Low-altitude permafrost research in an overcooled talus slope–rock glacier system in the Romanian Carpathians (Detunata Goală, Apuseni Mountains)

Low-altitude permafrost research in an overcooled talus slope–rock glacier system in the... Ground and air temperature monitoring, geophysical soundings and dendrological investigations were applied to a basaltic talus slope–rock glacier system from Detunata site in the Apuseni Mountains (Western Romanian Carpathians) to verify the presence of sporadic permafrost at 1020–1110masl, well below the regional limit of mountain permafrost. The near 0°C mean annual ground surface temperatures imposed by the large negative annual thermal anomalies of the ground (up to 7.4°C), together with the high resistivity values and the occurrence of trees with severe growth anomalies, support the presence of permafrost at this location. Temperature measurements and ground air circulation experiments proved that the so-called “chimney effect” is the main process favoring the ground overcooling and allowed for the construction of a model of ground air circulation in complex morphology deposits. The texture and porosity of the debris were quantified along with the local morphology in order to evaluate their role upon the chimney circulation. The debris porosity was found to be very high promoting intense ground overcooling during the cold season, including the periods of high snow cover due to the development of snow funnels. It efficiently reduces the heat transfer during summer thus contributing essentially to permafrost preservation. In compound morphologies, the depressed and low-lying features are the cold zones subjected to winter overcooling and summer chill, while the high-positioned and convex-up landforms become warm air evacuation features with positive thermal anomalies. Tree-ring measurements showed that the growth of cold-affected trees is higher during colder intervals (years to decades) probably as a consequence of the weakened katabatic air outflow during cooler summers. The dendrological analysis of multi-centennial spruces and their growth rates also provided palaeoclimatic inferences for the last 200years. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Geomorphology Elsevier

Low-altitude permafrost research in an overcooled talus slope–rock glacier system in the Romanian Carpathians (Detunata Goală, Apuseni Mountains)

Loading next page...
 
/lp/elsevier/low-altitude-permafrost-research-in-an-overcooled-talus-slope-rock-QDTu2FQLZA
Publisher
Elsevier
Copyright
Copyright © 2017 Elsevier B.V.
ISSN
0169-555X
eISSN
1872-695X
D.O.I.
10.1016/j.geomorph.2017.07.029
Publisher site
See Article on Publisher Site

Abstract

Ground and air temperature monitoring, geophysical soundings and dendrological investigations were applied to a basaltic talus slope–rock glacier system from Detunata site in the Apuseni Mountains (Western Romanian Carpathians) to verify the presence of sporadic permafrost at 1020–1110masl, well below the regional limit of mountain permafrost. The near 0°C mean annual ground surface temperatures imposed by the large negative annual thermal anomalies of the ground (up to 7.4°C), together with the high resistivity values and the occurrence of trees with severe growth anomalies, support the presence of permafrost at this location. Temperature measurements and ground air circulation experiments proved that the so-called “chimney effect” is the main process favoring the ground overcooling and allowed for the construction of a model of ground air circulation in complex morphology deposits. The texture and porosity of the debris were quantified along with the local morphology in order to evaluate their role upon the chimney circulation. The debris porosity was found to be very high promoting intense ground overcooling during the cold season, including the periods of high snow cover due to the development of snow funnels. It efficiently reduces the heat transfer during summer thus contributing essentially to permafrost preservation. In compound morphologies, the depressed and low-lying features are the cold zones subjected to winter overcooling and summer chill, while the high-positioned and convex-up landforms become warm air evacuation features with positive thermal anomalies. Tree-ring measurements showed that the growth of cold-affected trees is higher during colder intervals (years to decades) probably as a consequence of the weakened katabatic air outflow during cooler summers. The dendrological analysis of multi-centennial spruces and their growth rates also provided palaeoclimatic inferences for the last 200years.

Journal

GeomorphologyElsevier

Published: Oct 15, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off