Evolution of Storm Surges over the Little Ice Age Indicated by Aeolian Sand Records on the Coast of the Beibu Gulf, China

Abstract

The Wutou section, hereinafter referred to as “WTS”, lies in Jiangping, Guangxi Province, China (21°32′8.25″ N, 108°06′59.9″ E; thickness of 246 cm) and consists of fluvial-lacustrine facies and dune sands of the Late Holocene. This study reconstructed the evolution of storm surges along the coast of the Beibu Gulf, Guangxi over the Little Ice Age, based on three accelerator mass spectrometry (AMS)-14C, optically stimulated luminescence (OSL) dating ages, and the analyses of grain size and heavy minerals. The analysis results indicated that the storm sediments interspersed among aeolian sands, lagoon facies, and weak soil display a coarse mean grain size and poor sorting. The storm sediments also show high maturity of heavy minerals and low stability resulting from rapid accumulation due to storm surges originating from the land-facing side of the coastal dunes. Records of seven peak storm surge periods were recorded in the WTS over the past millennium and mainly occurred after 1400 AD, i.e., during the Little Ice Age. The peaks in storm surges, including the 14Paleostrom deposit (hereinafter referred to as “Pd”) (1425–1470AD), 10Pd (1655–1690AD), 6Pd (1790–1820AD), and 4Pd (1850–1885AD) approximately corresponded with the periods of minimum sunspot activity, suggesting that the periods of storm surge peaks revealed by the WTS were probably regulated to a great extent by solar activity.

Keywords

• coastal aeolian sands
• Beibu Gulf in Guangxi
• over the Little Ice Age
• storm surge
• grain size