Responses of the Okhotsk Sea environment and sedimentology to global climate changes at the orbital and millennial scale during the last 350 kyr

Deep-Sea Research II 61-64 (2012) 73–84

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Responses of the Okhotsk Sea environment and sedimentology to global climate changes at the orbital and millennial scale during the last 350 kyr Sergey A. Gorbarenko a,, Naomi Harada b, Mikhail I. Malakhov c, Tatyana A. Velivetskaya d, Yuriy P. Vasilenko a, Aleksandr A. Bosin a, Aleksandr N. Derkachev a, Evgenyi L. Goldberg e,y, Aleksandr V. Ignatiev d a

V.I. II’ichev Pacific Oceanological Institute, Far East Branch of Russian Academy of Science, Vladivostok, Russia Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan c North-Eastern Interdisciplinary Scientific Research Institute, Far East Branch of Russian Academy of Science, Magadan, Russia d Far Eastern Geological Institute, Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia e Limnological Institute of Siberian Branch of Russian Academy of Science, Irkutsk, Russia b

a r t i c l e i n f o

abstract

Available online 27 May 2011

We measured productivity proxies (chlorin, carbonate and organic carbon, opal, and biogenic Ba content) and lithophysical proxies (magnetic susceptibility, water content, density, and coarse sediment fraction) in sediment of central Okhotsk Sea core PC-7R. The age model covering the last 350 kyr of this core was constructed by correlating the dated series of relative paleointensity lows recognized in geomagnetic intensity records, marine isotope stage (MIS) boundaries determined in broad variations of the lithophysical and productivity proxies, and tephrochronology. The orbital changes of the lithophysical and productivity proxy stacks lag behind Northern Hemisphere summer radiation by approximately 6.3 and 5.9 kyr, respectively. This lag is consistent with a Milankovich model of climate control by solar radiation through the northern ice sheet volume and sea surface and surrounding land responses, which are fast compared with sedimentological evidence. Productivity proxies of the Okhotsk Sea also demonstrate 52 abrupt, pronounced productivity minima associated with regional climate coolings during the last 350 kyr, which present useful indicators of millennialscale climate changes in this marginal sea. Based on the postulated synchronicity of Dansgaard– Oeschger cycles in the Northern Hemisphere and the established simultaneity of 11 Okhotsk Sea coolings in the last 77 kyr with abrupt severe cold events in the Greenland ice core and North Atlantic Heinrich events, all of these may be regarded as Heinrich-equivalent event anomalies. The Okhotsk Sea events have their counterparts in the records of North Atlantic sediments, the Greenland ice sheet, East Asia summer monsoon, and the Antarctic ice sheet. Probably the Arctic Oscillation was the main factor determining orbital and millennial climate oscillations in the high-latitude Northern Hemisphere, including the Okhotsk Sea region. & 2011 Elsevier Ltd. All rights reserved.

Keywords: Okhotsk Sea Productivity and lithophysical sediment properties Orbital and millennial climate changes Last 350 kyr

1. Introduction Orbital-scale climate changes have been widely identified in Quaternary sediments (Martinson et al., 1987; Bassinot et al., 1994; Lisiecki and Raymo, 2005), Greenland and Antarctic ice cores (Bond et al., 1993; Jouzel et al., 2007), China loess (An and Porter, 1997), speleothems (Wang et al., 2001), and other records, including ¨ sediments from the Okhotsk Sea (OS) (Nurnberg and Tiedemann, 2004). Millennial-scale climate changes superimposed on the orbital  Corresponding author. Tel.: þ 7 4232 31 23 82 (work), þ7 4232 89242365129 (mobile); fax: þ 7 4232 31 25 73. E-mail address: [email protected] (S.A. Gorbarenko). y Deceased.

0967-0645/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.dsr2.2011.05.016

changes demonstrate significant variability of modern climate and underlines the vulnerability of human society. Abrupt climate changes were initially discovered in the Greenland ice core records (Dansgaard et al., 1993) and are now called Dansgaard–Oeschger (DO) oscillations. DO cycles have subsequently been found in many parts of the Northern and Southern Hemispheres (Voelker et al., 2002; Wang et al., 2001; Jouzel et al., 2007). Cold Heinrich events (HE), initially discovered in North Atlantic sediments (Heinrich, 1988) and correlated with the coldest DO stadials (DOS) (Bond et al., 1993), have been recognized in other regions in the Northern Hemisphere (An and Porter, 1997). High-resolution reconstruction of the abrupt climate changes in different regions is of paramount importance for understanding the cause and mechanisms of millennial climate cycles. However, the high-resolution record in the

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Northern Hemisphere encompasses only the last 140 kyr in the Greenland ice cores (North Greenland, 2004) and 224 kyr in the Eastern Asia monsoon records (Wang et al., 2008). The OS, located between the Siberian High and Aleutian Low atmospheric centers, is subject to strong influences of atmosphere processes through variability in East Asian monsoon activity, precipitation and river runoff intensity, and sea ice cover. On the other hand, the hydrology of this marginal basin has extensive water exchange and a strong mutual relationship with the North Pacific Ocean. Abrupt DO oscillations in the OS have been documented during the last 80, 190, and 350 kyr (Gorbarenko et al., 2004; Ono et al., 2005; Goldberg et al., 2005a; Harada et al., 2006; Gorbarenko et al., 2007, 2010a). This study reports new insights into orbital and millennial climate changes during the past 350 kyr using lithophysical and geochemical records in a core from the central OS. We present a sequence of 52 significant millennial-scale climate coolings during the last 350 kyr in the OS, which expands the Northern Hemisphere record of millennial climate oscillations beyond those recorded in Greenland and SE Asia (for the last 140 and 224 kyr, respectively) and has higher resolution and better documentation than North Atlantic records (Heinrich, 1988; van Kreveld et al., 1996; McManus et al., 1999).

2. Hydrology The surface hydrography of the OS is characterized by a large cyclonal gyre with inflow of Pacific water through Kruzenshterna Strait and outflow of cold and freshened water through Bussol’ Strait (Fig. 1). Relatively saline and warm Pacific waters flow northward in the OS as the West Kamchatka Current; after mixing at the northern shelf they turn and flow southward off Sakhalin Island as the East Sakhalin Current and exit the OS as the Oyashio Current (Alfutis and Martin, 1987) (Fig. 1). In addition, Japan Sea saline water flows into the southwestern part of the sea through Soya Strait. The summer surface water temperature varies from

Fig. 1. Location of the core PC-7R and previously studied cores LV 28-40-5 (Gorbarenko et al., 2007), LV 27-2-4 (Gorbarenko et al., 2010b), and 934 and 936 (Gorbarenko et al., submitted for publication). ESC – East Sakhalin Current, NOC – North Okhotsk Current, WKC –West Kamchatka Current, CKC – Compensation Kamchatka Current, SC – Soya Current, and OC-Oyashio Current.

5 to 13 1C, and its salinity from 31.5 to 33.2 psu, being influenced mostly by discharge of the Amur River (Kitani, 1973). A significant temperature-minimum layer ( 1.7 to 1.0 1C) at 50–150 m depth, called the dichothermal layer or subsurface water, forms during winter, mixing with surface water and persisting during summer time. Winter sea ice formation and brine rejection on the northern and western shelves create the cold, high-density Shelf Derived Water (SDW). The Sea of Okhotsk Intermediate Water (SOIW) is thought to be formed by SDW and inflowing Western Subarctic Pacific water, modified by diapycnal mixing within the OS (Yamamoto et al., 2002). SOIW is characterized by low positive temperature of 1–2 1C, low salinity of 33.4–34.3 psu, and high oxygen content of 2.5–6.5 ml/l at 200–1000 m depth (Kitani, 1973; Freeland et al., 1998). Below the SOIW, old and CO2-enriched deep Pacific water enters the OS predominantly via Kruzenshterna Strait and exits mainly through Bussol’ Strait (2300 m deep). The Amur River entering the northern OS supplies most of the freshwater discharge and an extraordinarily high suspended sediment load (Ogi et al., 1995; Anikiev et al., 2001). A large autumn peak in freshwater input reflects the preceding monsoonal precipitation maximum in the Amur drainage area. The main pathway of fluvial discharge is southward in the East Sakhalin Current (Kitani, 1973). As the OS is located between the Siberian High and the Aleutian Low, northerly winds and very low air temperatures in winter result in pronounced winter sea ice coverage (Alfutis and Martin, 1987). The sea ice extent advances by wind-driven ice advection controlled by wind speed (Kimura and Wakatsuchi, 1999). Main sea ice formation starts in November in the northern OS and reaches maximum extent during March, when on average 60–80% of the sea is ice covered (Lisitsin, 1994).

