Japan Sea MD01-2407 Aeolian Silt Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Japan Sea MD01-2407 Aeolian Silt Data LAST UPDATE: 4/2007 (Original receipt by WDC Paleo) CONTRIBUTORS: Kana Nagashima, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2007-041 SUGGESTED DATA CITATION: Nagashima, K., et al. 2006. Japan Sea MD01-2407 Aeolian Silt Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2007-041. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Nagashima, K., R. Tada, H. Matsui, T. Irino, A. Tani, and S. Toyoda. 2007. Orbital- and millennial-scale variations in Asian dust transport path to the Japan Sea. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 247, Issues 1-2, pp. 144-161, 20 April 2007. doi:10.1016/j.palaeo.2006.11.027 ABSTRACT: Orbital- and millennial-scale variations in the Asian monsoon and its probable association with the Dansgaard–Oeschger (D–O) Cycles have been demonstrated by previous studies. However, the origin and nature of such variations are poorly understood. The Japan Sea is located down wind of the arid areas of the Eurasian continent, and thus receives significant amounts of aeolian dust. Consequently, the hemipelagic sediments of the Japan Sea are expected to record a continuous aeolian dust accumulation, which may provide information about the past variations in Asian monsoon. Grain size, flux, and provenance of aeolian dust in the sediments were examined using two sediment cores obtained from the northern and southern parts of the Japan Sea in order to understand the spatial variability of Asian monsoon. Since the silt fraction of the detrital materials in hemipelagic sediments of the Japan Sea is composed predominantly of aeolian dust, the grain size, flux, and provenance of the silt fraction were examined. The Taklimakan Desert–Loess Plateau and Siberia–Northeast China areas were identified as possible source areas of aeolian dust in the sediments of the Japan Sea based on the Electron Spin Resonance (ESR) signal intensity and crystallinity of quartz. Moreover, the relative contribution of aeolian dust from each source area was estimated based on the ESR signal intensity and crystallinity of quartz. Aeolian dust fluxes from the two source areas at the southern site were then estimated. Grain size and flux of eolian dust at the northern site, and fluxes of aeolian dust from two source areas at the southern site show orbital-scale variations in harmony with the insolation change at 30° N in June. These results indicate orbital-scale changes in the extent of the arid area and/or frequency of dust storms in the Taklimakan Desert–Loess Plateau and Siberia–Northeast China areas, and suggest that southward (northward) shifts of the westerly jet axis occurred together with either intensified (weakened) winter monsoon, decreased (increased) winter precipitation in the Siberia–Northeast China area, or southeastward (northwestward) shifts of summer monsoon limit during periods of smaller (larger) insolation at 30° N in June. In addition to these orbital-scale variations, millennial- scale variations possibly associated with the D–O Cycles are observed in the grain size record of