Posts by Weiye Zhang

Looking at Turkish Glaciers through Satellites

Posted by on Jul 28, 2015 in All Posts, Communities, Experiences, Featured Posts, Images, News, Science, Uncategorized | 0 comments

Looking at Turkish Glaciers through Satellites

Spread the News:ShareMore than half of the ice cover in Turkey has vanished since the 1970s, a mountainous country with an average elevation of 1,132 meters above sea level. Half of Turkey is covered by mountains and hills. Glaciers now exist on three volcanoes, in the high peaks in the Southeastern and Middle Taurus Mountains, and in the Eastern Black Sea Mountains. However, the glacier coverage was much larger in the 1970s, according to a study from Ege University in Turkey and NASA’s Goddard Space and Flight Center. Over more than 40 years, the total glacial area fell from 25km2 in the 1970s, to 10.85km2 in 2012-2013. Five of the glaciers have completely vanished. The research team, led by Doğukan Doğu Yavaşlı, professor at department of Geography at Ege University, updated the previous studies of Turkish glaciers from 1970s to 2012-2013, and published their findings in Remote Sensing of Environment. The researchers observed the decline of Turkish glaciers via Landsat satellite data. The Landsat program delivers the longest continuous global record of the Earth’s surface. Since the 1970s, Landsat satellite and its successors have provided consistent and stunning images of the Earth for researchers and scientists to closely measure changes in the Earth’s landscape. Landsat sensors are characterized by moderate spatial resolution—course enough for global coverage, and clear enough to capture large-scale human activities such as urbanization.   From the Landsat images showing Mount Süphan, a dormant volcano, the glacial part over the mountain has shrunk more than 70% since the 1970s. The current remnant glacier is so small and fragmented that it is challenging for scientists to distinguish the ice from debris. The ice cap on Mt. Ağrı is the highest (5,137m) and largest glacier in Turkey, which we have covered in a previous Photo Friday. located along Turkey’s eastern border, Mt. Ağrı is also known as Mt. Ararat, the national mountain of Armenia, where it was located until World War I and where it still plays a significant role in culture. Through interpretation of the satellite data, the researchers discovered that from 1977 to 2013, most glacial retreat took place on the southern, western and eastern glacier aspects, all at lower elevations. Ice loss on the northern part is comparatively minimal.   Most glacial retreat can be attributed to climate change and its impact on rising summer nighttime and minimum temperatures, the researchers found. They found that there were no variations in precipitation or cloud cover that could explain the high rates of glacier retreat since the 1970s. The combination of Landsat and commercial satellite data greatly improved the study of glacier change as well as climate change implications in Turkey during this period. “Without Landsat’s long record, studies like ours would be impossible to undertake, because we don’t have a time machine to go back to the 1970s and 1980s and see how Turkey’s glaciers were doing then. Using Landsat and commercial satellite data together, we can map glaciers with high accuracy. It’s a powerful combination for studying the Earth from space,” said Compton Tucker, one of the researchers of the study. Spread the...

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Alaska Mountain Glaciers Raise Global Sea Level

Posted by on Jul 22, 2015 in All Posts, Communities, Experiences, Featured Posts, Images, News, Science | 0 comments

