Petromagnetic parameters of bottom sediments as indicators of the climatic and environmental changes in the central zone of the Sea of Okhotsk during the last 350 kyr

Abstract

Bottom sediments from the central zone of the Sea of Okhotsk were preliminarily dated. The petromagnetic parameters of two groups of samples formed at cold and warm climatic stages were studied. Warm oxygen isotopic stages and substages were characterized by the coexistence of pseudo-single-domain allogenic magnetite and predominant magnetite and greigite (pyrrhotite) grains subject to biologic control. At cold stages, sediments containing a mixture of pseudo-single-domain and multidomain terrigenous magnetite particles accumulated. The petromagnetic curves agree with the normalized standard oxygen isotopic curve over the last 350 kyr of the column section.

Centennial to millennial climate variability in the far northwestern Pacific (off Kamchatka) and its linkage to the East Asian monsoon and North Atlantic from the Last Glacial Maximum to the early Holocene

“…core SO-201-12KL (hereinafter 12KL) (Max et al, 2012(Max et al, , 2014. Using robust age controls, we establish a tight linkage between the centennial events with higher productivity in the NW Pacific and the sub-interstadial strengthened East Asian summer monsoon (EASM) expressed in cave stalagmite δ 18 O records.…”

“…These model and proxy studies suggested either in-phase relationships of deglacial variability between the North (N) Atlantic and NW Pacific (Caissie et al, 2010;Chikamoto et al, 2012;Kienast and McKay, 2001;Seki et al, 2002) or out-of-phase responses (Gebhardt et al, 2008;Sarnthein et al, 2006). The in-phase relationship has been attributed to rapid atmospheric teleconnections in the Northern Hemisphere on a decadal timescale (Max et al, 2012). The winter Arctic Oscillation (AO), which resembles the North Atlantic Oscillation, directly influences the surface air temperature and sea level pressure over the region northwards of 35 • N in East Asia (Sung et al, 2006).…”

“…Recent studies on high-resolution and well-dated sediment cores from the subarctic NW Pacific, the Okhotsk Sea, and the western Bering Sea show the variations in SST during the last deglaciation similar to the NE Pacific and to the N Atlantic and Greenland temperature variability (Caissie et al, 2010;Max et al, 2012;Seki et al, 2002). These studies suggest a close linkage to deglacial variations in AMOC associated with rapid atmospheric teleconnection, which were responsible for a quasi-synchronous SST pattern between the N Atlantic and N Pacific during the last deglaciation.…”

“…An age model of core 41-2 was constructed using accelerator mass spectrometry (AMS) 14 C dating and by correlating the productivity events and relative paleomagnetic intensity (RPI) variability with those of the well-dated nearby Figure 1. Bathymetry, surface water currents and location of the cores 41-2 (star) and 12KL (cross) (Max et al, 2012) in the N Pacific. Surface currents as in Favorite et al (1976) with modifications.…”

Sediment provenance variations in the southern Okhotsk Sea over the last 180 ka: Evidence from light and heavy minerals

“…In general, the IRD carried by the terrigenous fraction is an assorted mixture of gravel, sand, silt and clay size materials (Gorbarenko et al, 2002). However, the defined clastic diameter of terrigenous materials considered as IRD is dominantly of sand size between 63 μm and 2000 μm (Bigg et al, 2008;Gorbarenko et al, 2008;Malakhov et al, 2009), whereas that for drop-stones should be larger than sand, i.e. N2000 μm Selvaraj et al, 2012).…”