3. Materials and methods Sediment core PC-7R was recovered by a piston corer in the central OS (51116.870 N, 149112.570 E; water depth 1256 m; core length 1722 cm) during cruise MR06-04 of R/V Mirai, supported by Japanese–Russian Project 83 (Fig. 1). The sediment magnetic susceptibility and density were measured using the GEOTEK Core system every 2 cm. The water content was calculated as the ratio of sediment weight loss after drying at 105 1C to the weight of the wet bulk sediment. Weight percentage of the coarse fraction or CF (463 mm and o2000 mm), separated by sediment washing, was calculated as the ratio of CF weight to the weight of the dry bulk sediment. Terrigenous and volcanic grains make up most of this fraction because input of carbonaceous particles (planktonic and benthic foraminifera) is small and siliceous fragments are negligible. Foraminifera amount to less than 1% of the sediment weight, as CaCO3 is less than 1–2% of the bulk sediment in most parts of the studied core whereas CF is 8–16%. Only interglacial and Holocene sediments in the OS have CaCO3 content up to 10–15%, which may increase the minimal CF values during these warm intervals. Because we ignored values of all proxies measured in sediment layers affected by volcanic activity in our time scale records, measured CF values in the core may be used as a rough proxy for Ice Rafted Debris (IRD), carried to the open sea by sea ice and released during ice melting (Gorbarenko et al., 2003; Sakamoto et al., 2005). The chlorin content (CC), a product of chlorophyll-a transformation in the sediment, was measured by a Shimadzu UV–Vis– NIR spectrophotometer UV-3600 according to the modified method of Harris et al. (1996). Water content, CF, and CC were measured every 1 cm. Total carbon content and inorganic carbon were measured every 1 cm by coulometry using an AN-7529 analyzer (Gorbarenko et al., 1998). Total organic carbon (TOC) content was determined by the

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difference between total carbon and inorganic carbon content. d18O and d13C in planktonic foraminifera (Neogloboquadrina pachyderma (s.)) from the 125–250 mm size fraction were measured with a Finnigan-MAT 252 mass spectrometer without preliminary oven drying roasting, according to the standard method with modified sample preparation (Velivetskaya et al., 2009). Technical modifications allow us to analyze d18O and d13C in 10 mg of carbonate with standard deviation of 70.05%. Total Ba content in sediment was determined at a resolution of 1 cm by X-ray fluorescence inductively coupled plasma mass spectrometry (ICP-MS) analysis (Goldberg et al., 2005b). The biogenic (Ba-bio) content was estimated according to the method of Goldberg et al. (2005a) by subtraction of the terrigenous component (Ba-terr.) from the bulk concentration in sediment ¨ (Nurnberg and Tiedemann, 2004). The sediment color reflectance parameter bn (yellow–blue chromaticity), referred to as the Commission International d’Eclairage LAB system, was analyzed onboard by a Minolta CM-2002 reflectance photospectrometer over the wavelength range 400–700 nm. We converted the color bn value into opal ¨ content according to the relation determined by Nurnberg and Tiedemann (2004) in the nearby core LV 28-42-4 (Fig. 1), in which opal (%)¼  14.17 þ4.65bn where r¼ 0.94. Opal content in the OS sediments was accumulated due to by siliceous plankton production, mostly by diatoms (Gorbarenko et al., 2002b). Paleomagnetic investigation of core PC-7R is comprehensively discussed in the paper of Malakhov (personal communication). Spectral analysis of the records, after padding and tapering by 15% to prevent spreading of peaks into adjacent frequencies (Bloomfield, 1976), was done using the software set Statistica-6

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(Stat Soft Inc.) by the FFT method. Hamming’s window with 9 points was used for smoothing of periodograms to derive spectral power. Covariance analyses of the OS lithophysical and productivity proxy were performed using MATLAB Xcov estimates of the cross-covariance sequence of random processes. We use ‘coeff’ to normalize the sequence so the auto-covariances at zero lag are identically 1.0.

4. Age model The age model of core PC-7R sediments was constructed by correlating variations in lithophysical proxies (density, magnetic susceptibility, water content, and CF), chlorin content, and color b* values to marine isotope stages (MISs) (Martinson et al., 1987; Bassinot et al., 1994), sediment geomagnetic intensity records, and tephrochronology (Gorbarenko et al., 2010a). The variation with core depth of density, magnetic susceptibility, water content, CF content, chlorin, and Ba-bio content (Fig. 2) broadly follows the orbitally tuned benchmark d18O records of SPECMAP (Martinson et al., 1987; Bassinot et al., 1994) and encompasses MIS 1–9 and the upper part of MIS 10. The tight correlation of the lithophysical proxies with marine isotope stages and substages suggest a high sensitivity of the OS environment and sedimentation to global climate changes and allows us to determine the boundaries of the MISs in the studied core (Gorbarenko et al., 2010a, Fig. 2). The boundary of the last glaciation and the Bølling-Allerød warming event was marked by an abrupt increase in chlorin content at 47 cm depth in the core due to the climate warming and productivity enhancement at 14.5 kyr BP in the OS (Gorbarenko et al., 2004, 2007). The clear association of these proxies with Younger Dryas cooling suggests that their changes at approximately 32 cm

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Fig. 2. Comparison of broad oscillations of the OS productivity and lithophysical proxies in sediments of core PC-7R versus depth (cm) with (A) standard oxygen isotope curve SPECMAP with Bassinot et al. (1994) time scale, (B) biogenic Ba, (C) chlorin content, (D) coarse fraction, (E) water content, (F) magnetic susceptibility, and (G) density records. Vertical lines indicate boundaries of marine isotope stages (MISs) 1–10; broken lines indicate isotope substages according to Bassinot et al. (1994). Bars indicate ¨ location of dated ash layers K2 (Gorbarenko et al., 2004), MR2, and MR3 (Nurnberg and Tiedemann, 2004).

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core depth mark the boundary of the Younger Dryas with Termination 1B at the beginning of the Holocene in the OS (10.2 kyr) (Gorbarenko et al., 2010b). The base of the upper diatomaceous 350

ooze at 13 cm core depth, established by onboard sediment lithological description and color bn changes, allowed us to date this depth point as 5.5 calendar kyr in age according to the opal content and diatom abundance in the OS sediment during the Holocene (Gorbarenko et al., 2002b, 2010b).

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Age, calendar kyr Fig. 4. Orbital-scale and millennial-scale changes of lithophysical proxies and oxygen and carbon isotope ratios of planktonic foraminifera in core PC-7R versus age: (A) Normalized SPECMAP global d18O curve (Bassinot et al., 1994), (B) d18O of N. pachyderma (s.), (C) d13C of N. pachyderma (s.), (D) coarse fraction, (E) water content, (F) density, and (G) North Hemisphere summer insolation at 651N (NHSI) (Berger, 1978). Vertical lines mark MIS boundaries. Shaded bars are abrupt climatic events derived from the productivity proxies (see Fig. 6).

