Earthquake-driven erosion rates under hyper-arid condition in the Atacama Desert, Chile
Abstract
The central Atacama Desert in Northern Chile is one of the driest regions on Earth and therefore is subject to little or no fluvial influence capable of transporting larger blocks or boulders. Although little is known about erosion and transport rates in such hyper-arid areas they are thought to be very low. In the Atacama Desert, erosion is largely governed by aeolian abrasion and thermal expansion. Recent studies show that earthquake driven erosion, such as abrasion at boulder contacts, has to be taken into account for reconstructing erosion rates in desert like environments. The rates of this mechanically driven rubbing-erosion are yet to be determined and their contribution to the total amount of erosion remains unclear. The studied boulders in the Atacama Desert are intensely covered by desert varnish with the exception of surfaces that have experienced erosion through rubbing. Preliminary results show that rubbing-erosion is high enough for calculating an erosion rate for these boulders. On the basis of desert varnish formation rates and the extent of polished surfaces on the studied boulders, we can estimate the rate of boulder-rubbing erosion. In turn, a better understanding of the relationships between earthquake-driven boulder erosion and the frequency of earthquakes could be a useful tool in paleoseismology. Although rare on Earth, hyper-aridity dominates today's surface on Mars and hence, quantifying erosional rates under such conditions will be key for understanding the Martian geomorphology.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMEP53C0973R
- Keywords:
-
- 1824 Geomorphology: general;
- HYDROLOGYDE: 1825 Geomorphology: fluvial;
- HYDROLOGYDE: 1826 Geomorphology: hillslope;
- HYDROLOGYDE: 1886 Weathering;
- HYDROLOGY