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Record Search Query:
Collaborative Proposal: Decades-long Experiment on Wind-Driven Rock Abrasion in the Ice-Free Valleys, Antarctica
Entry ID: USAP-1341712

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Summary
Abstract:

Many of the natural processes that modify the landscape inhabited by humans occur over very long timescales, making them difficult to observe. Exceptions include rare catastrophic events such as earthquakes, volcanic eruptions, and floods that occur on short timescales. Many significant processes that affect the land and landscape that we inhabit operate on time scales imperceptible to humans. ...


Technical Description of Project:


The goal of this project is to study the role of wind abrasion by entrained particles in the evolution of the McMurdo Dry Valleys in the Transantarctic Mountains. During the 1983 to 1984 field seasons, over 5000 rock targets were installed at five heights facing the 4 cardinal directions at 10 locations (with an additional site containing fewer targets) to study rates of physical weathering due primarily to eolian abrasion. In addition, rock cubes and cylinders were deployed at each site to examine effects of chemical weathering. The initial examination of sam ples returned after 1, 5, and 10 years of exposure, showed average contemporary abrasion rates consistent with those determined by cosmogenic isotope studies, but further stress that average should not be interpreted as meaning uniform. The samples will be characterized using mass measurements wtih 0.01 mg precision balances, digital microphotography to compare the evolution of their surface features and textures, SEM imaging to examine the micro textures of abraded rock surfaces, and optical microscopy of thin sections of a few samples to examine the consequences of particle impacts extending below the abraded surfaces. As much as 60-80% of the abrasion measured in samples from 1984-1994 appears to have occurred during a few brief hours in 1984. This is consistent with theoretical models that suggest abrasion scales as the 5th power of wind velocity. The field work will allow return of multiple samples after three decades of exposure, which will provide a statistical sampling (beyond what is acquired by studying a single sample), and will yield the mass loss data in light of complementary environmental and sand kinetic energy flux data from other sources (e.g. LTER meteorology stations). This study promises to improve insights into one of the principal active geomorphic process in the Dry Valleys, an important cold desert environment, and the solid empirical database will provide general constraints on eolian abrasion under natural conditions.


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Description: NSF Award Abstract.

Description: Long-term rock abrasion study in the Dry Valleys
Data Set Citation
Version: Not provided
Temporal Coverage
Start Date: 2014-12-15T00:00:00.000Z
Stop Date: 2017-11-30T23:59:59.999Z
ISO Topic Category
Data Set Progress
COMPLETE
Data Center
United States Antarctic Program Data Center
Data Center URL: http://www.usap-dc.org/

Data Center Personnel
Name: Data Manager
Email: info at usap-dc.org
Contact Address:
Lamont-Doherty Earth Observatory
61 Route 9W
City: Palisades
Province or State: NY
Postal Code: 10964
Country: USA
Personnel
Bernard Hallet
Role: INVESTIGATOR
Email: hallet at u.washington.edu
Contact Address:
University of Washington
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Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 1970-01-01
Last DIF Revision Date: 2017-10-13