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included density, magnetic susceptibility, CF, and water content. Productivity proxies included CaCO3, total organic carbon, Ba-bio, opal, and chlorin content. Broad oscillations of the lithophysical proxies versus age (Fig. 4) demonstrate good matching with global climate changes by means of correlation with SPECMAP stages and substages (Bassinot et al., 1994): the proxies increased during cold MISs and substages and decreased during warm stages, except for water content, which showed the opposite relationship. These oscillations lag behind the Northern Hemisphere summer radiation changes (Berger, 1978) by approximately 6.3 kyr (Fig. 5). This pattern is consistent with the Milankovich theory and CLIMAP’s view that solar radiation controls climate changes through the volume of northern ice sheets in obliquity and precession cycles (Hays et al., 1976; Ruddiman, 2003). It implies that northern ice sheet variability is the primary control of changes of OS sedimentology on the orbital time scale. Volume and orography of the Northern Hemisphere ice sheets, through their control of air temperature, winds, and precipitation, determine the main features of atmospheric circulation and land conditions that control the production, transportation, and sedimentation of terrigenous

Geomagnetic paleointensity data from this core are discussed by Malakhov (personal communication). To construct our age model (Gorbarenko et al., 2010a), the troughs in the stack of the normalized relative paleointensity records (ChRM/ARM, ChRM/ Jrs, and ChRM/Jp) were correlated with paleomagnetic lows defined in the dated SINT-800 paleointensity stack (Guyodo and Valet, 1999) and paleomagnetic excursions of Thouveny et al. (2004). Ash layers K2, MR2, and MR3 in the core (Fig. 2) were identified by mineralogy and elemental composition (Derkachev et al., 2012) and correlated with dated ashes (Gorbarenko et al., ¨ 2002a; Nurnberg and Tiedemann, 2004). The relationship of sediment depth and age according to composite age model (Gorbarenko et al., 2010a, Table 1) is shown in Fig. 3. 5. Results and discussion 5.1. Orbital oscillations The measured proxies of the OS sediments were separated into two groups to characterize the lithophysical sediment properties and sea primary productivity, respectively. Lithophysical proxies

MIS 1 2 3 4 HE,he H0 H1 H2 H3 H4 H5 H5a H618 H7 H7a H8 HEEA 17 19 20 21 opal (%) LN(Chlor) (µg/g)

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Age, calendar kyr Fig. 6. Orbital-scale and millennial-scale changes of productivity proxies in core PC-7R over the last 350 kyr. (A) Opal content, (B) chlorin content, (C) total organic carbon content, (D) biogenic Ba content, and (E) carbonate calcium content. Shaded bars indicate the 52 abrupt productivity drops/significant climate coolings in the OS (called Heinrich Event Equivalent Events or HEEAs) as indicated by at least two proxies, numbered after McManus et al. (1994). HEEAs are correlated with Heinrich events of Heinrich (1988) during MIS 2 and 3, with cold events in the North Atlantic of McManus et al. (1994) during MIS 4 and 5 and with North Atlantic IRD peaks of during MIS 6 and 7.

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coastal land conditions respond faster to climate and atmosphere circulation changes than do sedimentological processes.

material (Lisitsin, 1978). The formation of the Chinese loess soil sequences was likely determined by similar mechanisms (An and Porter, 1997; Ding et al., 2002). The variability in productivity proxies (Fig. 6) was mainly controlled by regional climate and surface water conditions. Productivity proxies increased during warm stages and substages and decreased during cold periods, consistent with the relationship previously established in the OS (Gorbarenko and Goldberg, 2005). It should be noted that the relationship of opal content (diatom fossil abundance in sediments) to productivity is complicated in OS sediments (Gorbarenko et al., 2002b, 2007). Indeed, the broad opal plateau demonstrates a rather smoothed record from late MIS 5 to early MIS 2, contrary to significant variability in other productivity proxies. Nevertheless, the opal content has pronounced peaks at the beginning of MIS 5 and 9 and late in MIS ¨ 1 (Fig. 6), similar to other OS cores (Nurnberg and Tiedemann, 2004). Orbital responses of the productivity stack to solar radiation are close to those of the lithophysical proxies, but with a smaller time lag of approximately 5.9 kyr (Fig. 5). This difference in lag implies that productivity responds more quickly to solar forcing than does sediment lithology. That is, the sea surface and

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Besides their orbital-scale variability, the productivity proxies display abrupt changes connected with millennial-scale climatic and environmental oscillations (Fig. 6). We make the preliminary assumption that the productivity proxies in the OS respond similarly to regional climate changes at the millennial and orbital scale (Gorbarenko and Goldberg, 2005): OS productivity increases during abrupt climate warming and vice versa. The OS productivity minima were identified by sharp decreases in most of the productivity proxies or at least in two of them (Fig. 6, gray bars); these present distinctive indicators of millennial environmental changes in the OS connected with abrupt regional climate coolings. Abrupt oscillations in biogenic production exported from the surface to the bottom partly determined the corresponding millennial changes of lithophysical proxies (Fig. 4). For comparison with the established abrupt climate changes in the OS

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Fig. 7. (A) Correlation of millennial changes in the chlorin, total organic carbon, biogenic Ba, and CaCO3 content in core PC-7R and core LV 28-40-5 (Gorbarenko et al., 2007), using their respective age models, with the Greenland ice core record (NorthGRIP, 2004) over the last 77 kyr. (B) Comparison of the d18O and d13C of planktonic foraminifera N. pachyderma (s.) in cores PC-7R and LV 28-40-5, d18O and d13C of benthic foraminifera (Uvigerina auberiana) in core LV 28-40-5 (Gorbarenko et al., 2007), and coarse fraction (ice-rafted debris) content in both cores with the China stalagmite d18O record (Wang et al., 2008) for the last 77 kyr. Ages of millennial-scale productivity/climate events (HEEAs) in the OS cores are similar to those in Fig. 6.

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(Gorbarenko et al., 2007), we suggest that all pronounced abrupt cold events in the OS correlate with Northern Hemisphere coolings and may be considered Heinrich-equivalent event anomalies (HEEA). HEEAs 17, 18, and 19 during MIS 4 are thus correlated with cold events C17 (H6), C18, and C19 (H7) of the North Atlantic (Heinrich, 1988; McManus et al., 1994; Lehman et al., 2002), DOS 17–19 in the Greenland ice core records (Johnsen et al., 2001; NorthGRIP members, 2004) (Figs. 6 and 7A), and winter East Asian monsoon intensifications in the China stalagmite d18O records (Wang et al., 2001, 2008) (Fig. 7b). HEEA 18 was weakly observed in the Greenland ice cores and total East Asian monsoon records, but was clearly observed in the stalagmite SB3 record (Wang et al., 2008). HEEAs 20, 21, 23, and 24 during MIS 5 correspond to Heinrich events 7a, 8, 9, and 10 of the North Atlantic (Heinrich, 1988; McManus et al., 1994; Chapman and Shackleton, 1998; Chapman and Shackleton, 1999; Lehman et al., 2002) and with DOS 7a, 8, 9, and 10 of the Greenland record (Landais et al., 2006; NorthGRIP Members, 2004). HEEA C24a, preceding the C24 cooling, is not clearly observed in the Greenland ice core records, but is well recorded in the China cave d18O curves (Fig. 8). HEEA 25, correlated with the C25 event in the North Atlantic cores and European lake sediments (McManus et al., 1994; Chapman and Shackleton, 1999; Lehman et al., 2002; Sirocko et al., 2005), was not a strong cold event and marked the inception of the last glacial after the Eemian interglacial similar to C25. HEEA 26, correlated with insignificant cooling observed in Europe (Sirocko

