A high resolution absolute dating holocene and deglacial asian

Posted by / 23-Jul-2020 06:24

A high resolution absolute dating holocene and deglacial asian

The results provide robust evidence for oceanic and terrestrial environmental changes in East Asia during the past 40 ka.

Here, we present three sets of independent climate proxy data from a single core (DG9603) from the Okinawa Trough, East China Sea (ECS): one of terrestrial origin (pollen) and two of marine origin [foraminifera (17, 18) and alkenone paleothermometry (U) (19, 20)].

Sea surface temperatures in the Okinawa Trough were influenced mainly by heat transport from the tropical western Pacific Ocean by the Kuroshio Current, but the epicontinental vegetation of the ECS was influenced by atmospheric circulation linked to the northern high-latitude climate. The Okinawa Trough, close to the ECS shelf edge, has a water depth of more than 2,700 m in places and was continuously submerged during the glacial/interglacial cycles; thus, it continuously accumulated deposits of mixed terrestrial and marine sources.

Asynchronous terrestrial and marine signals of the last deglacial warming in East Asia were thus clearly related to ocean currents and atmospheric circulation. Core DG9603 was taken from the mid-Okinawa Trough (28°08.869′N, 127°16.238′E, water depth of 1,100 m) (C ages were converted to calendar ages using software CALIB 6.1 (26) and Marine09 datasets (27).

Sea surface temperatures in the Okinawa Trough were influenced mainly by heat transport from the tropical western Pacific Ocean by the Kuroshio Current, but the epicontinental vegetation of the ECS was influenced by atmospheric circulation linked to the northern high-latitude climate.

However, sea surface temperature estimates from foraminifera and alkenone paleothermometry increased around 20–19 ka BP, as in the Western Pacific Warm Pool (WPWP).

Previous research has focused on determining the relative timing of climate change during the last deglaciation between terrestrial and marine regions and/or between low- and high-latitude regions, with different conclusions: However, the vast majority of these results were acquired through comparisons of different proxy records from different materials with different resolution and dating uncertainties.

We argue that (i) early warming seawater of the WPWP, driven by low-latitude insolation and trade winds, moved northward via the Kuroshio Current and triggered marine warming along the ECS around 20-19 ka BP similar to that in the WPWP, and (ii) an almost complete shutdown of the Atlantic Meridional Overturning Circulation ca. The ages of samples from bottom to top were estimated by linear interpolation of these age control points.

18-15 ka BP was associated with cold Heinrich stadial-1 and delayed terrestrial warming during the last deglacial warming until ca. The top 4.5 m covers the past 42 ka, with an average resolution of Overview maps of the Antarctic Ocean, Pacific Ocean, and Arctic Ocean, as well as the adjacent East Asia, showing locations of core DG9603 and selected paleoclimate sites in relation to oceanographic features.

The marine system in this region mainly consists of the Kuroshio Current (21, 22), which flows north on the western side of the North Pacific Ocean, analogous to the Gulf Stream in the North Atlantic Ocean.

It thus provides direct and unambiguous evidence of the links between marine and terrestrial environments (21, 22).

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Located in the eastern part of the ECS between the Pacific Ocean and the Eurasian continent, the Okinawa Trough is the only area that has continuously recorded environmental changes of both oceans and adjacent landmasses simultaneously.

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