Southeast Pacific Alkenone Paleothermometry Calibration Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Southeast Pacific Alkenone Paleothermometry Calibration Data LAST UPDATE: 4/2009 (Original receipt by WDC Paleo) CONTRIBUTOR: Fredrick G. Prahl, Oregon State University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-041 WDC PALEO CONTRIBUTION SERIES CITATION: Prahl, F.G., et al. 2009. Southeast Pacific Alkenone Paleothermometry Calibration Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-041. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Prahl, F.G., A.C. Mix, and M.A. Sparrow. 2006. Alkenone paleothermometry: Biological lessons from marine sediment records off western South America. Geochimica et Cosmochimica Acta, Vol. 70, pp. 101-117. doi:10.1016/j.gca.2005.08.023 ABSTRACT: An empirical global core-top calibration that relates the alkenone unsaturation index UK'37 to mean annual SST (maSST) is statistically the same as that defined for a subarctic Pacific strain of Emiliania huxleyi (CCMP1742) grown exponentially in batch culture under isothermal conditions. Although both equations have been applied widely for paleoSST reconstruction, uncertainty still stems from two key ecological factors: variability in the details of biosynthesis among genetically distinct alkenone-producing strains, and impacts of nonthermal physiological growth factors on UK'37. New batch culture experiments with CCMP1742 here reveal that UK'37 diverge systematically from the core-top calibration in response to nutrient depletion and light deprivation, two physiological stresses experienced by phytoplankton populations in the real ocean. Other aspects of alkenone/alkenoate composition also respond to these stresses and may serve as signatures of such effects, providing an opportunity to detect, understand, and potentially correct for such impacts on the geologic record. A test case documents that sediments from the Southeast Pacific display the alkenone/alkenoate compositional signature characteristic of cells physiologically stressed by light deprivation. Such an observation could be explained if marine snow provided a major vector of sedimentation for these biomarkers. Late Pleistocene UK'37 records in the Southeast Pacific yield plausible paleotemperature histories of ice-age cooling, but ice-age alkenone/alkenoate signatures fall outside the range of modern calibration samples of similar UK'37. They better match core-top samples deposited beneath waters characterized by much cooler maSST, suggesting key features of ice-age ecology for alkenone-producing haptophytes were different from today, and that the UK'37 index taken alone may misgauge the total range of ice-age cooling at these locations. Analysis of the full spectrum of alkenone/alkenoate compositions preserved in sediments opens up a new opportunity that may improve the accuracy of paleotemperature estimates based on simple UK'37 analysis and help resolve longstanding disagreements between various paleotemperature reconstruction methods. GEOGRAPHIC REGION: Eastern Pacific PERIOD OF RECORD: 175 KYrBP - present FUNDING SOURCES: US National Science