(Gorbarenko et al., 2007), Fig. 7A shows the productivity/climate millennial oscillations during the last 77 kyr in cores PC-7R and LV 28-40-5 along with their respective age models. For core LV 28-40-5, recovered in the area of East Sakhalin Current influence (Fig. 1), the sedimentation rate during MIS 2 and 3 (7–12 cm/kyr) was greater than that of the central OS core PC-7R (2.8–4.9 cm/ kyr) owing to transportation of Amur River sediment to the west part of the sea. Most of the DO cycles of the Greenland ice core records (Dansgaard et al., 1993; NorthGRIP members, 2004) and all Heinrich events of the North Atlantic record (Heinrich, 1988) were also found in cores LV 28-40-5 and PC-7R with time resolution of 80–140 and 150–350 yr, respectively; these are shown in Fig. 7a as light gray and dark gray bars, respectively. Significant OS cooling at 8–8.5 kyr BP can be correlated with the 8.2 kyr cooling in the Greenland record (O’Brien et al., 1995). Abrupt OS cooling episodes (Fig. 7A) for the last 77 kyr in the two core age models correlate well with Heinrich events 0 (Younger Dryas), 1–5, 5a, 6, 7, and 7a of the North Atlantic (Heinrich, 1988; Bond et al., 1993), related to severe DOS in the Greenland, and most DO cycles (NorthGRIP Members, 2004), which is consistent with synchroneity of millennial climate cycles in the Northern Hemisphere (Voelker et al., 2002; Rohling et al., 2003). The pronounced cold events in Fig. 6, numbered 17–60 after McManus et al. (1994), were found in the PC-7R record during MIS 4–10. Based on the synchroneity of these events in the Northern Hemisphere (Rohling et al., 2003), including the OS

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et al., 2005), occurred at the beginning of the MIS 5e warming (Fig. 6). HEEA 27 can be correlated with Heinrich event 11 in North Atlantic sediments (Heinrich, 1988; de Abreu et al., 2003), and HEEA 29, 30, 33, 35, 37, and 39 (Fig. 6) might correspond to the cooling events of h8, h9, h10, h11, h12, and h13, respectively, shown by IRD peaks in the North Atlantic cores (van Kreveld et al., 1996). Abrupt OS productivity changes during Terminations IV, II, and I (Fig. 6) show common patterns, with HEEA 59, 27, and 1 corresponding to Heinrich event 1, and HEEA 58, 26, and 0 to Younger Dryas cooling of Termination I, respectively. During Terminations IV, II, and I the increases in opal content, represented mostly by diatom remnants, lag by 6–8 kyr the abrupt climate warmings (equivalents of the Bølling/Allerød of T I), presented by strong rises of chlorin and CaCO3 content (Fig. 6), consistently with available OS results during the last deglaciation–Holocene (Gorbarenko et al., 2002b; Seki et al., 2004). Fig. 8 compares the HEEAs in the productivity and lithophysical stacks of core PC-7R with the Greenland millennial cycles in the GICC05 age model (NorthGRIP Members, 2004), East Asia monsoon oscillations (Wang et al., 2008), and Antarctic temperature from a high-resolution deuterium profile of the Dome C ice core (Jouzel et al., 2007). Within the limits of age model errors (2–5 kyr), the HEEAs 0–41 demonstrate good graphic correlation with the more significant millennial-scale coolings in the d18O monsoon record (Wang et al., 2008) and Greenland NGRIP d18O curve. The sequence of 25 millennial oscillations in high-resolution East Asian monsoon records of Wang et al. (2008) during the last interglacial–glacial cycle (130–15 kyr BP) is consistent with Greenland millennial-scale cycles (NorthGRIP members, 2004), 15 Heinrich events in the North Atlantic, and 17 HEEAs in the OS. The sequence of 24 cycles in the East Asian monsoon during the previous interglacial–glacial cycle (225–130 kyr BP) corresponds to 15 HEEAs in the OS. Seventeen HEEAs were found in the OS during the still earlier interglacial–glacial cycle of 334–225 kyr BP) (Fig. 8). The average frequency of HEEAs in the OS for the last 350 kyr, showing 6.7-kyr periodicity, is close to that of IRD peaks in North Atlantic sediments during the last 500 kyr (McManus et al., 1999). Blunier and Brook (2001) concluded on the basis of a precise chronological matching of ice core records between Greenland and Antarctica that the onset of the seven major abrupt warmings in Antarctica during the last 90 kyr preceded the onset of Greenland warmings by 1.5–3.0 kyr, which might reflect interhemispherical forcing by changes in the oceanic meridional overturning circulation. It has been proposed that this temporal offset of climate changes on millennial time scales between the hemispheres was driven by a ‘‘bipolar seesaw’’ mechanism (Broecker, 1998). Based on correlation of the CH4 records in the Greenland ice core (NorthGRIP Members, 2004) and Antarctic Dome C ice core (EPICA), large DO events recorded in Greenland have been shown to have more symmetrical Antarctic counterparts (Jouzel et al., 2007). The record from OS core LV 28-40-5 during the last 75 kyr shows that significant abrupt cold events in the OS happened nearly simultaneously with warm periods in Antarctica (Gorbarenko et al., 2007). Although the age model of core PC-7R sediments cannot provide precise dating of millennial climate cycles, most HEEAs during the last 350 kyr can be matched with the significant climate changes in the Antarctic Dome C ice core record (Jouzel et al., 2007) within the limits of the core PC-7R age model error (Fig. 8). 5.3. d18O and d13C in planktonic foraminifera Broad oscillations in d18O of planktonic foraminifera N. pachyderma (s.) (d18Opf) in the core PC-7R sediments demonstrate a pattern of variability that sometimes significantly differs from the standard oxygen isotopic chronostratigraphic curves of Martinson

et al. (1987) and Bassinot et al. (1994) (Figs. 4 and 7b). On the other hand, the broad variability in d18O of benthic foraminifera (d18Obf) is nearly consistent with standard oxygen isotopic curves, including isotopic stages and substages (Fig. 7b, Gorbarenko et al., 2004; ¨ Nurnberg and Tiedemann, 2004; Sakamoto et al., 2005). It should be noted that broad oscillation in d18Opf of core LV 28-40-5, located under the influence of the East Sakhalin Current and not very far from PC-7R (Fig. 1), is nearly consistent with d18Obf in core PC-7R and the standard oxygen isotopic curve during MIS 3–1 (Fig. 7b). However, only portions of the d18Opf record in core PC-7R during MIS 5e and MIS 3–1 are closely consistent with the standard oxygen isotope curve (Fig. 4). This evidence allows us to infer that changes in d18Opf in core PC-7R are mostly determined by local peculiarities of the subsurface water at the test calcification depth of N. pachyderma (s.), mostly at the main pycnocline (50–200 m) (Kohfeld et al., 1996; Bauch et al., 2002). The temperature of subsurface water is low in the modern OS, and the influence of temperature changes on d18Opf values was likely insignificant in the past. Therefore, salinity and d18O of subsurface water were the main control of the d18O variability in N. pachyderma (s.) in the past. A preliminary hypothesis is that the d18Opf variability in core PC-7R was significantly driven by sea ice influence in the central OS. It has been shown that during cold MIS 2, the sea ice mostly drifted from the northern area into the central OS (Vasilenko et al., 2006) instead of drifting off Sakhalin Island with the East Sakhalin Current as in modern time (Lisitsin, 1994). Melting of large volumes of sea ice during summer in the central OS during cold MISs may have strongly freshened surface and subsurface water, so that relatively fresh water would penetrate to the pycnocline and deplete d18Opf values in planktonic foraminifera. The d18Opf and planktonic foraminiferal carbon isotope (d13Cpf) records demonstrate significant millennial changes as well (Fig. 4). In many HEEA, d18Opf increased during abrupt coolings and then sharply decreased; however, other HEEA display different types of d18Opf changes. Similar to the IRD changes, the d18Opf records do not show a determinate connection with millennial-scale cooling events in the central OS. 5.4. Possible causes of productivity/climate changes in the OS To understand causes and mechanisms of orbital-scale oscillations in the OS environment and sedimentology, it is important to compare them with periodicities of open oceanic climate changes, governed mostly by ocean dynamic, and low-moderate latitude monsoon changes, which are controlled mostly by atmospheric processes. For the orbital time scale, we calculated spectral densities for the China cave stalagmite d18O (monsoon) records over the last 224 kyr (Wang et al., 2008), ocean d18O records over the last 960 kyr (Bassinot et al., 1994), and the OS productivity and lithophysical proxies stacks over the last 350 kyr (Fig. 9). The oceanic d18O record is dominated strongly by eccentricity frequencies, moderately by obliquity frequencies, and slightly by precession frequencies, indicating that the main drivers in ocean dynamics were associated with ice sheet volume. The spectral density of the East Asia monsoon oscillations was dominated by precession, with predominant 23 kyr and subdominant 19 kyr periods. An eccentricity density is rather obscure and obliquity is absent. Probably the short time record of the East Asian monsoon (224 kyr) suppresses the weight of the eccentricity and obliquity. We infer that tropical/ subtropical monsoons driven by low-latitude summer insolation were more directly controlled by atmospheric processes through continental heating, with a dominant precession signal. This interpretation is consistent with the orbital monsoon hypothesis first proposed by Kutzbach (1981). The OS productivity and lithophysical stacks demonstrate significant, approximately equal eccentricity and obliquity spectral densities and a smaller precession density. Eccentricity density is greater in the lithophysical stack, whereas

