Intense debate persists about the timing and magnitude of the wet phases in the East Asia deserts since the late Pleistocene. Here we show reconstructions of the paleohydrology of the East Gobi Desert since the last interglacial using satellite images and digital elevation models (DEM) combined with detailed section analyses. Paleolakes with a total area of 15,500 km2during Marine Isotope Stage 5 (MIS 5) were identified. This expanded lake system was likely coupled to an 800–1000 km northward expansion of the humid region in East China, associated with much warmer winters. Humid climate across the Gobi Desert during MIS 5 likely resulted in a dustier MIS 4 over East Asia and the North Pacific. A second wet period characterized by an expanded, albeit smaller, lake area is dated to the mid-Holocene. Our results suggest that the East Asian Summer Monsoon (EASM) might have been much weaker during MIS 3.
2 June 2023 in Geostandards and Geoanalytical Research
The impact of rapid climate change on civilizations is of global concern. The Western Zhou (1045–771 BC) was ancient China’s third dynasty and one of the most powerful empires of its time. After a 274-year reign, the dynasty collapsed, accompanied by significant population migration. Various factors have been proposed to explain its fall, while the role of climate change has been largely ignored. Here we present well-dated, high-resolution stalagmite records from Northeast and Southeast China, along with other paleoclimatic and archaeological evidence, to demonstrate the critical role of the 2.8 ka climatic event in the dynasty’s collapse and subsequent migration. Our results indicate a “north dry–south wet” dipolar pattern in the Chinese monsoon region during this event. The drought and cold severely affected the Western Zhou core areas and exacerbated invasions by northern nomads, contributing to its collapse. The resulting environmental stresses and conflicts likely triggered substantial southward migration.
The Tibetan Plateau is known as the core area of the third pole of the Earth and is a key area for global climate change research. This study uses the Zabuye Salt Lake travertine dam as the research object and U–Th dating as the chronological framework and proposes that the carbon and oxygen isotopes of travertine can be used as a precipitation index through the analysis of hydrogen and oxygen isotopes of spring water, and petrology, mineralogy, carbon and oxygen isotopes of travertine. The precipitation records of Zabuye Salt Lake over the last 800 years show a dry condition in 1191–1374 AD (Medieval Warm Period), a humid condition in 1374–1884 AD (Little Ice Age), and a dry condition in 1884–1982 AD (Current Warn Period), indicating a warm–dry/cold–moist climate pattern, which is consistent with precipitation records from many places on the Tibetan Plateau. We preliminarily point out that travertine can record the evolution of paleoprecipitation (paleomonsoon) at least on the decadal–centennial scale. The Indian summer monsoon has been the main factor influencing precipitation change in Zabuye Salt Lake over the past 800 years, and the change in evapotranspiration intensity caused by temperature change driven by solar radiation is also an important factor affecting dry–moist change.