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Published September 15, 2009 | public
Journal Article

High-frequency rock temperature data from hyper-arid desert environments in the Atacama and the Antarctic Dry Valleys and implications for rock weathering

Abstract

In desert environments with low water and salt contents, rapid thermal variations may be an important source of rock weathering. We have obtained temperature measurements of the surface of rocks in hyper-arid hot and cold desert environments at a rate of 1/s over several days. The values of temperature change over 1-second intervals were similar in hot and cold deserts despite a 30 °C difference in absolute rock surface temperature. The average percentage of the time dT/dt > 2 °C/min was ~ 8 ± 3%, > 4 °C/min was 1 ± 0.9%, and > 8 °C/min was 0.02 ± 0.03%. The maximum change over a 1-second interval was ~ 10 °C/min. When sampled to simulate data taken over intervals longer than 1 s, we found a reduction in time spent above the 2 °C/min temperature gradient threshold. For 1-minute samples, the time spent above any given threshold was about two orders of magnitude lower than the corresponding value for 1-second sampling. We suggest that a rough measure of efficacy of weathering as a function of frequency is the product of the percentage of time spent above a given threshold value multiplied by the damping depth for the corresponding frequency. This product has a broad maximum for periods between 3 and 10 s.

Additional Information

Copyright © 2009 Elsevier. Received 23 January 2009; revised 3 April 2009; accepted 7 April 2009. Available online 16 April 2009. This work was supported by funding from NASA ASTEP and IPY programs. We thank the members of the field teams for help in all aspects of the fieldwork. The air temperature data from the Antarctic sites as obtained form the McMurdo LTER database. We thank the reviewers for comments that improved the paper. Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.geomorph.2009.04.005.

Additional details

Created:
August 21, 2023
Modified:
October 19, 2023