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obliquity density is greater in the productivity stack. This result indicates that the OS sediment lithology was more strongly governed by mechanisms associated with ice sheet volume, similar to oceanic dynamics, and that productivity connected with surface environmental changes was more strongly forced by processes associated with obliquity cycles. Approximately similar to the OS proportions of eccentricity, obliquity, and precession densities have been found in the orbital spectral analyses of trace elements in sediments of northern Asia (East Siberia) and Lake Baikal (Goldberg et al., 2000; Goldberg, 2008). The OS and Siberian records both show orbital spectral densities that are intermediate between oceanic and monsoon patterns, indicating that the OS and Siberian climate and environmental changes were driven both by mechanisms connected with ice sheets and oceanic dynamics and by the atmosphere dynamic of the high-latitude Northern Hemisphere. The relationship of the orbital-scale productivity to regional climate changes in the OS has been studied on the basis of results from several sediment cores recovered in the different parts of the sea (Gorbarenko and Goldberg, 2005). Today, sea ice in the OS

strongly suppresses its winter productivity. Formation of sea ice and its spatial and seasonal extension in the OS are governed by variability in the intensity and location of the Siberian High and Aleutian Low related with winter East Asian monsoon activity (Alfutis and Martin, 1987; Kimura and Wakatsuchi, 1999). Activation in the winter East Asian monsoon during cold MISs are thought to strongly increase sea ice formation and its extension (Gorbarenko et al., 2003; Sakamoto et al., 2005) that suppress productivity. According to available data, sea ice cover was not perennial in the central and southern OS even during the last glacial maximum, and ice melted during summer everywhere in the northern OS (Vasilenko et al., 2006; Gorbarenko et al., 2010b). The essential for high productivity nutrients were supplied in the OS by the inflowing of the Pacific water and riverine input (Luchin et al., 1993; Chen et al., 2004). The Amur River with its vast East Asian watershed area transports the large quantity of nutrients and especially silica acid into the OS with its runoff (Anikiev et al., 2001). The volume of runoff and associated nutrient input into the OS were strongly determined by the

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summer monsoon and decrease during the summer monsoon weakening. Experimental results show that OS productivity decreased during cold MISs and increased in warm stages (Gorbarenko and Goldberg, 2005), consistent with both sea ice cover and nutrient supply changes in the OS at orbital time scales. Millennial-scale cycles have been explained by internal changes of climate system forcing mechanisms such as North Atlantic Deep Water formation and associated meridional overturning circulation (Broecker, 1994) through the thermal bipolar seesaw hypothesis of a north–south teleconnection (Broecker, 1998; Blunier and Brook, 2001). The tight correlation of OS millennial-scale environment changes and climate cycles in Greenland and the East Asian monsoon (Fig. 8) allows us to suggest that abrupt changes in these regions were strongly controlled both by the mechanisms coupled with ocean dynamic and by mechanisms related to variability of Northern Hemisphere atmosphere circulation such as an intensity and position of main pressure cells and air temperature. Records of the productivity and environmental changes from cores PC-7R and LV 28-40-5 during the last 77 kyr (Fig. 7B) allow us to consider possible causes of the millennial variability in the OS on the basis of established abrupt productivity drops/cooling events (Fig. 7A). The CF records in both cores may be used as an IRD proxy and indicator of sea ice cover. Although broad oscillations of IRD in both cores clearly show orbital scale variability (Figs. 2 and 7B), this proxy does not clearly demonstrate millennial-scale cycles (Fig. 7B). High-resolution investigation of the climate and environmental changes in different parts of the OS during the Last Glacial Maximum, deglaciation and the beginning of Holocene show that in cores from central areas (cores 936, 934, Fig. 1) some IRD values decreased during short cold periods such as Heinrich event 1 and the Younger Dryas, and some increased during the following short-lived warmings (Gorbarenko et al., submitted for publication). Possibly this pattern of millennial IRD variability in these areas was connected with longer seasonal duration of sea ice cover during the short coolings and enhancement of sea ice melting during warmings accompanied by increased IRD accumulation, as in the northern core LV 27-2-4 (Gorbarenko et al., 2010b). Millennial changes in the IRD record in western core LV 28-40-5 display variability similar to this pattern, and central core PC-7R does not show a definite pattern of IRD variability during HEEAs (Fig. 7B). That allows us to preliminary suggest more extensive sea ice cover in the OS during HEEAs, similar to the orbital-scale patterns of variability. Trace-element analyses of core PC-7R show millennial-scale decreases in land humidity around the OS, including the Amur River area, during HEEAs (Goldberg E.L., personal communication). Therefore, decreases in the nutrient supply to the OS by Amur River runoff during HEEAs may also link suppression of surface productivity to summer monsoon variability. Records of cores PC-7R and LV 28-40-5 show that productivity minima/ climate coolings are closely matched with drops in the East Asian summer monsoon (Fig. 7B). This confirms the above mentioned suggestion that the millennial changes in OS productivity and regional climate were strongly controlled by the atmospheric mechanisms, mainly related to the location and intensity of the regional atmospheric cells, and was possibly governed by the mechanisms similar to those on the orbital time scale. It has been postulated that decadal variability in the strength and location of the Siberian High and Aleutian Low is forced by the Arctic Oscillation (Overland et al., 1999) and the Pacific Decadal Oscillation (Mantua et al., 1997). The Arctic Oscillation is suggested to be the major climate forcing mechanism of the high-latitude Northern Hemisphere (Wallace, 2000), and the Pacific Decadal Oscillation is suggested to provide a strong ocean–atmosphere ˜o-Southern Oscillation (ENSO) teleconnection between the El Nin

cycle of the tropical surface Pacific with meteorological and oceanic changes in the North Pacific (Trenberth and Hurrell, 1994). Small precession peaks in the spectral density distribution of the OS productivity and lithophysical stacks (Fig. 9) indicate that influence of ENSO and the East Asian summer monsoon on the OS climate and environment conditions was less significant in comparison to the Arctic Oscillation. Probably the Arctic Oscillation was the main factor determining the high-latitude North Hemisphere orbital and millennial climate oscillations, including the northeastern Asia landmasses and the OS.