Alaska Mountain Glaciers Raise Global Sea Level

Spread the News:ShareAlaska’s impact on global sea level rise is becoming more pronounced. Its melting glaciers, particularly the minority mountain glaciers, will be a major driver of sea level change in the coming decades, according to a new study conducted by Chris Larsen, research associate professor at the University of Alaska Fairbanks, and his colleagues. With over 100,000 glaciers, Alaska is home to half of the world’s glaciers. Every seven years, glacier loss from Alaska contributes a 1-foot thick layer of water covering the state of Alaska. Though mountain glaciers hold less than 1% of the total glacier volume on the Earth, the recession of mountain glaciers contribute to nearly 1/3 of current sea level rise. Larsen and his team examined 116 glaciers across Alaska to estimate ice loss from melting and iceberg calving between 1994 to 2013. Iceberg calving, the unique process of ice chunks breaking off at the edge of a glacier, is underlined in the study because few existing observations or models value the impact of iceberg calving under climate change. “We’ve long wondered what the contribution of iceberg calving could be across the entire state,” O’Neel, one of the researches, told the American Geophysical Union.  The Columbia Glacier in Prince William Sound has retreated more than 12 miles mostly due to iceberg calving since 1980. The University of Alaska Fairbanks collected airborne lidar altimetry data, highly specialized research aircrafts, as part of NASA’s Operation IceBridge mission since 2009. The mission aims to picture the Earth’s polar ice in unprecedented detail with innovative science instruments to better connect the polar regions with the global climate system. The team also integrated the new data with information from the 1990s collected by the University scientists and Keith Echelmeyer, a pilot, mountaineer and pioneer glaciologist. They developed a more detailed characterization of the size and shape of every glacier in Alaska, in addition to the glaciers of southwest Yukon Territory and coastal northern British Columbia. With the new data inventory, the research team has made some significant discoveries. Across the years from 1994 to 2013, Alaska’s tidewater glaciers contributed to only 6% of Alaska’s mass loss. Glaciers that end in the ocean, called tidewater glaciers, make minimal contribution to sea level rise, while glaciers ending on land are primary contributors to mountain glacier mass loss driven by climate change. “This work has important implications for global sea level projections. With improved understanding of the processes responsible for Alaska glacier changes, models of the future response of these glaciers to climate can be improved,” Larsen told the American Geophysical Union. Despite the fact that the impact of the large-scale tidewater glacier losses in Alaska is negligible, Alaska will remain a major contributor to global sea level rise through its mountain glaciers. Spread the...

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Roundup: the Glacier Run, Models, and Georgia Glaciers

Posted by on Jun 15, 2015 in Adaptation, All Posts, Art/Culture, Communities, Experiences, Featured Posts, Images, News, Policy and Economics, Roundup, Science, Tourism | 0 comments

Roundup: the Glacier Run, Models, and Georgia Glaciers

Spread the News:ShareThe Glacier Run The 8th Glacier 3000 Run and Gstaad Kids Run will take place on Saturday, August 8, 2015. The racecourse passes through a beautiful alpine landscape offering both runners and spectators many spectacular views. Between the starting point on the Gstaad Promenade at 1’050 meters and the finish line at Glacier 3000 (2’950 meters) lie 26 kilometers. Read more about the events here.   Glacier Retreat Model Glaciers are crucial in many countries where meltwater from glaciers is an important source of water for drinking water supply, irrigation, hydropower generation and the ecological system. Glaciers are also important indicators of climate change. They have been significantly altered due to the global warming and have subsequently affected the regional hydrological regime. However, few models are able to parameterise the dynamics of the glacier system and consequent runoff processes in glacier fed basins with desirable performance measures. Read more here.   Glacier changes in Georgia Considering its size, Georgia has a large number of glaciers. In the mountains of Georgia, there are about 786 registered glaciers, with a total area of about 550 km. About 82.5 % are in the upper courses of the Kodori, Inguri, Rioni, and Tereck rivers. For the past 150 years, significant glacier retreat (0.8–1.7 km) and shrinking of their area by 16 % has been observed. Read more here. Spread the...

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Photo Friday: Mount Adams

Posted by on Jun 5, 2015 in All Posts, Art/Culture, Featured Posts, Images, Tourism, Uncategorized | 0 comments

Photo Friday: Mount Adams

Spread the News:ShareMount Adams, the second highest mountain in the U.S. state of Washington, is a potentially active volcano in the Cascade Range. Mount Adams was active from about 520,000 to about 1,000 years ago. During the past million years, it has generated considerable eruptive materials. Mount Adams is also home to 12 officially named glaciers. Most of the glaciers originate from the mountain’s summit ice cap. Roger Reeves and Terrie Heslop began their photography journey with film cameras back in the 1970s and continued until the digital revolution. As a happily married couple, they explore the world around them and share the beauty of natural landscape. The pictures they took in Mount Adams are absolutely breathtaking. See more about the pictures taken by Roger Reeves and Terrie Heslop here. Sleeping Beauty Volcano Hidden Majesty Sheets of Ice Mount Adams Forest Road (photo credit: Roger Reeves and Terrie Heslop)   Spread the...

