Mega-blowouts in Qinghai–Tibet Plateau

EARTH SURFACE PROCESSES AND LANDFORMS    DOI: 10.1002/esp.4507

Wanyin Luo  Zhongyuan Wang  Junfeng Lu  Linghai Yang  Guangqiang Qian  Zhibao Dong  Mark D. Bateman

Abstract

Blowouts are wind‐eroded landforms that are widely distributed in the north‐eastern part in Qinghai–Tibet Plateau (QTP), China. These blowouts are thought to form in response to climate change and/or human activity but little is known about their morphodynamics. Using field surveys, remote sensing and geographic information system (GIS) spatial analysis, the distribution and morphology of blowouts are analysed and their initiation considered. Results show the QTP mega‐blowouts are some of the largest in the world. The orientations of the trough shaped blowouts are parallel with the prevailing wind, but the saucer and bowl‐shaped blowouts are influenced by bi‐directional transport. Whilst regional patterns of blowout shape and size were observed to reflect the extent of aeolian sediments and wind regimes, the relationship between the different morphological parameters showed consistency. During initial stages of development, the length to width ratios of blowouts increase rapidly with area but after they reach a mega size this relationship stabilizes as blowouts widen. Initial luminescence dating shows that blowouts appear to have initiated ~100 to 500 years ago, coinciding with the Little Ice Age (LIA) climate event when northwest winds are known to have intensified. Further work is required to confirm this initiation period and establish the significance of mega blowouts for landscape degradation and human activities. © 2018 John Wiley & Sons, Ltd.

文章链接：https://onlinelibrary.wiley.com/doi/full/10.1002/esp.4507