6. Conclusion The broad oscillations of the lithophysical proxies (magnetic susceptibility, water content, density, and coarse fraction/ice-rafted debris) and productivity proxies (chlorin, biogenic Ba, opal, and carbonate and organic carbon content) in sediment of the OS core PC-7R showed excellent correlation with standard oxygen isotope curves and global climate changes at the orbital time scale. Our age model of the core sediments was based on the correlation of the lithophysical proxies with MIS boundaries and correlation of paleomagnetic intensity troughs with dated events of geomagnetic field variations plus tephrochronology (Gorbarenko et al., 2010a). The broad oscillations in OS lithophysical proxies lag behind the Northern Hemisphere summer radiation peak by 6.3 kyr, consistent with orbital control of climate changes through the volume of the northern ice sheets. That implies that orbital-scale changes of OS sediment lithology were primarily controlled by northern ice sheet volume and orography through climatic variability of surrounding lands and the generation, transport, and deposition of terrigenous material. The broad oscillations in the OS productivity proxies lag behind the Northern Hemisphere summer radiation by 5.9 kyr, indicative of faster responses of surface water and surrounding land conditions to changing insolation. Productivity proxies demonstrate in addition to the orbital trends a sequence of 52 abrupt productivity minima/climate coolings in the OS during the last 350 kyr. Given their synchroneity with similar climate changes in the Northern Hemisphere (Voelker et al., 2002; Rohling et al., 2003; Gorbarenko et al., 2007), we regard these as Heinrich equivalent event anomalies (HEEAs). The cold HEEAs have counterparts in the North Atlantic coolings identified by IRD peaks (Heinrich, 1988; McManus et al., 1994; van Kreveld et al., 1996), Greenland ice core records (Johnsen et al., 2001; NorthGRIP Members, 2004), China stalagmite d18O records (Wang et al., 2008), and the Antarctic Dome C ice core record (Jouzel et al., 2007). The d18O and d13C values of planktonic foraminifera reflecting subsurface waters, demonstrate orbital and millennial variability as well. However, broad oscillations in the d18Opf records sometimes significantly differ from the standard SPECMAP curve. Millennial changes in the d18Opf records, similar to the IRD values, do not all closely match millennial coolings in the central OS. Melting of extensive sea ice in summer in the central OS during cold MISs may strongly freshen surface and subsurface water to depths that affect planktonic foraminifera d18O values. Spectral analyses of the OS productivity and lithophysical proxy stacks demonstrate significant, approximately equal eccentricity and obliquity spectral density peaks and a smaller precession peak. In the lithophysical stack, the eccentricity density somewhat exceeds the obliquity density whereas the converse is true in the productivity stack. This indicates that the OS sediment lithology, like ocean dynamics, was more strongly governed by mechanisms associated with ice sheet volume and that productivity, connected with surface environmental changes, was more strongly forced by processes associated with obliquity

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cycles. Patterns of orbital spectral densities in the OS and northeast Asia records are both intermediate between the oceanic and monsoon patterns, which may indicate that the OS and Siberian climate and environmental changes share driving mechanisms connected with ice sheets, oceanic dynamics, and atmosphere dynamics of the high-latitude Northern Hemisphere. Our high-resolution experimental data suggest that the millennial-scale OS productivity and environmental changes were closely related to regional climate changes. During OS cold periods, HEEAs and intensified sea ice coverage and decreased nutrient input from reduced precipitation in East Asia led to decreased productivity in this marginal basin. Millennial-scale cycles have been explained by changes in climatic forcing mechanisms such as North Atlantic Deep Water formation (Broecker, 1994) through the thermal bipolar seesaw hypothesis of a north–south teleconnection (Broecker, 1998; Blunier and Brook, 2001). Our core results and the tight correlation of OS millennial climate changes with ones in Greenland and the East Asian monsoon lead us to suggest that abrupt climate changes in these regions were strongly controlled by mechanisms coupled with ocean dynamic and by mechanisms related to variability of the Northern Hemisphere atmosphere circulation. The Arctic Oscillation may be a major climate forcing mechanism for the high-latitude Northern Hemisphere (Wallace, 2000) that links abrupt climate changes in the North Atlantic, Greenland, northeast Asia, and the Okhotsk Sea.

Acknowledgments We are grateful to Captain Akamine and the crew of R/V Mirai for their help with sediment collection in the Okhotsk Sea during the MR06-04 cruise. This research work is the result of Collaborative Research between POI and JAMSTEC and was supported by JSPS and RFBR (Grant 06-05-91576 JP). This work was supported by the Russian Foundation for Basic Research (10-0500160a) and the integrated grants of Siberian and Far Eastern Branches of the Russian Academy of Science (106 and 09-II-CO07-003). References Alfutis, M.A., Martin, S., 1987. Satellite passive microwave studies of the Sea of Okhotsk ice cover and its relation to oceanic processes. J. Geophys. Res. 92, 13013–13028. An, Z., Porter, S., 1997. Millennial-scale climate oscillations during the last interglaciation in central China. Geology 25, 603–606. Anikiev, V.V., Dudarev, O.V., Kolesov, G.M., Botsul, A.I., Utkin, I.V., 2001. Factors of mesoscale variability in the distribution of the particulate matter and chemical elements in the Amur River estuary—Sea of Okhotsk waters. Geochem. Int. 39 (1), 64–87. Bassinot, F., Labeyrie, L., Vincen, E., Quidelleur, X., Shackleton, N., Lancelot, Y., 1994. The astronomical theory of climate and the age of the Brunhes– Matuyama magnetic reversal. Earth Planet. Sci. Lett. 126, 91–108. Bauch, D., Erlenkeuser, H., Winckler, G., Pavlova, G., Thiede, J., 2002. Carbon isotopes and habitat of polar planktic foraminifera in the Okhotsk Sea: the ‘carbonate ion effect’ under natural conditions. Mar. Micropaleontol. 45, 83–99. Berger, A.L., 1978. Long-term variations of caloric insolation resulting from the Earth’s orbital elements. Q. Res. 9, 139–167. Bloomfield, P., 1976. Fourier Analysis of Time Series: An Introduction. New York, Wiley, pp. 80–94. Blunier, T., Brook, E.J., 2001. Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period. Science 291, 109–112. Bond, G., Broecker, W., Johnson, S., McManus, J., Labeyrie, L., Jouzel, J., Bonani, G., 1993. Correlation between climate records from North Atlantic sediments and Greenland ice. Nature 365, 143–147. Broecker, W.S., 1994. Massive iceberg discharges as triggers for global climate change. Nature 372, 421–424. Broecker, W.S., 1998. Paleocean circulation during the last deglaciation: a bipolar seesaw? Paleoceanography 13, 119–121. Chen, C.-T.A., Andreev, A., Kim, K.-R., Yamamoto, M., 2004. Roles of continental shelves and marginal seas in the biogeochemical cycles of the North Pacific Ocean. J. Oceanogr. 60, 17–44.