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Glaciers Shape Lives in Upper Hunza

Posted by on Jun 2, 2015 in Adaptation, All Posts, Communities, Featured Posts, Images, Policy and Economics, Science, Uncategorized | 0 comments

Glaciers Shape Lives in Upper Hunza

Spread the News:ShareGlacier and river dynamics shaped irrigation systems and land use practices in Pakistan since the late 1700’s, according to a new paper by Sitara Parveen and his colleagues. These systems and practices can still be observed hundreds of years later, but they face severe challenges from glacier retreat. Upper Hunza is located in the western Karakoram, Pakistan. The Hunza River flows north to south, and is joined by the Shimshal River from the northeast, and by the Batura, Passu, Ghulkin and Gulmit glaciers from the west. The melt runoff from the four glaciers supports approximately 20,000 people in Upper Hunza, and nurtures crops and orchards cultivated by villagers. Steady and stable agricultural production requires constant and sufficient melt-water supply from glaciers and snowfields. The interactions between hydrological conditions and human communities in Upper Hunza are characterized by various aspects, including the arid environment of human settlements at lower altitudes, the dynamics of snow and ice cover at higher altitudes, the flexible water use practices, and diverse socio-economic conditions. Upper Hunza is well known for its sophisticated irrigation systems. The earliest recorded irrigation channels in the valley date back to at least 1780 and diverted water from the Batura Glacier. To study the impacts of environmental and socio-economic dynamics on irrigation systems, Parveen and his colleagues examined the irrigation systems in three villages—Passu, Borith, Ghulkin—which are fed by different water sources. In Passu Village, the largest settlement is located on three fluvial terraces at an elevation of about 2500m above sea level. Over the past 400 years, natural disasters have driven villagers to higher ground. They have also made several attempts to recover and rehabilitate barren land for crop cultivation. In 1983, a project to expand irrigable land was implemented by sourcing water from the Batura Glacier, however, the operation of this project was disturbed by the ups and downs in the volume of melt-water. Despite that, each household received one field on each terrace and 53% of the project area is transformed to irrigated fields. In Borith, the main water sources are the Passu and Ghulkin glaciers. The community has made efforts to secure access to water due to frequent water crisis caused by glacier retreat since the 1950s. The northern part of Borith used to be served by Lake Ghyper Zhui, which began to shrink in the 1940s as the Passu Glacier started to become thinner with melting. Several attempts were then made to conserve the melt water flow into the lake, with the expansion of natural irrigation channels through daily excavation works. However, all the efforts turned futile as soon as the glacial runoff proved to be insufficient and the land returned to a barren state. Lower Borith sources all of its water from Ghulkin Glacier. Since 1960, many channels have been constructed, adjusted and constantly maintained to divert water in response to the continuous thinning of the glacier, which is highly labor-intensive. As the majority of households migrated from the community due to ongoing declining water resources, an increasing number of fields have gone idle. New pipelines were installed in 2013, but the problem of shifting water sources still remains. Ghulkin is located between two glaciers—Ghulkin and Gulmit. The village is also facing water shortage due to increasing glacier down-wasting. The problem is even more aggravated by the dispute over water use rights between the original inhabitants and the relatively new immigrants. A water management committee was thus established, but does not function well because the original settlers upstream often ignore the arrangement, leaving the downstream people helpless. Some villages constructed new irrigation channels and cultivated different, drought-tolerant...

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