Photo Friday: Totten Glacier Twitter Feed is Pun-derful

East Antarctica’s Totten Glacier has got some amazing social media presence. The Twitter account ‘Totten Glacier’ provides updates on relevant glacier news, while also offering some punny first-person commentary, adding a playful and refreshing spin to climate change research.

The account refers to the glacier as “old timer” and “sleeping giant”, as Totten is one of the biggest glaciers in the region. The glacier is so massive that it holds enough ice to raise global sea levels by about 3 meters.

According to NASA Jet Propulsion Laboratory, East Antarctica is relatively stable compared to the rapid melting in the western portion. However ice loss in the region has been substantial in the recent years.

In a recent story by Phys.org, a study obtaining data through new satellites reported significant ice loss from the Totten Glacier region. Approximately 1.4 billion tons of water have been lost in the last decade. Scientists from the study believe this to be just the beginning of serious change to the ice sheet.

East Antarctica coastline (Source: Nasa JPL)

Click below to check out a time lapse video by Google Earth demonstrating the recession at the foot of the glacier since 1984.

Totten Glacier recession (Source: Google Earth/YouTube)
INSH tweets that Totten Glacier loses 63-80 billion tons of ice annually (Source: INSH/Twitter)

Read More on GlacierHub:

Ancient Humans of Glaciated Western China Consumed High-Potency Cannabis

Mountain Context Matters in Monitoring and Reporting on Sustainable Development Goals

Rising Temperatures Have Doubled Himalayan Glacier Melt—Study

Please follow, share and like us:
error

Observing Glacier Calving through Time-Lapse Imagery and Surface Water Waves

A recent paper published in the Journal of Glaciology explores how a team of researchers studied waves in a Patagonian lake to detect glacier calving events at Glaciar Perito Moreno. Calving events occur when an iceberg detaches from the glacier front. Such events produce waves of different magnitudes as the glacier discharges into the ocean or an adjacent lake.

The paper’s lead author, Masahiro Minowa, told GlacierHub that while calving plays a key role in the recent rapid retreat of glaciers around the world, many processes related to calving are still poorly understood because direct observations are scarce and challenging to obtain.

An example of a glacier calving event producing surface tsunami waves (Source: Masahiro Minowa)
An example of a glacier calving event producing surface tsunami waves (Source: Masahiro Minowa).

Minowa and his team employed a creative methodology to observe calving events at a distance. Employing four time-lapse cameras and a water pressure sensor, they conducted fieldwork in three separate time periods, roughly one week to three weeks long between 2013 and 2016. 420 events were noted within this relatively short period of time. They also estimated the calving volume using the time-lapse images and maximum wave amplitude.

“We did our field works twice in summer and once in winter so that we could observe the seasonality of calving activity. We also wanted to understand mechanisms driving calving if there are any,” Minowa said.

The researchers categorized the time-lapse images by separating calving events into four groups: 1) Topple, an ice tower toppling into the lake; 2) Drop, an ice block dropping into the water; 3) Serac, a small piece of serac slipping down to the lake; and 4) Subaqueous, an underwater iceberg detachment that floats up to the lake surface.

Illustration of the most common calving types at the study site (Source: Minowa et al)
Illustration of the most common calving types at the study site (Source: Minowa et al).

These images were then scrutinized in great detail. For example, Topple and Drop events were distinguished based on whether crevasse widening occurred; while Subaqueous was differentiated from other subaerial events by noting a relatively large single iceberg appearing without any geometrical change on the glacier front and a lack of sediment inclusion on the surface.

The surface wave profiles corresponding to the events were also examined. Their signals were more complex, making it difficult in some cases to distinguish events on the basis of wave profiles alone.

“Initially, we expected a clear difference in wave frequencies between subaqueous and subaerial events. While we could see some difference in frequencies, we are unsure if this is a result of different calving style,” Minowa explained. Wave frequencies also vary based on the relative location of the event to the sensor, even if it is the same calving style. A larger sample of cases is thus required to confirm the wave patterns associated with different calving events.

However, Minowa stressed the importance of choosing a strategic location for the water pressure sensor, which vastly affects the results and findings of a glacier calving study. He warned that a problem may arise from the instrument’s location. “Since waves’ amplitude decay with distance, you will not be able to detect all of the calving events if you place the sensors too far. So, you need to be close enough to the glacier, and you will easily detect many of them,” he said. Yet, this might limit the scope of the area studied, requiring a balanced consideration.

Examples of the time-lapse camera images (Source: Minowa et al)
Examples of the time-lapse camera images (Source: Minowa et al).

From the data, the team could see the seasonality of calving activity. Their results showed that calving events were 2.6 times more frequent during the austral Summer (December-March) as compared to Spring (October). Subaerial calving events occurred 98 percent of the time, although Minowa conceded that the dataset was a bit short to confirm any trigger mechanisms.

Following the research, the team is now ready to install new water sensors for a year-round measurement around the glacier in the hope of further understanding calving processes through the use of surface-waves in glacier fronts. This is a step toward reducing glacier melting in Patagonia and the rest of the world.

Please follow, share and like us:
error

James Balog: Breathing Life Into Ice

James Balog. © James Balog
James Balog. © James Balog

For more than 30 years, James Balog, an American photographer, has devoted himself to merging insights from art and science to create innovative and vivid interpretations of our changing world. His photographic interests are diverse, including endangered animals, North America’s old-growth forests, and polar ice.

In 2007, Balog initiated a long-term photography project, called the Extreme Ice Survey (EIS), which offers visual evidence of the Earth’s changing ecosystems. On the one hand, EIS is a substantial portfolio that documents the beauty and architecture of ice. On the other hand, it is time-lapse proof of extreme ice loss. So far, 41 solar-powered cameras have been deployed at 23 glaciers in Antarctica, Greenland, Iceland, Canada, Austria, Alaska, and the Rocky Mountains of the U.S. The glaciers are recorded every 30 minutes, year round, during daylight. The time-lapse images are then edited into videos that unveil an incremental record of climate change.

National Geographic magazine showcased the Extreme Ice Survey project in June 2007 and June 2010. The project is also featured in the renowned documentary, Chasing Ice, which won an award for Excellence in Cinematography at the 2012 Sundance Film Festival, as well as the 2014 News and Documentary Emmy award for Outstanding Nature Programming. The film has screened in more than 172 countries and on all 7 continents.

As a kind of companion piece to his documentary project, Balog published the book, ICE: Portraits of Vanishing Glaciers, in 2012. A review from Book News says, “Photographs…strike the eye with such power, and appeal with such subtlety, that viewers could scarcely imagine such epic materials and landscapes could disappear. General readers, artists, nature or geology fans, people who live or play in winter landscapes, and photographers, regardless of scientific or political bent, will all value this book.”

Balog is also the founder of the Earth Vision Institute (EVT), a non-profit organization dedicated to creating, publishing, and sharing “visual voices” to educate people about the impacts of climate change. (It was initially named the Earth Vision Trust, but Balog changed the name on January 1, 2015.) The Institute’s most recent project was “Getting The Picture: Our Changing Climate,” an innovative online multimedia tool for climate education, which synchronized art, science, and adventure. People of all ages can take advantage of this free interactive educational tool to gain a fresh perspective on the changing climate.

Please follow, share and like us:
error