Foundation Ocean Sciences Division grants OCE-9730376 to F.G.P. and A.C.M.; OCE-9986306 and 0350409 to F.G.P. DESCRIPTION: Alkenone paleothermometry calibration data from surface samples and 3 piston cores from the eastern Pacific Ocean, offshore of western South America. Surface sample locations given in Table 1. Piston core locations as follows: Core RR9702A-11PC: 46.317°S, 76.538°W, 2825 m depth (subpolar transition zone off southern Chile) Core Y71-6-12P: 16.443°S, 77.563°W, 2734 m depth (eastern boundary current off southern Peru) Core Y69-71P: 0.083°N, 86.482°W, 2740 m depth (equatorial "cold-tongue" upwelling zone) DATA: 1. Table 1. Surface Sediment Alkenone and SST data Code Lat°S Lon°W Water sumSST winSST maSST Core OC %CaCO3 Tot.Alk UK'37 UK'37-T %K37 %K38 ME/K37 EE/ME *a Depth °C *b °C *b °C *b Depth wt% wt% *d °C *e *f *f *f *f RR9702A-01MC3 50.7 77 3964 9.7 7.2 8.7 5.5 0.29 5.6 303 0.37 9.7 52 43 0.253 0.666 RR9702A-08MC2 46.4 76.7 3014 11.9 7.4 10.3 5.5 1 5.4 360 0.42 11.2 51 44 0.226 0.729 RR9702A-12MC2 43.4 76.3 3523 13.5 9.2 11.8 5.5 1.3 1.8 348 0.467 12.6 50 44 0.213 0.711 RR9702A-27MC2 40.5 75.9 3850 15.4 10.5 13.2 5.5 1.2 0.4 399 0.47 12.7 50 44 0.185 0.7 RR9702A-44MC2 35.8 73 172 16.3 10.7 13.6 5.5 2.5 3.3 294 0.488 13.2 53 43 0.183 0.653 RR9702A-50MC1 23.6 73.6 3396 20.4 16 17.8 5.5 0.27 63.4 169 0.64 17.7 53 42 0.118 0.78 RR9702A-60MC1 20.9 81.5 2480 21.4 18 19.4 5.5 0.2 90.5 78 0.707 19.7 *g *g *g *g RR9702A-34MC1 36.5 73.4 133 16.7 11.1 13.9 5.5 3.5 1.2 369 0.479 12.9 51 43 0.141 0.725 RR9702A-48MC3 32.6 73.7 3920 17.4 13.1 15.1 5.5 0.56 23.3 387 0.564 15.4 52 43 0.142 0.794 RR9702A-54MC1 21.4 81.4 1323 21.1 17.9 19.2 5.5 0.2 95.6 239 0.749 20.9 *g *g *g *g RR9702A-77MC1 16.1 77 2588 22.8 16.6 19.4 5.5 1.6 5.7 679 0.677 18.8 53 42 0.078 0.907 RR9702A-80MC4 13.5 76.9 448 21.7 14.7 18 5.5 4.4 0.3 657 0.699 19.4 55 42 0.06 0.779 RR9702A-31MC1 37.7 75.4 3946 17 11.7 14.3 5.5 1.3 0.4 505 0.495 13.4 49 45 0.16 0.751 RR9702A-06MC2 46.9 76.6 3298 11.9 7.4 10.3 0.5 0.89 2.7 376 0.402 10.7 47 48 0.239 0.684 RR9702A-14MC4 43.5 76.5 3471 13.5 9.2 11.8 0.5 1.1 1.6 354 0.453 12.2 47 47 0.202 0.711 RR9702A-20MC7 40 74.5 1055 15.9 10.1 13.2 1.5 1 4.5 452 0.479 12.9 47 48 0.186 0.71 RR9702A-04MC5 47 76.6 3354 11.9 7.4 10.3 2.5 0.92 2.7 399 0.41 10.9 46 48 0.241 0.717 RR9702A-10MC2 46.3 76.5 2879 11.9 7.4 10.3 2 0.85 6.5 398 0.43 11.5 47 47 0.232 0.696 RR9702A-22MC3 40 74.1 430 15.2 9.6 12.9 0.5 1.4 2 479 0.487 13.2 47 48 0.189 0.667 RR9702A-25MC2 39.9 75.9 4087 16.1 10.9 13.6 0.5 1.1 0.5 336 0.489 13.2 46 47 0.182 0.691 RR9702A-39MC3 36.2 73.6 510 16.7 11.1 13.9 2 2.3 1 392 0.507 13.8 49 46 0.174 0.697 RR9702A-42MC1 36.2 73.7 1028 16.7 11.1 13.9 0.5 2.4 4.7 441 0.481 13 50 46 0.186 0.668 RR9702A-46MC1 33.3 73.5 3852 16.9 12.6 14.7 2 0.94 7.8 397 0.533 14.5 49 46 0.17 0.74 RR9702A-52MC1 23.2 73.3 3418 20.4 16 17.8 2.5 0.33 54.2 167 0.633 17.5 51 45 0.125 0.729 RR9702A-62MC1 18.1 79 2937 22.5 17.6 19.7 1.5 0.92 75.7 68 0.698 19.4 53 44 0.106 0.889 RR9702A-72MC1 16.5 76.2 3782 22.8 16.6 19.4 2 0.84 0.5 349 0.696 19.3 52 44 0.083 0.869 RR9702A-74MC1 16.2 76.2 3476 22.8 16.6 19.4 2 1.2 0.1 478 0.675 