Posts by Yunziyi Lang

Iceberg Calving Boosts Methane Emissions

Posted by on Jul 16, 2015 in All Posts, Featured Posts, Science | 0 comments

Iceberg Calving Boosts Methane Emissions

Spread the News:ShareThe substantial increase in methane concentrations in tropical wetlands can be attributed to the last Glacial Period, when icebergs calving off North America introduced massive influxes of fresh water into the North Atlantic, new research shows. Calving of glaciers in the North American ice sheet, also known as Heinrich events, released large icebergs into the North Atlantic Ocean. The authors of this new study, Rachael H. Rhodes and her colleagues from Oregon State University, found that Heinrich events in the Hudson Strait may have enhanced rainfall in the Southern Hemisphere, which in turn led to increased methane production in tropical wetlands when the wetlands flooded. “Essentially what happened was that the cold water influx altered the rainfall patterns at the middle of the globe. The band of tropical rainfall, which includes the monsoons, shifts to the north and south through the year,” Rhodes explained during an interview with Ed Brook, a professor at Oregon State University. “Our data suggest that when the icebergs entered the North Atlantic causing exceptional cooling, the rainfall belt was condensed into the Southern Hemisphere, causing tropical wetland expansion and abrupt spikes in atmospheric methane,” she added. According to the study, each individual Heinrich event could have long-term impacts on tropical climate and hydrology, specifically over 740 to 1520 years. Four specific Heinrich events were linked to methane signals. Each of these events deposited “relatively thick and spatially extensive sediment, which was rich in detrital carbonate.” With a newly developed continuous measurement technique, Rhodes and her colleagues produced an accurate record of atmospheric methane concentrations for West Antarctic Ice Sheet Divide ice core in high resolution. More importantly, they detected methane emission anomalies in Southern Hemisphere. “Using this new method, we were able to develop a nearly 60,000-year, ultra-high-resolution record of methane much more efficiently and inexpensively than in past ice core studies, while simultaneously measuring a broad range of other chemical parameters on the same small sample of ice,” said Joe McConnell from Desert Research Institute in Reno, Nevada, who contributed to perfecting the measurement technique. The findings could have implications for better understanding greenhouse gas emissions and the impact of past glacial calving on climate change. Spread the...

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Icy Adventures in Norway

Posted by on Jun 24, 2015 in All Posts, Featured Posts, Tourism | 0 comments

Icy Adventures in Norway

Spread the News:ShareIf you want to walk and climb on glaciated areas for an extraordinary experience, you should visit Norway before the glaciers melt away. You do have some decades ahead, though, before glaciers really become scarce there. Still, rising  temperatures have caused a dramatic decrease in glacial volume in Norway as in other parts of the world. As this trend intensifies, glacier tourism will be largely limited in the future. There are many opportunities to explore glaciers. There are over 1600 glaciers in Norway, which cover an area of roughly 2600 square kilometers. Most of the glaciers are in mountainous regions along or near the coast, particularly in southwestern and northern Norway. You could choose among guided day tours, longer tours, glacier surface walks, glacier lake kayaking, terminal face walks, ice climbing, and more. But climate change will change the nature of glacier tourism. A 7-year follow-up study conducted by Trude Furunes and Reidar J. Mykletun considered five components of the development of glacier tourism: natural resources, access, demand, entrepreneurship, and the need for skilled delivery of tourism services. Data in the study was collected through analysis of websites, repeated interviews, and participant observation. Most glacier tourism activities involve the edges of the glacier, especially the glacier arm area, which are neither too steep nor too dangerous to enter. Glacier tourism generally occurs from June to August, when snow accumulated during winter has finished melting. A large portion of the study’s respondents expressed concern about impacts of climate change on glacier recession. After all, ice melting limits the accessibility of glaciers. In 2003, some operators decided to include more mountain walks in the tour package due to ice melting, which in the end led to dramatic decline in clients. In 2007, as some glaciers became inaccessible, some operators had no choice but to move to different glaciers in order to minimize financial loss. Low entry cost attracted many investors into the glacier tourism business, causing a great deal of competition in the region. “Several activity companies pop up. But the Briksdal glacier is now closed due to the reduced glacier area, which makes it difficult to run safe glacier guiding here. This has led to increased tourism on the Nigard glacier,” said one respondent. More and more companies chose to tailor activities for their clients instead of providing highly commercialized products. “Competitors still exist, but they have changed their activity,” said another respondent. Many operators claimed that they treated safety as priority and few accidents had occurred. “We focus strongly on safety, and use two guides per group, where one is certified. We also focus on equipment needed. It is important that the clients don’t perceive high risk, but get a unique experience.” Another operator stated that, “we have had no accidents, only bone fractures.” According to T. Furunes and R. J. Mykletun, there was a 30% decrease from 2003 to 2009 in the number of visitors and operators, due to decline in natural resources and access. However, they suspected that relatively rapid melting of glaciers in Central Europe would likely to prompt glacier tourism in Norway. In a sense,  glacier loss in Central Europe could make Norwegian glacier tourism seem more attractive.  This study thus confirms the uneven and complex effects of global warming and its consequences for glacial retreat on national tourist industries. Spread the...