aeolian dust at the two sites. Based on analogy with orbital-scale variations, these millennial-scale variations are considered to reflect millennial-scale changes in the position of the westerly jet axis together with the changes either in winter monsoon intensity, winter precipitation, or position of summer monsoon limit. Our results suggest N–S oscillations in the westerly jet and summer monsoon limit, and changes in the intensity of the winter monsoon on orbital and millennial timescales. ADDITIONAL REFERENCES: Chronostratigraphic information described in: Yokoyama, Y., Y. Kido, R. Tada, I. Minami, R.C. Finkel, and H. Matsuzaki. 2007. Japan Sea oxygen isotope stratigraphy and global sea-level changes for the last 50,000 years recorded in sediment cores from the Oki Ridge. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 247, Issues 1-2, pp. 5-17, 20 April 2007. doi:10.1016/j.palaeo.2006.11.018 Kido, Y., I. Minami, R. Tada, K. Fujine, T. Irino, K. Ikehara, and J.-H. Chun. 2007 Orbital-scale stratigraphy and high-resolution analysis of biogenic components and deep-water oxygenation conditions in the Japan Sea during the last 640 kyr. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 247, Issues 1-2, pp. 32-49, 20 April 2007. doi:10.1016/j.palaeo.2006.11.020 GEOGRAPHIC REGION: Northwest Pacific PERIOD OF RECORD: 148 KYrBP - present FUNDING SOURCES: This research is supported by grants-in-aid for scientific research of the Japan Society for Promotion of Science (nos. 12308026, 16634012, and 15310008) awarded to R. Tada. DESCRIPTION: Silt fraction size data for the last 148 KYr in the Japan Sea. Core MD01-2407: 37 04 00 N, 134 42 11 E, 932m. depth. This site is located near the top of Oki ridge approximately 200 km north of southern Honshu, mainland of Japan, and free from the influence of turbidites. Median diameters of silt fraction (>4um) for 196 detrital samples of MD01-2407 core which covers the last 148 kyr were measured. Silt fraction of the detrital materials in hemipelagic sediments of the Japan Sea is considered to be composed predominantly of aeolian dust (Nagashima et al., 2007). Grain size of silt fraction for MD01-2407 core samples show millennial-scale variations possibly associated with the Dansgaard-Oeschger Cycles, suggesting millennial-scale changes in the position of the westerly jet axis together with the changes in Asian winter/summer monsoon intensity. Chronostratigraphic information described in Yokoyama et al. 2007 and Kido et al. 2007. DATA: Table 1. Median diameter of silt fraction (>4um) of detrital samples from MD01-2407 core. The age model for the last 150 kyr part of the MD01-2407 core was constructed using four tephra layers (K-Ah= 7.2 ka after Tada et al., 1999; AT= 29 ka after Miyairi et al., 2004; Aso-4= 88 ka after Matsumoto et al., 1991.; and Aso-3=133 ka, after Chun et al., 2004), seven AMS 14C dates (Yokoyama et al. 2007), and eight MIS (Marine Isotope Stage) events (4.0, 5.0, 5.1, 5.4, 5.5, 6.0, 6.2, and 6.4) as age controlling datums (Kido et al. 2007). Column 1: Average depth (cmbsf) Column 2: Calendar age (Kyr) Column 3: Median diameter of silt fraction (um) Depth(cm) Age(KYr) Silt(um) 