Major hydrological regime change along the semiarid western coast of South America - Response to comments by Maldonado and Moreiras [page number in this issue]

摘要

Based on the sedimentology, geomorphology and geochronology of eolian and alluvial deposits at Quebrada Santa Julia (QSJ, 31°50'S) site, in a small coastal watershed in the semiarid central Chile, Ortega et al. (2012) interpreted a regional arid climate setting concomitantly with high local humidity due to reinforced coastal fog development be-tween 13,000 and 8600 cal yr BP. Together with other continental proxies and paleo-SST records off central Chile, Ortega et al. (2012) proposed La Ni?a-like conditions during the latest Pleistocene-early Holocene along this semiarid coast. A major hydrologic regime shift shortly after 8600 cal yr BP resulted in higher frequency of torrential rainfall episodes still under an arid climate setting, before the onset of El Ni?o at-5500 cal yr BP (e.g., Rodbell et al., 1999). This hypothesis differs from that of Maldonado and Moreiras (2013) based on pollen records, who suggest humid conditions associated with precipitation around 13,000 and 10,500 cal yr BP (e.g., Maldonado et al., 2010).