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Chapman, M.R., Shackleton, N.J., 1998. Millennial scale fluctuations in North Atlantic heat flux during last 150,000years. Earth Planet. Sci. Lett. 159, 57–70. Chapman, M.R., Shackleton, N.J., 1999. Global ice volume fluctuation. North Atlantic ice—rafting events and deep ocean circulation changes between 130 and 70 ka. Geology 27, 795–798. Dansgaard, W., Johnson, S.J., Claussen, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, D., Sveinbjornsdottir, A.E., Jouzel, J., Bond, G., 1993. Evidence of general instability of past climate from a 250 kyr ice-core record. Nature 364, 218–220. de Abreu, L., Shackleton, N.J., Schonfeld, J., Hall, M., Chapman, M., 2003. Millennialscale oceanic climate variability off the Western Iberian margin during the last two glacial periods. Marine Geology 196, 1–20. Derkachev, A.N., Nikolaeva, N.A., Gorbarenko, S.A., Harada, N., Sakamoto, T., Iijima, K., Sakhno, V.G., 2012. Characteristics and ages of the volcanic ash layers in the central Okhotsk Sea sediments during the last 350 kyr. Deep-Sea Res. II 61–64, 179–192. Ding, Z.L., Derbyshire, E., Yang, S.L., Yu, Z.W., Xiong, S.F., Liu, T.S., 2002. Stacked 2.6Ma grain size record from the Chinese loess based on five sections and correlation with the deep-sea d18O record. Paleoceanography 17 (3), 1033. doi:10.1029/2001PA000725. Freeland, H.J., Bychkov, A.S., Whitney, F., Tayler, C., Wong, C.S., Yurasov, G.I., 1998. WOCE section P1W in the Sea of Okhotsk 1. Oceanographic data description. J. Geophys. Res. 103 (C8), 15613–15623. Goldberg, E.L., Phedorin, M.A., Grachev, M.A., Bobrov, V.A., Dolbnya, I.P., Khlystov, O.M., Levina, O.V., Ziborova, G.A., 2000. Geochemical signals of orbital forcing in the records of paleoclimates found in the sediments of Lake Baikal. Nucl. Instrum. Methods Phys. Res. A 448 (1–2), 384–393. Goldberg, E.L., Gorbarenko, S.A., Shaporenko, A.D., Bosin, A.A., Leskov, V.Yu., Chebykin, E.P., 2005a. Instability of last Glacial climate from SRXFA data for bottom sediments in the Okhotsk Sea. Nucl. Instrum. Methods Phys. Res. A 543, 284–287. Goldberg, E.L., Gorbarenko, S.A., Shaporenko, A.D., Phedorina, M.A., Artemova, A.V., Bosin, A.A., Zolotarev, K.V., 2005b. SRXFA for element compositions of bottom sediments from the Okhotsk Sea. Nucl. Instrum. Methods Phys. Res. A 543, 280–283. Goldberg, E.L., 2008. Tracer elements and uranium-series isotopes in the bottom sediments of Lake Baikal as geochemical climate proxies for high-resolution reconstructions of regional change. In: Peretz, L.N. (Ed.), Climate Change Research Progress. Nova Science Publishers, Inc., NY, pp. 13–86 (Chapter 1). Gorbarenko, S.A., Chekhovskaya, M.P., Southon, J.R., 1998. Detailed environmental changes of the Okhotsk Sea central part during last glaciation-Holocene. Oceanologiya 38, 305–308 (in Russian). ¨ Gorbarenko, S.A., Nurnberg, D., Derkachev, A.N., Astakhov, A.S., Southon, J.R., Kaiser, A., 2002a. Magnetostratigraphy and tephrochronology of the upper Quaternary sediments in the Okhotsk Sea: implication of terrigenous, volcanogenic and biogenic matter supply. Mar. Geol. 183, 107–129. Gorbarenko, S.A., Khusid, T.A., Basov, I.A., Oba, T., Southon, J.R., Koizumi, I., 2002b. Glacial-Holocene environment of the southeast Okhotsk Sea: evidence from geochemical and paleontological data. Palaeogeogr. Palaeocol. Palaeoecol. 177 (3–4), 237–263. Gorbarenko, S.A., Leskov, V.Yu., Artemova, A.V., Tiedemann, R., Biebow, N., ¨ Nurnberg, D., 2003. Sea ice coverage of the Okhotsk Sea during last glacial and Holocene. Dokl. Earth Sci. 388 (5), 678–682. Gorbarenko, S.A., Southon, J.R., Keigwin, L.D., Cherepanova, M.V., Gvozdeva, I.G., 2004. Late Pleistocene–Holocene oceanographic variability in the Okhotsk Sea: geochemical, lithological and paleontological evidence. Palaeogeogr. Palaeocol. Palaeoecol. 209 (1–4), 281–301. Gorbarenko, S.A., Goldberg, E.L., 2005. Assessment of Variations of Primary Production in the Sea of Okhotsk, Bering Sea, and Northwestern Pacific over the Last Glaciation Maximum and Holocene. Dokl. Acad. Nauk 405 (5), 673–676 (translation). Gorbarenko, S.A., Goldberg, E.L., Kashgarian, M., Velivetskaya, T.A., Zakharkov, S.P., Pechnikov, V.S., Bosin, A.A., Psheneva, O.Yu., Ivanova, E.D., 2007. Millennium scale environment changes of the Okhotsk Sea during last 80 kyr and their phase relationship with global climate changes. J. Oceanogr. 63, 609–623. Gorbarenko, S.A., Harada, N., Malakhov, M.I., Vasilenko, Y.P., Bosin, A.A., Goldberg, E.L., 2010a. Orbital and millennial-scale environmental and sedimentological changes in the Okhotsk Sea during the last 350 kyr. Global Planet. Change 72, 79–85. Gorbarenko, S.A., Psheneva, O.Yu., Artemova, A.V., Matul, A.G., Tiedemann, R., ¨ Nurnberg, D., 2010b. Paleoenvironment changes in the NW Okhotsk Sea for the last 18 thousand years by micropaleontologic, geochemical, and lithological data. Deep-Sea Res. I 57, 797–811. ¨ Gorbarenko, S.A., Nurnberg, D., Tiedemann, R., Artemova, A.V., Goldberg, E.L. The response of the Okhotsk Sea environment to the Orbital-Millennium—Centennial Climate Changes during the Last Glacial Maximum, Deglaciation and Holocene. Paleoceanography, submitted for publication. Guyodo, Y., Valet, J.P., 1999. Global changes in intensity of the earth’s magnetic field during past 800 kyr. Nature 399, 249–252. Harada, N., Ahagon, N., Sakamoto, T., Uchida, M., Ikehara, M., Shibata, Y., 2006. Rapid fluctuation of alkenone temperature in southwestern Okhotsk Sea during past 120 ky. Global Planet. Changes 53, 29–46. Harris, P., Zhao, G., Rosell-Mele, M., Tiedemann, R., Sarnthein, M., Maxell, J.R., 1996. Chlorin accumulation rate as a proxy for Quaternary marine primary productivity. Nature 383, 63–66. Hays, J.D., Imbrie, J., Shackleton, N.J., 1976. Variations in the earth’s orbit: pacemaker of the ice ages. Science 194, 1121–1132.

