Nav: Home

Tidewater glaciers: Melting underwater far faster than previously estimated?

July 25, 2019

A tidewater glacier in Alaska is melting underwater at rates upwards of two orders of magnitude greater than what is currently estimated, sonar surveys reveal. The study's results, based on direct measurements, suggest that some glaciers may be in "hotter water" than previously thought. Like vast frozen rivers, tidewater glaciers flow from the land and into the sea, forming a partially submerged ice-ocean boundary. However, unlike terrestrial glaciers, which are often sequestered to high-altitudes, tidewater glaciers can be far more dynamic and subject to ongoing changes driven by underwater melting and iceberg calving where the ocean meets the ice. While it is widely recognized that ice loss from these glaciers influences both the rate of sea level rise and potentially global ocean circulation - a primary driver of global climate - the understanding of the dynamics of tidewater glacier melt, particularly as a response to accelerated warming in high-latitude glacier environments, is largely predicated upon sparse data, indirect inferences and an unconstrained theoretical model of subsurface melting. To date, suggest the authors of this study, no direct measurements of submarine melting at tidewater glacier fronts have been made. To address this lack of direct observations, David Sutherland and colleagues conducted repeat multibeam sonar surveys of the submerged face of the LeConte Glacier in Southeast Alaska. Along with other ocean, ice and atmospheric measurements collected in August 2016 and May 2017, the sonar images were used to document and create a time-variable, three-dimensional record of changes in the glacier face that could be linked to melting and calving patterns. Sutherland et al. discovered seasonally increasing submarine melt across the glacier face and at rates far greater than theory-based predictions. Their results, they say, suggest a pressing need to reevaluate existing models of tidewater glacier ice loss.
-end-


American Association for the Advancement of Science

Related Glaciers Articles:

Drones help map Iceland's disappearing glaciers
Dr. Kieran Baxter from the University of Dundee has created composite images that compare views from 1980s aerial surveys to modern-day photos captured with the help of state-of-the-art technology.
Disappearing Peruvian glaciers
It is common knowledge that glaciers are melting in most areas across the globe.
New insight into glaciers regulating global silicon cycling
A new review of silicon cycling in glacial environments, led by scientists from the University of Bristol, highlights the potential importance of glaciers in exporting silicon to downstream ecosystems.
Tidewater glaciers: Melting underwater far faster than previously estimated?
A tidewater glacier in Alaska is melting underwater at rates upwards of two orders of magnitude greater than what is currently estimated, sonar surveys reveal.
Asia's glaciers provide buffer against drought
A new study to assess the contribution that Asia's high mountain glaciers make to relieving water stress in the region is published this week (May 29, 2019) in the journal Nature.
Melting small glaciers could add 10 inches to sea levels
A new review of glacier research data paints a picture of a future planet with a lot less ice and a lot more water.
Using satellites to measure rates of ice mass loss in glaciers
Researchers from Friedrich-Alexander-Universität Erlangen-Nürnberg have now investigated all glacial areas in South America in more detail than ever before, from the tropical areas to the subpolar regions.
Volcanoes and glaciers combine as powerful methane producers
Large amounts of the potent greenhouse gas methane are being released from an Icelandic glacier, scientists have discovered.
How much debris is lying on glaciers?
A study by scientist Dirk Scherler of the German Research Centre for Geosciences GFZ and two colleagues from Switzerland shows a possibility to detect the extent of debris on mountain glaciers globally and automatically via satellite monitoring.
Investigating glaciers in depth
Global sea level is rising constantly. One factor contributing to this rise is the melting of the glaciers.
More Glaciers News and Glaciers Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#544 Prosperity Without Growth
The societies we live in are organised around growth, objects, and driving forward a constantly expanding economy as benchmarks of success and prosperity. But this growing consumption at all costs is at odds with our understanding of what our planet can support. How do we lower the environmental impact of economic activity? How do we redefine success and prosperity separate from GDP, which politicians and governments have focused on for decades? We speak with ecological economist Tim Jackson, Professor of Sustainable Development at the University of Surrey, Director of the Centre for the Understanding of Sustainable Propserity, and author of...
Now Playing: Radiolab

An Announcement from Radiolab