Shifting Wind Vectors As Evidenced By Yardang Morphology And The Implications For Climate Change In Qaidam Basin, China

Abstract

Climate change affects wind patterns, and in landscapes where wind-eroded features exist, these changes can be observed in landform geomorphology. Landforms such as sand dunes (modern) and yardangs (∼1000s years) show evidence for the direction of the winds that shaped them. This study creates and analyzes a database of wind-shaped landforms in Qaidam Basin, China, to determine if climate change has caused changes in wind patterns. The basin shows evidence of extensive erosion by unidirectional winds carrying abrasive particles, but the strong, regular dust storms required have not been observed in the past 50 years. Global climate models predict that the region experienced stronger winds during glacial periods, the last of which occurred about 20,000 years ago. This study aims to test and to possibly fine-tune this model. Sand dune morphology is used to represent current and/or recent wind patterns, and yardang directionality is used to represent past wind patterns. Landform vectors are measured in Google Earth and then modeled using ArcGIS spatial analysis tools. The resulting model shows distinct areas of the basin where these two datasets do not correspond with one another. It is possible that these regions are evidence for a past wind regime and therefore a past climate change. These results suggest that in addition to the modern SE-directed winds, the basin at one time experienced strong and sustained SW-directed winds.

AAPG Datapages/Search and Discovery Article #90215 © 2015 Pacific Section AAPG Convention, Oxnard, California, May 3-6, 2015