84

S.A. Gorbarenko et al. / Deep-Sea Research II 61-64 (2012) 73–84

Heinrich, H., 1988. Origin and consequences of cyclic ice rafted in the Northeast Atlantic Ocean during the past 130,000 years. Q. Res. 29, 142–152. Johnsen, S.J., Dahl-Jensen, D., Gundestrup, N., Steffensen, J.P., Clausen, H.B., Miller, H., Masson-Delmotte, V., Sveinbjornsdottir, A.E., White, J., 2001. Oxygen isotope and paleotemperature records from six Greenland ice core stations: Camp Century, Dye-3, GRIP, GISP, Renland and NorthGRIP. J. Q. Sci. 16, 299–307. Jouzel, J., Masson-Delmotte, V., Cattani, O., Dreyfus, G., Falourd, S., Hoffmann, G., Minster, B., Nouet, J., Barnola, M., Chappellaz, J., Fischer, H., Gallet, J.C., Johnsen, S., Leuenberger, M., Loulergue, L., Luethi, D., Oerter, H., Parrenin, F., Raisbeck, G., Raynaud, D., Schilt, A., Schwander, J., Selmo, E., Souchez, R., Spahni, R., Stauffer, B., Steffensen, J.P., Stenni, B., Stocker, T.F., Tison, J.L., Werner, M., Wolff, E.W., 2007. Orbital and millennial Antarctic climate variability over the past 800,000 years. Science 317, 793–796. Kimura, N., Wakatsuchi, M., 1999. Processes controlling the advance and retreat of sea ice in the Sea of Okhots. J. Geophys. Res. 104, 11137–11150. Kitani, K., 1973. An oceanographic study of the Okhotsk Sea: particularly in regard to cold waters. Bull. Far. Sea Fish. Res. Lab. (9), 45–77. Kohfeld, K.E., Fairbanks, R.G., Smish, S.L., Walsh, I.D., 1996. Neogloboquadrina pachyderma (sinistral coiling) as paleoceanographic tracers in polar ocean: evidence from Northeast Wate Polynya plankton tows, sediment traps, and surface sediments. Paleoceanography (11), 679–699. Kutzbach, J.E., 1981. Monsoon climate of the early Holocene: climate experiment with earth’s orbital parameters for 9000 years ago. Science 214, 59–61. Landais, A., Masson-Delmotte, V., Jouzel, J., Raynaud, D., Johnsen, S., Huber, C., Leuenberger, M., Schwander, J., Minster, B., 2006. The glacial inception as recorded in the NorthGRIP Greenland ice core: timing, structure and associated abrupt temperature changes. Clim. Dyn. 26 (2–3), 273–284. Lehman, S.J., Sachs, J.P., Rotwell, A.M., Keigwin, L.D., Boyle, E.A., 2002. Relation of subtropical Atlantic temperature, high-latitude ice rafting, deep-water formation, and European climate 130,000–60,000 years ago. Q. Sci. Rev. 21, 1917–1924. Lisiecki, L.E., Raymo, M.E., 2005. A Pliocene–Pleistocene stack of 57 globally distributed benthic d18O records. Paleoceanology 20, PA1003. doi:10.1029/ 2004PA001071. Lisitsin, A.P., 1978. Processes of Ocean Sedimentation. Nayka, Moscow, p. 392. Lisitsin, A.P., 1994. Ice Sedimentation in the World Ocean. Nayka, Moscow, p. 448. Luchin, V.A., Motorykina, T.S., Matveev, V.I., 1993. Regime of biogenic substances, Hydrometeorology and hydrochemistry of seas, V 9, The Okhotsk Sea, Iss 2, Hydrochemical and oceanological basement of the biological production, Gydrometeoizdat, pp. 56–80. Mantua, N.J., Hare, S.R., Zhang, Y., Wallace, J.M., Francis, R.C., 1997. A Pacific interdecadal oscillation with impacts on salmon production. Bull. Am. Meteorol. Soc. 78, 1069–1079. Martinson, D.G., Pisias, N.G., Hays, J.D., Imbrie, J., Moore, T.C., Shackleton, N.J., 1987. Age dating and the orbital theory of the ice ages: development of a highresolution 0 to 300,000-year chronostratigraphy. Q. Res. 27, 1–29. McManus, J.F., Bond, G.C., Broecker, W.S., Johnsen, S., Labeyrie, L., Higgins, S., 1994. High resolution climate records from the North Atlantic during the last interglacial. Nature 371, 326–329. McManus, J.F., Oppo, D.W., Cullen, J.L., 1999. A 0.5 million-year record of millennialscale climate variability in the North Atlantic. Science 283, 971–975. North Greenland Ice Core Project members, 2004. High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431, 147–151. ¨ Nurnberg, D., Tiedemann, R., 2004. Environmental change in the Sea of Okhotsk over the past 1.1 million years-atmospheric teleconnections to China. Paleoceanography 19, PA4011. doi:10.1029/2004PA001023.

O’Brien, S.R., Mayewski, P.A., Meeker, L.D., Meese, D.A., Twickler, M.S., Whitlow, S.I., 1995. Complexity of Holocene climate as reconstructed from a Greenland ice core. Science 270, 1962–1964. Ogi, T., Musiake, K., Matsuyama, H., Masuda, K., 1995. Global atmospheric water balance and runoff from large river basins. Hydrol. Process. 9, 655–678. Ono, A., Takahashi, K., Katsuki, K., Okazaki, Y., Sakamoto, T., 2005. The Dansgaard– Oescher cycles discovered in the up stream source region of the North Pacific Intermediate Water formation. Geophys. Res. Lett. 32, L11607. doi:10.1029/ 2004GL02260. Overland, J.E., Adams, J.M., Bond, N.A., 1999. Decadal variability of the Aleutian low and its relation to high-latitude circulation. J. Clim. 12 (5), 1542–1548. Rohling, E.J., Mayewski, P.A., Challenor, P., 2003. On the timing and mechanism of millennial-scale climate variability during the last glacial cycle. Clim. Dyn. 20, 257–267. Ruddiman, W.F., 2003. Orbital insolation, ice volume, and greenhouse gases. Q. Sci. Rev. 22, 1597–1629. Sakamoto, T., Ikehara, M., Aoki, K., Iijima, K., Kimura, N., Nakatsuka, T., Wakatsuchi, M., 2005. Ice-rafted debris (IRD) based sea-ice expansion events during the past 100 kyrs in the Okhotsk Sea. Deep-Sea Res. II 52 (16–18), 2275–2301. Seki, O., Ikehara, M., Kawamure, K., Nakatsuka, T., Ohnishi, K., Wakatsuchi, M., Narita, H., Sakamoto, T., 2004. Reconstruction of paleoproductivity in the Sea of Okhotsk over the last 30 kyr. Paleoceanography 19, PA1016. doi:10.1029/ 2002PA000808. Sirocko, F., Seelos, K., Schaber, K., Rein, B., Dreher, F., Diehi, M., Lenne, R., Jager, K., Krbetscher, M., 2005. A last Eemian aridity pulse in central Europe during the last glacial inception. Nature 436, 833–836. Thouveny, N.J., Carcailett, E., Moreno, E., Leduc, G., Nerini, D., 2004. Geomagnetic moment variation and paleomagnetic excursions since 400 kyr BP: a stacked record from sedimentary sequences of the Portuguese margin. Earth Planet. Sci. Lett. 219, 377–396. Trenberth, K.E., Hurrell, J.W., 1994. Decadal atmosphere ocean variations in the Pacific. Clim. Dyn. 9, 303–319. van Kreveld, S.A., Knappertsbusch, M., Ottens, J., Ganssen, G.M., van Hinte, J.T., 1996. Biogenic carbonate and ice-rafted debris (Heinrich layer) accumulation in deep-sea sediments from a North Atlantic piston core. Mar. Geol. 131, 21–46. Vasilenko, Yu.P., Gorbarenko, S.A., Leskov, V.Yu., 2006. The sea ice spatial changes in the Okhotsk Sea during Late Pleistocene and Holocene (MIS 6-1) based on the IRD records. In: Proceeding of the 21th International Symposium on the Okhotsk Sea and Sea Ice, Mombetsu, 19–24 February 2006, pp. 216–219. Velivetskaya, T.A., Ignatiev, A.V., Gorbarenko, S.A., 2009. Carbon and oxygen isotope microanalysis of carbonate. Rapid Commun. Mass Spectrom. 23, 2391–2397. Voelker, A.H.L., Workshop Participants, 2002. Global distribution of centennialscale records for marine isotope stage (MIS) 3: a database. Q. Sci. Rev. 21, 1185–1214. Wallace, J.M., 2000. North Atlantic Oscillation/Annular Mode: two paradigms—one phenomenon. Q. J. R. Meteorol. Soc. 126, 791–805. Wang, Y.J., Cheng, H., Edwards, R.L., An, Z.S., Wu, J.Y., Shen, C.-C., Dorale, J.A., 2001. A high-resolution absolute-dated late Pleistocene monsoon records from Hulu Cave, China. Science 294, 2345–2348. Wang, Y.J., Cheng, H., Edwards, R.L., Kong, X.G., Shao, X.H., Chen, S.T., Wu, J.Y., Jiang, X.Y., Wang, X.F., An, Z.S., 2008. Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years. Nature 451, 1090–1093. Yamamoto, M., Watanabe, S., Tsunogai, S., 2002. Effect of sea ice formation and diapicnal mixing on the Okhotsk Sea intermediate water clarified with oxygen isotopes. Deep-Sea Res. I 49, 1165–1174.