Preliminary evidence for a 1000-year-old tsunami in the South China Sea

Abstract

The risk of large, devastating tsunamis in the South China Sea and its surrounding coastal region is commonly underestimated or unrecognized due to the difficulty of differentiating tsunami from storm deposits. As a consequence, few convincing records have documented tsunami deposits in this region. Here we report preliminary evidence from Xisha Islands in the South China Sea for a large tsunami around AD 1024. Sand layers in lake sediment cores and their geochemical characteristics indicate a sudden deposition event around AD 1024, temporally consistent with a written record of a disastrous event characterized by high waves in AD 1076. Heavy coral and shell fossils, which are older than AD 1024, deposited more than 200 meters into the island, further support the occurrence of a high-energy event such as a tsunami or an unusually large storm. Our results underscore the importance of acknowledging and understanding the tsunami hazard in this area.

Occurrence of 1 ka-old corals on an uplifted reef terrace in west Luzon, Philippines: Implications for a prehistoric extreme wave event in the South China Sea region

“…From transported coral blocks and lagoon sediments in the southern SCS (Yongshu Reef ), Yu et al (2009) inferred a past strong storm or tsunami in AD 1064. Sand layers in lake sediment cores from the Xisha islands also indicate a sudden and high-energy event, potentially a tsunami, in AD 1024 (Sun et al 2013). Among the historical strong wave events recorded in the SCS region, the AD 1071 event which affected Guangdong, China closely correlates with the stratigraphic data of Yu et al (2009), Sun et al (2013), and our dated coral samples (e.g., 945.1 ± 4.6 years BP or AD 1043-1051; 903.1 ± 3.9 years BP or AD 1000-1010) in Badoc Island.…”

“…Sand layers in lake sediment cores from the Xisha islands also indicate a sudden and high-energy event, potentially a tsunami, in AD 1024 (Sun et al 2013). Among the historical strong wave events recorded in the SCS region, the AD 1071 event which affected Guangdong, China closely correlates with the stratigraphic data of Yu et al (2009), Sun et al (2013), and our dated coral samples (e.g., 945.1 ± 4.6 years BP or AD 1043-1051; 903.1 ± 3.9 years BP or AD 1000-1010) in Badoc Island. A potentially large coseismic uplift event in the last millennium is also inferred along west Luzon based on uplifted coral microatolls in La Union.…”

Last Millennium Adélie Penguin Mortality and Colony Abandonment Events on Long Peninsula, East Antarctica

“…Although both profiles have a relatively slow and uniform accumulation rate in their lower parts, deposition increased greatly at ~750 years BP, resulting in phases of rapid deposition of ~20 cm within no more than a few decades. Unlike rapid coarse‐grained inorganic sediment deposition formed by glacier movements or sea level transgression (Leonard, ; Sun, Zhou, et al, ), the sediments corresponding to the phases of rapid deposition in LP1 and LP2 are highly organic. They have extremely high contents of the bio‐element P, indicating the impact of penguin‐derived inputs from the surrounding subcolonies (Figure ).…”

Seabed erosion and deposition related to the typhoon activity of the past millennium on the southeast coast of China

“…() was adopted by Sun et al . () when they interpreted the flood event found from the Xisha Islands. However, according to the official history of the Song Dynasty (The Book of Song, chapters Wuxingzhi) and the local gazettes of Chaoyang and Haiyang counties, the flood event of ad 1076 was actually caused by a super‐typhoon, in the 10th lunar month (approximately November).…”