4.4 0.08 8.6 11.9 0.21 8.2 16.9 0.3 8.5 21.9 0.39 8 25.6 0.46 8.4 35.6 0.64 8.5 41.9 0.75 7.6 45.6 0.82 8 51.9 0.93 7.8 111.9 2.47 7.8 115.6 2.62 7.4 120.6 2.82 8.4 126.9 3.06 8.3 129.4 3.16 8.8 135.6 3.41 8.3 138.1 3.51 8.4 143.1 3.71 8.8 148.1 3.94 8.3 155.6 4.29 9.2 160.6 4.52 8.1 165.6 4.76 9.4 170.6 4.99 7.6 175.6 5.22 8.2 180.6 5.46 8.8 185.6 5.69 8.3 260.6 10.22 7.1 264.4 10.49 7.8 271.9 11.02 6.9 277.8 11.5 7.6 280.6 11.73 8 285.6 12.15 8.2 290.6 12.56 8 295.6 12.98 8.1 301.9 13.57 9.1 305.6 14.03 8.6 311.9 14.8 9.1 320.6 15.88 8.4 325.6 16.49 8.8 329.4 16.95 8.8 335.6 17.72 8.9 340.6 18.34 8.9 345.6 19.03 9.5 350.6 19.9 8.9 356.9 20.99 8.7 361.9 21.85 8.6 365.6 22.5 8.7 370.6 23.37 8.5 375.6 24.24 9.6 380.6 25.07 8.9 385.6 25.87 8.9 390.6 26.68 9.3 394.7 27.34 8.7 425.6 30.65 8.3 429.4 31.25 8.6 450.6 34.68 8.6 460.6 36.29 7.8 465.7 37.11 8.5 471.9 38.1 8.7 475.6 38.71 8.8 481.9 39.72 8.4 490.8 41.16 8.4 500.6 42.34 7.9 505.6 42.93 8.1 509.4 43.37 8.2 515.6 44.11 7.6 520.6 44.7 7.9 530.6 45.88 8.4 535.6 46.48 8.5 541.9 47.21 8.3 545.6 47.66 8.4 550.6 48.25 8.2 555.6 48.84 8.5 560.6 49.43 8.9 565.6 50.02 8 571.9 50.76 8.4 575.6 51.2 7.9 580.6 51.79 7.7 586.9 52.53 7.4 589.4 52.83 7.9 600.6 54.16 8.9 605.6 54.75 8.9 611.9 55.49 8.7 620.6 56.52 8.9 625.6 57.11 8.7 629.4 57.56 8 635.6 58.3 8.3 643.1 59.26 8.9 650.6 60.44 9 661.9 62.21 8.5 666.9 62.99 8.3 671.6 63.74 8.1 680.6 65.16 8.6 690.6 66.73 9 700.6 68.31 8.2 715.6 70.67 8.1 725.6 72.24 8.3 730.6 73.03 8.2 740.6 74.43 9.2 745.6 75.02 9.1 750.6 75.62 9.2 761.9 76.95 8.3 766.9 77.55 8.4 785.6 79.74 8.9 790.6 80.29 9.1 795.6 80.85 8.6 800.6 81.4 8.4 805.6 81.96 9 810.6 82.51 8.7 815.6 83.07 8.1 824.4 84.04 7.8 835.6 85.29 8.5 840.6 85.85 8.4 875.6 91.06 8 880.6 92.04 7.6 884.4 92.78 8 890.6 94 8.4 895.6 94.98 8.3 905.6 96.94 9.4 910.6 97.92 8.4 915.6 98.9 9 930.6 101.84 9.4 935.6 102.82 9.5 940.6 103.8 8.6 946.9 105.03 7.8 950.6 105.76 8.5 955.6 106.74 8 960.6 107.72 8.4 965.6 108.7 8.3 975.6 110.66 8.3 980.6 111.08 8 985.6 111.42 7.7 990.6 111.75 8.6 999.4 112.33 8.8 1000.8 112.43 8.5 1010.6 113.09 8.5 1020.6 113.75 8.4 1025.6 114.09 8.9 1030.6 114.42 8.9 1035.6 114.76 8.8 1040.6 115.09 8.7 1045.6 115.42 8.5 1055.6 116.09 9.3 1068.1 116.93 9.2 1073.1 117.26 8.1 1078.1 117.6 8.5 1081.9 117.85 9.1 1085.6 118.1 9 1090.6 118.43 8.8 1095.6 118.76 9.1 1103.1 119.27 7.4 1108.1 119.6 7.8 1113.1 119.93 8.9 1118.1 120.27 9 1123.1 120.6 8 1128.1 120.94 9.2 1130.6 121.1 7.5 1136.9 121.52 7.5 1141.9 121.85 7.4 1146.9 122.19 8.2 1151.9 122.52 7.7 1154.4 122.69 8.1 1163.1 123.27 8 1183.1 125.01 8.8 1193.1 126.01 9 1203.1 127.02 8.8 1208.1 127.52 8.6 1213.1 128.02 7.5 1219.4 128.65 8.2 1225.6 129.27 8.3 1235.6 130.28 8.3 1245.6 131.29 8.6 1250.6 131.8 9.2 1255.6 132.3 9.2 1260.6 132.81 8.9 1265.6 133.35 8.4 1270.6 133.91 8.5 1275.6 134.47 9 1277.9 134.72 8.6 1283.1 135.32 8.4 1285.6 135.62 8.6 1290 136.14 8.5 1300.6 137.4 8.6 1305.6 137.99 8.7 1318.1 139.48 8.9 1324.4 140.22 8.7 1328.1 140.66 8.5 1345.6 142.74 8.4 1350.6 143.33 8.4 1355.6 143.93 8.3 1360.6 144.52 8 1365.6 145.11 8.1 1370.6 145.71 8.6 1375.6 146.3 8.3 1380.6 146.89 8.8 1385.6 147.49 8.6 1390.6 148.08 8.5