Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Thawing Permafrost: The speed of coastal erosion in Eastern Siberia has nearly doubled

29.10.2013
The high cliffs of Eastern Siberia – which mainly consist of permafrost – continue to erode at an ever quickening pace. This is the conclusion which scientists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research have reached after their evaluation of data and aerial photographs of the coastal regions for the last 40 years.

According to the researchers, the reasons for this increasing erosion are rising summer temperatures in the Russian permafrost regions as well the retreat of the Arctic sea ice. This coastal protection recedes more and more on an annual basis.


Shrinking island
© F. Günther / Alfred Wegener Institute

As a result, waves undermine the shores. At the same time, the land surface begins to sink. The small island of Muostakh east of the Lena Delta is especially affected by these changes. Experts fear that it might even disappear altogether should the loss of land continue.

The interconnectedness is clear and unambiguous: The warmer the east Siberian permafrost regions become, the quicker the coast erodes. “If the average temperature rises by 1 degree Celsius in the summer, erosion accelerates by 1.2 meters annually,“ says AWI geographer Frank Günther, who investigates the causes of the coastal breakdown in Eastern Siberia together with German and Russian colleagues, and who has published his findings in two scientific articles.

In these studies, he and his team evaluated high-resolution air and satellite photos from 1951 to 2012 as well as measurements of the past four years. In addition, the researchers surveyed four coastal sections along the Laptev Sea (see map) and on the island of Muostakh.

One example of the changes documented in their research are the warming summers. While the temperatures during the period of investigation exceeded zero degrees Celsius on an average of 110 days per year, the scientists counted a total of 127 days in the years 2010 and 2011. The following year, 2012, the number of days with temperatures above freezing increased to 134.

This increase in temperature is not without consequences. Whereas a thick layer of sea ice used to protect the frozen soil almost all year round, it now recedes in this part of the Arctic for increasing periods of time during the summer months. The number of summer days on which the sea ice in the southern Laptev Sea vanishes completely grows steadily. “During the past two decades, there were, on average, fewer than 80 ice-free days in this region per year. During the past three years, however, we counted 96 ice-free days on average. Thus, the waves can nibble at the permafrost coasts for approximately two more weeks each year,“ explains AWI permafrost researcher Paul Overduin.

The waves dig deep recesses into the base of the high coasts. The result: The undermined slopes break off bit by bit. During the past 40 years, the coastal areas surveyed retreated on average 2.2 meters per year. “During the past four years, this value has increased at least 1.6 times, in certain instances up to 2.4 times to reach 5.3 meters per year,“ says Paul Overduin.

For the little island of Muostakh east of the harbour town of Tiksi, this may well mean extinction. “In fewer than one hundred years, the island will break up into several sections, and then it will disappear quickly,“ predicts Frank Günther. On its northern tip, the island shows fluctuating annual erosion rates between 10 and 20 meters per year, and it has already lost 24 per cent of its area in the past 60 years. Because the subsurface here consists of more than 80 per cent of ice that has formed within the soil, and since the ice is gradually melting, the island’s surface collapses as well. The scientists speak of a 34 per cent loss in volume. “If one bears in mind that it took tens of thousands of years for the island to form through sedimentary deposition, then its disintegration is proceeding at a very rapid pace,“ says Paul Overduin.

In addition, long-term studies conducted by AWI scientists show the impact of coastal erosion for the sea as well. Depending on the kind of erosion and the particular structure of the coast, between 88 and 800 tons of plant-, animal, and microorganism-based carbon are currently washed into the sea per year and kilometre of coastline – these are materials that had been sealed in the permafrost thus far. With regard to the Laptev Sea, this translates into approximately one eighth of the organic carbon that is transported by the Lena River annually – and the Lena is a river that encompasses a drainage basin the size of the Mediterranean. “We can, however, assume larger quantities if this accelerating coastal erosion we currently observe continues,“ the scientists write in their subject-specific paper for the Biogeosciences special volume: “Interactions between the land and sea in the Lena Delta Region.“ Once in the water, carbon may turn into carbon dioxide and, as a result, contribute to the acidification of the oceans: the composition of our oceans becomes less alkaline.

These studies were conducted as part of the PROGRESS project which is funded by the Federal Ministry of Education and Research. PROGRESS is the acronym for Potsdamer Forschungs- und Technologieverbund für Naturgefahren, Klimawandel und Nachhaltigkeit (Potsdam Research Cluster for Georisk Analysis, Environmental Change and Sustainability). In addition to the Alfred Wegener Institute, sectors of the Deutsches GeoForschungsZentrum (German Geo Research Center), the Potsdam-Institut für Klimafolgenforschung (Potsdam Institute for the Study of Climate Change), as well as the Hasso-Plattner-Institut für Softwaresystemtechnik (Hasso Plattner Institute for Software System Technology) are participating in this project. For more information on PROGRESS, please visit the project website http://www.earth-in-progress.de.

Notes for Editors

Printable photos and maps are available in the online version of this press release: http://www.awi.de/en/news/press_releases/

The two studies have been published under following titles:
• F. Günther, P. P. Overduin, A. V. Sandakov, G. Grosse and M. N. Grigoriev: Short- and long-term thermo-erosion of ice-rich permafrost coasts in the Laptev Sea region Biogeosciences, 10, 4297–4318, 2013, doi:10.5194/bg-10-4297-2013 (Link to the paper: http://epic.awi.de/33391/) (Link to the special edition „Interactions between the land and sea in the Lena Delta Region“: http://www.biogeosciences.net/special_issue122.html)

• F. Günther, P. P. Overduin, A. Baranskaya, T. Opel and M. N. Grigoriev: Observing Muostakh Island disappear: erosion of a ground-ice-rich coast in response to summer warming and sea ice reduction on the East Siberian shelf, The Cryosphere Discuss., 7, 4101–4176, 2013, doi:10.5194/tcd-7-4101-2013 (Link to the paper: http://www.the-cryosphere-discuss.net/7/4101/2013/tcd-7-4101-2013.html)

Your scientific contact partners at the Alfred Wegener Institute are:
• Frank Günther (Tel.: +49-(0)331-288-2156 ; E-Mail: Frank.Guenther(at)awi.de and
• Dr. Paul Overduin, (Tel.: +49-(0)331-288-2113; E-Mail: Paul.Overduin(at)awi.de).

Your contact person in the Department of Communications and Media Relations is Kerstin Holzheimer, (Tel.: +49 471 4831-1376, e-mail: medien(at)awi.de).

Follow the Alfred Wegener Institute on Twitter (https://twitter.com/AWI_Media) and Facebook (http://www.facebook.com/AlfredWegenerInstitute) for all current news and information on everyday stories from the life of the Institute.

The Alfred Wegener Institute conducts research in the Arctic and Antarctic and in the high and mid-latitude oceans. The Institute coordinates German polar research and provides important infrastructure such as the research icebreaker Polarstern and stations in the Arctic and Antarctic to the international scientific world. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.

Ralf Röchert | idw
Further information:
http://www.awi.de

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>