18.7 53 44 0.088 0.982 RR9702A-66MC1 16.1 77.1 2575 22.9 16.9 19.6 2 1.6 6.4 427 0.677 18.8 53 44 0.095 0.819 RR9702A-68MC1 16 76.4 3228 22.8 16.6 19.4 1.5 1.6 0 513 0.685 19 51 45 0.077 0.886 RR9702A-70MC1 16.7 76 4124 22.8 16.6 19.4 3 0.67 0 270 0.661 18.3 53 43 0.098 0.894 RR9702A-64MC1 17 78.1 2930 22.9 17.4 19.8 2 0.44 55.9 227 0.701 19.5 52 44 0.086 0.982 RR9702A-83MC2 13.2 77.3 1419 22.3 15.9 18.9 2.5 8.9 0 571 0.748 20.9 52 44 0.07 0.89 RR9702A-82MC4 13.7 76.7 264 21.7 14.7 18 2 15 4.4 618 0.736 20.5 52 43 0.062 1.035 VNTR01-19PC -7.9 90.5 3448 27.6 26.8 27.4 3.5 *h *h *h 0.911 25.6 *g *g *g *g VNTR01-9PC 3 110.5 3860 26 22.1 24.1 2.5 *h *h *h 0.876 24.6 *g *g *g *g VNTR01-12GC 3 95.1 3535 26.3 20.3 23.2 3.5 *h *h *h 0.802 22.4 *g *g *g *g VNTR01-10GC 4.5 102 3405 25.4 22.2 24.3 3.5 *h *h *h 0.867 24.3 *g *g *g *g VNTR01-8PC 0 110.5 3791 25.7 21.8 23.4 0.5 *h *h *h 0.868 24.4 *g *g *g *g VNTR01-21GC -9.6 94.6 3710 27.8 27.2 27.7 3.5 *h *h *h 0.908 25.6 *g *g *g *g MANOP-14GC -1 140 3900 27 25.3 26.1 0.5 0.36 80 92 0.957 27 *g *g *g *g *a Negative Numbers are north latitude, i.e. -9.6 = 9.6°N. *b sumSST, winSST, mast, summer, winter, and mean annual SST, respectively. *c Depths measured from top of core liner. Cores settled during transport, so all samples actually taken within the top 3 cm of original sediment–water interface. *d Total C37, C38, and C39 alkenone concentration. (ug/gOC) *e Temperature estimated from calibration equation UK'37 = 0:034T + 0.039 (Prahl et al., 1988) *f Alkenone/alkenoate compositional properties-see text for definition. *g Chromatograms contained interfering peaks which prohibited reliable quantitation of these compositional properties. *h Not determined. 2. Table 2(a) Piston Core RR9702A-11PC alkenone/alkenoate signatures Depth Age UK'37 ME/K37 EE/ME (cm) (kyr) 1.5 0.6 0.463 0.229 0.673 11.5 4.8 0.425 0.269 0.519 21.5 9 0.405 0.268 0.448 31.5 13.1 0.322 0.308 0.522 41.5 17.3 0.29 0.321 0.475 51.5 21.5 0.268 0.31 0.504 61.5 0.262 71.5 0.308 81.5 0.365 91.5 0.348 101.5 0.349 111.5 0.347 121.5 0.363 131.5 0.355 141.5 0.349 151.5 0.376 161.5 0.367 171.5 0.367 181.5 0.33 191.5 0.342 200.5 0.337 210.5 0.323 220.5 0.319 230.5 0.335 250.5 0.334 270.1 0.307 290.5 0.3 310.5 0.265 0.32 320.5 0.264 0.331 330.5 0.259 0.304 350.5 0.35 370.5 0.325 391 0.347 410.5 0.35 430.5 0.342 450.5 0.332 470.5 0.307 500.5 0.307 520.5 0.326 530.5 0.302 550.5 0.296 570.5 0.302 0.326 610.5 0.284 0.311 680.5 0.284 700.5 0.306 720.5 0.305 740.5 0.313 760.5 0.321 3. Table 2(b) Piston Core Y71-6-12P alkenone/alkenoate signatures Depth Age UK'37 %K37 %K38 ME/K37 EE/ME (cm) (kyr) 12.5 4.2 0.712 52 44 0.14 0.868 17.5 6.5 0.71 54 42 0.102 0.78 27 10.8 0.683 54 42 0.101 0.746 32 12.7 0.696 52 43 0.095 0.848 45.5 16.8 0.646 53 43 0.113 0.699 49.5 18.3 0.616 53 43 0.121 0.645 55.5 20.4 0.625 54 42 0.126 0.621 60.5 21.9 0.612 53 43 0.131 0.644 65.5 23.5 0.625 54 42 0.131 0.658 65.5 23.5 0.613 54 42 0.132 0.664 70.5 26 0.626 54 43 0.124 0.762 75.5 28.3 0.624 54 42 0.127 0.707 80.5 31.5 0.622 54 42 0.138 0.599 85.5 37.8 0.627 54 42 0.138 0.596 90.5 44.6 0.639 54 42 0.122 0.596 96.5 50 0.662 54 42 0.122 0.532 100 