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PhotoFriday: Kali Moves Into New Home

Posted by on Jun 12, 2015 in All Posts, Featured Posts, Images, News | 0 comments

PhotoFriday: Kali Moves Into New Home

Spread the News:ShareMcDonnell Polar Bear Point of the Saint Louis Zoo welcomed its first occupant – Kali on May 5, 2015. Kali is a two and half year-old, 850-pound orphaned male polar bear. He was turned over to US Fish and Wildlife Service (USFWS) after his mother was killed by an Alaska Native hunter. His new home is located adjacent to Penguin and Puffin Coast at the Zoo, where a large dive pool is bounded by expansive split view windows. “This wonderful habitat shows our commitment to protecting polar bears, which are declining in the wild and are highly vulnerable,” said Jeffrey P. Bonner, Ph.D., Dana Brown President and Chief Executive Officer of the Saint Louis Zoo during interview with the Intelligencer. “By working to not only conserve polar bears in the wild but to offer a wonderful habitat for breeding and caring for bears, we can help save these iconic animals.” Let’s take a peak at how Kali explores his new home at Saint Louis Zoo. As you know, sea ice is crucial to polar bears in terms of survival. Polar bears take advantages of ice floes and breath holes when hunting seals or fish. Dramatic sea ice reductions resulted from increasing temperature has lead to rapid decline in polar bear population. Moreover, polar bears also make use of icebergs which are formed from calving glaciers. The Inuit, indigenous inhabitants of the Arctic, recognize this association between polar bears and icebergs. Aiming to reduce its carbon footprint, the Saint Louis Zoo has carried out sustainable practices. In addition, it tries to promote sustainable behaviors among visitors. Here are some photographs of polar bears. Source: Richard Roche/Flickr Source: TomD./Flickr Source: rubyblossom./Flickr Source: Valerie/Flickr Source: Valerie/Flickr For more information about the Saint Louis Zoo and Kali, visit here.   Spread the...

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New Cyanotoxins Surface in Polar Region

Posted by on Jun 3, 2015 in All Posts, Featured Posts, Images, News, Science | 0 comments

New Cyanotoxins Surface in Polar Region

Spread the News:ShareDeath by cyanobacteria-made microtoxins is not pleasant. The toxins damage the nervous system, especially anatoxin-a, also known as a Very Fast Death Factor. As the global temperature increases, concerns about the range of these toxins are growing. For the first time, anatoxin-a has been found as far north as the polar regions, according to a new paper by Ewelina Chrapusta, a PhD candidate in molecular biology at Jagiellonian University, in Krakow, Poland, and her colleagues. They revealed that some cyanobacteria were capable of combining different types of toxins, in particular microcystins and anatoxin-a. According to G. Zanchett and E.C. Oliveira-Filho, global climate change is anticipated to lead to the rapid development of hazardous cyanobacterial species with “increasing growth rate, dominance, persistence, geographical distribution, and activity”. In particular, glacier melt will provide more suitable habitats for cyanobacteria and lead to higher production of cyanobacterial toxins in the polar region. Microcystins and anatoxin-a are produced by freshwater cyanobacteria. Their high toxicity makes them a serious threat to other organisms, including livestock and humans. According to J. Patockaa and L. Stredab, these toxins act extremely rapidly and could cause death in minutes or hours, depending on the dose. In 1996, the first outbreak of cyanobacterial toxins poisoning occurred in Caruaru, Brazil, killing 76 patients from liver failure. Another episode happened in Brazil in 2000, which involved 2000 cases of stomach flu and 88 fatalities within roughly 40 days. These toxins are recognized as secondary metabolites. They allow the cyanobacteria to flourish under nutrient-rich conditions and reproduce exponentially. Cyanobacteria are the most significant component of microbial and plant communities, especially in polar ecosystems, because they can provide microhabitats for other organisms. Specifically, they create a cohesive and diverse biocrusts on moist soils and in freshwater reservoirs of nutrient-poor habitats, especially glacial moraines. The biocrust serves as shelter for a variety of organisms, including rotifers, fungi, green algae, and viruses. Even though the ability of crust-forming cyanobacteria to produce toxins has been well demonstrated in temperate and tropical regions, the “ecological role of cyanotoxins in polar ecosystems is poorly understood,” according to Chrapusta. As a result of global warming, increased frequency of cyanobacterial blooms pose severe threats to human health in communities worldwide, especially those that rely on glacier melt-water to live. Chronic exposure to cyanobacterial toxins in humans could increase the risk of organ damage, which may develop into cancer. More research is needed to fully understand the extent to which rising global temperatures will influence cyanobacteria populations and their ability to produce toxins in the future. Moreover, specific species of cyanobacteria, which combine microcystins and anatoxin-a, need to be identified so that the distribution of such toxins could be monitored and projected accurately. In any case, the detection of anatoxin-a at high latitudes is a serious warning sign of possible dangers that may come in the future. Spread the...

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Photo Friday: Cryoconites and Glacier Tables

Posted by on May 29, 2015 in All Posts, Featured Posts, Images, Science | 0 comments

Photo Friday: Cryoconites and Glacier Tables

Spread the News:ShareHave you ever seen dark cavities on glaciers, which are also referred to as “cryoconites”? These holes, which can be meters deep,are created from debris on top of glaciers. Dark-colored debris, including soot, dust, and pollen, speed up the melting process of glacial ice as a consequence of their low reflectivity to incoming sunlight. In some cases, glacial surface debris can also form pits in the ice through chemical melting. Hence, most of the glacial thaw holes are filled with melt-water, which become home to cyanobacteria, fungi, and other microbes. However, some large solid debris, in particular boulders, will prevent the ice beneath from melting as surrounding ice, forming glacier tables. Here are some photographs of cryoconites and glacier tables. Learn more about glacial surface debris here.   Glacier Table ©2010 Florian Mair Glacier Thaw Hole Source: Galia & Yoav/Flickr Cryoconites Source: Sandwich/Flickr Glacier Thaw Hole Source: Andrew E. Russell/Flickr Spread the...

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