under Antarctica resembled mountains. Soon, she realized that they were actually volcanoes. The seismic activities were low in frequency suggesting that they weren’t part of plate tectonics. They looked at airborne radar and observed that there’s elevation in bed topography in the same area where the seismic activities took place. They also showed a layer of ash buried under the ice. This layer was only found in the area where the volcano is located. The ash layer sets the age of the eruption at 8,000 years ago. They think that the ash might’ve come from Mount Waesche, but they don’t know when was the last time the volcano was active.

In Antarctica most mountains are not volcanoes, but that doesn't apply in West Antarctica. It's believe that there might be a hotspot under the volcano. It’s believed that the volcano will eventually erupt; they do not believe that the volcano will punch through a kilometer of ice, though. However, they do believe that it will melt a lot of ice, creating many lakes. This will increase the rate of ice-mass that is lost in West Antarctica.

Sources:

http://www.sciencedaily.com/releases/2013/11/131117155609.htm

http://upload.wikimedia.org/wikipedia/commons/9/93/Antarctica_major_geographical_features.jpg

http://en.wikipedia.org/wiki/File:MountSidleyWaescheMap.jpg