52.9 0.659 55 42 0.117 0.539 104.5 56.5 0.683 54 43 0.111 0.533 113 60.4 0.678 54 42 0.113 0.521 117.5 62.1 0.678 53 43 0.117 0.476 119.5 62.7 0.674 54 42 0.117 0.513 125.5 66 0.659 54 43 0.126 0.468 130.5 70.9 0.673 54 42 0.132 0.436 135.5 75.8 0.712 54 43 0.125 0.448 140.5 79.9 0.735 54 42 0.127 0.429 145 85 0.738 53 43 0.123 0.429 150 91.1 0.695 54 42 0.117 0.44 155 97.1 0.706 55 42 0.118 0.45 160 103.1 0.689 54 42 0.121 0.466 165 106.6 0.712 54 42 0.115 0.424 170 108.9 0.681 54 42 0.107 0.485 175 111.7 0.714 53 43 0.104 0.44 180 115.7 0.734 53 43 0.091 0.485 186.5 122.8 0.738 52 43 0.086 0.503 194.5 133.8 0.701 51 44 0.1 0.491 201 138.6 0.689 51 45 0.113 0.541 206 141.9 0.704 53 43 0.092 0.505 210 144.8 0.68 52 43 0.102 0.465 216 149.1 0.683 52 44 0.104 0.52 221 152.5 0.657 52 44 0.107 0.466 226 155.7 0.682 52 44 0.092 0.53 231 158.8 0.66 52 43 0.089 0.489 236 162 0.676 52 44 0.092 0.55 241 165.9 0.645 53 43 0.097 0.529 246 170.1 0.673 53 44 0.094 0.56 251 174.1 0.64 53 43 0.105 0.508 4. Table 2(c) Piston Core Y69-71P alkenone/alkenoate signatures Depth Age UK'37 %K37 %K38 ME/K37 EE/ME (cm) (kyr) 7.3 1.1 0.857 55 42 0.069 0.921 10.5 1.5 0.859 54 42 0.066 0.967 18.5 2.6 0.854 55 42 0.057 1.077 40.5 5.6 0.831 55 41 0.056 1.088 50 6.9 0.816 54 43 0.055 1.198 62 8.5 0.797 55 42 0.064 1.026 80.5 11 0.787 55 42 0.058 0.983 100.5 12.8 0.756 54 42 0.056 1.128 120.5 14.5 0.767 55 41 0.055 0.928 139.5 16.2 0.764 55 41 0.056 0.852 149 17 0.771 55 41 0.054 0.905 180 19.2 0.777 56 41 0.059 0.719 201 20.5 0.766 56 41 0.061 0.887 218.5 21.5 0.777 57 39 0.07 0.565 240.5 22.8 0.779 56 41 0.063 0.57 250 23.5 0.79 55 41 0.074 0.528 260.5 24.2 0.801 55 41 0.062 0.628 279.5 26.4 0.814 55 41 0.067 0.651 300.5 29.1 0.827 54 43 0.094 0.562 322.5 31.8 0.809 54 42 0.069 0.668 336.5 33.6 0.82 55 41 0.078 0.514 339 33.9 0.797 57 41 0.082 0.483 348.5 35.1 0.813 55 42 0.078 0.509 357.5 36.2 0.808 56 41 0.074 0.53 361 36.6 0.819 55 42 0.07 0.574 377.5 38.7 0.797 56 41 0.077 0.556 381 39.1 0.785 56 41 0.074 0.568 400.5 41.6 0.809 55 41 0.069 0.607 420 44 0.818 56 41 0.074 0.569 449 47.6 0.833 56 41 0.073 0.531 459 48.9 0.831 56 41 0.077 0.484 482 51.8 0.846 56 41 0.076 0.437 501 54.1 0.819 56 41 0.078 0.565 519.5 56.4 0.84 56 41 0.093 0.406 538.5 58.9 0.816 56 41 0.077 0.467 548.5 60.8 0.799 56 41 0.08 0.428 559.5 62.9 0.796 56 41 0.077 0.476 577.5 66.3 0.809 55 41 0.091 0.405 598.5 70.1 0.806 55 41 0.11 0.346 618 73.5 0.812 56 41 0.089 0.396 637.5 77 0.844 55 42 0.087 0.346 648.5 79 0.869 55 42 0.071 0.413 662.5 81.5 0.859 55 42 0.076 0.401 678.5 84.8 0.862 55 42 0.086 0.422 698.5 89.7 0.864 55 42 0.087 0.397 718.5 95.5 0.874 55 42 0.076 0.436 737.5 100.6 0.866 55 43 0.074 0.44 758.5 105.6 0.85 54 42 0.065 0.489 783 111.9 0.814 56 41 0.065 0.502 800.5 116.7 0.874 56 42 0.061 0.396 818.5 121.5 0.899 55 42 0.053 0.498 838.5 125.4 0.905 54 42 0.039 0.853 858.5 129.2 0.872 54 43 0.052 0.772 878.5 132.9 0.847 54 43 0.064 0.642 898.5 136.6 0.84 54 43 0.063 0.604 919.5 140.4 0.855 54 43 0.052 0.648 938.5 143.9 0.857 54 43 0.046 0.65 958.5 147.4 0.824 54 43 0.052 0.654 980.5 151.1 0.827 54 43 0.049 0.751 1002.5 155 0.843 54 43 0.046 0.819