# Juan de Fuca Ridge Mass Flux Data over the Last 500 ka #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/21009 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/by_contributor/costa2017/costa2017-38pc.txt # # Archive: Paleoceanography # # Parameter_Keywords: lithology, radiogenic isotope #--------------------------------------- # Contribution_Date # Date: 2016-12-01 #--------------------------------------- # Title # Study_Name: Juan de Fuca Ridge Mass Flux Data over the Last 500 ka #--------------------------------------- # Investigators # Investigators: Costa, K.M.; McManus, J.F. #--------------------------------------- # Description and Notes # Description: #--------------------------------------- # Publication # Authors: Costa, K.M. and J.F. McManus # Published_Date_or_Year: 2017 # Published_Title: Efficacy of 230Th normalization in sediments from the Juan de Fuca Ridge, northeast Pacific Ocean # Journal_Name: Geochimica et Cosmochimica Acta # Volume: 197 # Edition: # Issue: # Pages: 215-225 # Report Number: # DOI: 10.1016/j.gca.2016.10.034 # Online_Resource: # Full_Citation: # Abstract: 230Th normalization is an indispensable method for reconstructing sedimentation rates and mass fluxes over time, but the validity of this approach has generated considerable debate in the paleoceanographic community. 230Th systematics have been challenged with regards to grain size bias, sediment composition (CaCO3), water column advection, and other processes. In this study, we investigate the consequences of these effects on 230Th normalization from a suite of six cores on the Juan de Fuca Ridge. The proximity of these cores (<30 km) suggests that they should receive the same particle rain rate of sediment, but the steep bathymetry of the ridge leads to substantial sediment redistribution and variable carbonate preservation, both of which may limit the usage of 230Th in this region. Despite anticipated complications, 230Th normalization effectively recon- structs nearly identical particle rain rates from all six cores, which are summarily unrelated to the total sedimentation rates as calculated from the age models. Instead the total sedimentation rates are controlled almost entirely by sediment focusing and winnowing, which are highly variable even over the short spatial scales investigated in this study. Furthermore, no feed- backs on 230Th systematics were detected as a consequence of sediment focusing, coarse fraction variability, or calcium car- bonate content, supporting the robustness of the 230Th normalization technique. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: AGS-1338832 #--------------------------------------- # Site Information # Site_Name: AT26-19 38PC # Location: North Pacific Ocean # Country: # Northernmost_Latitude: 44.97053 # Southernmost_Latitude: 44.97053 # Easternmost_Longitude: -130.60653 # Westernmost_Longitude: -130.60653 # Elevation: -2655 #--------------------------------------- # Data_Collection # Collection_Name: AT26-19 38PC Costa17 # First_Year: 16769 # Last_Year: 479860 # Time_Unit: cal yr BP # Core_Length: # Notes: #--------------------------------------- # Chronology_Information # Chronology: #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth,,,cm,,,,,N ## age_calyrBP age,,,cal yrs before present,,,,,N ## massflux Total mass flux,,,g cm-2 ka-1,,paleoceanography,,,N ## massflux_err_2s Total mass flux,,Two sigma error,g cm-2 ka-1,,paleoceanography,,,N #------------------------ # Data # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Value: NaN depth_cm age_calyrBP massflux massflux_err_2s 0.5 16769 0.536 0.008 4.5 17921 0.918 0.015 8.5 19074 1.361 0.023 12.5 20226 1.375 0.025 16.5 21681 1.344 0.024 18.5 23825 1.345 0.024 20.5 25993 1.158 0.021 22.5 28162 1.314 0.024 24.5 30330 0.805 0.014 26.5 32498 1.194 0.022 28.5 34703 1.088 0.021 30.5 37188 1.045 0.020 32.5 39730 0.940 0.018 34.5 42272 0.863 0.017 36.5 44814 0.853 0.017 38.5 47356 0.802 0.016 40.5 49898 0.748 0.015 42.5 52440 0.783 0.016 44.5 54982 0.722 0.015 48.5 56580 0.713 0.014 52.5 57306 0.792 0.017 56.5 58032 0.784 0.017 60.5 58758 0.800 0.017 64.5 59483 0.829 0.017 68.5 60209 0.951 0.021 72.5 60935 0.928 0.021 76.5 61660 0.927 0.021 80.5 62386 0.863 0.019 84.5 63112 0.852 0.020 88.5 63838 0.841 0.021 92.5 64563 0.877 0.021 96.5 65289 0.759 0.018 100.5 66721 0.788 0.020 102.5 68644 0.804 0.021 104.5 70567 0.819 0.022 106.5 72490 0.854 0.023 108.5 74413 0.816 0.022 110.5 76335 0.796 0.022 112.5 78258 0.685 0.018 114.5 80181 0.705 0.019 116.5 82104 0.690 0.019 118.5 84027 0.603 0.016 120.5 85950 0.627 0.017 122.5 87873 0.624 0.017 124.5 89795 0.609 0.017 126.5 91718 0.528 0.015 128.5 93641 0.510 0.014 130.5 95564 0.510 0.014 132.5 97487 0.513 0.016 134.5 99410 0.492 0.015 136.5 101333 0.514 0.017 138.5 103256 0.413 0.013 140.5 105209 0.451 0.015 142.5 107313 0.465 0.015 143.5 108371 0.415 0.013 144.8 109746 0.583 0.019 146.8 111862 0.933 0.037 148.8 113978 0.661 0.024 150.8 116095 0.532 0.018 152.8 118211 0.619 0.022 154.8 120327 0.562 0.019 156.8 122453 0.414 0.013 158.8 124795 0.464 0.016 160.8 127171 0.428 0.014 162.8 129548 0.576 0.020 164.8 131895 0.843 0.035 166.8 133952 1.423 0.067 168.8 135968 1.447 0.073 170.8 137983 1.213 0.055 172.8 139999 1.318 0.067 174.8 142015 1.045 0.033 176.8 144030 1.086 0.034 178.8 146046 1.214 0.039 180.8 148062 1.275 0.067 182.8 150077 1.235 0.063 184.8 152093 1.237 0.071 186.8 154108 1.277 0.072 188.8 156124 1.139 0.063 190.8 158140 1.362 0.082 192.8 160155 1.223 0.073 194.8 162171 1.288 0.078 196.8 164187 1.118 0.064 198.8 166202 1.121 0.068 200.8 168218 1.082 0.068 202.8 170071 1.026 0.062 204.8 171276 1.012 0.059 208.8 173564 0.835 0.047 212.8 175852 0.718 0.041 216.8 178140 0.630 0.038 220.8 180427 0.519 0.043 224.8 182715 0.549 0.033 228.8 185003 0.548 0.034 232.8 187291 0.597 0.039 234.8 188434 0.525 0.032 236.8 193304 0.484 0.031 238.8 199561 0.459 0.030 240.8 202845 0.474 0.032 242.8 205723 0.445 0.031 244.8 208602 0.421 0.030 246.8 211480 0.417 0.030 248.8 214358 0.501 0.041 250.8 217236 0.722 0.074 252.8 220249 0.620 0.056 254.8 224049 0.702 0.073 256.8 227943 0.496 0.042 258.8 231837 0.442 0.037 260.8 235731 0.432 0.036 262.8 239510 0.472 0.040 264.8 240748 0.364 0.028 266.8 241575 0.328 0.025 268.8 242403 0.340 0.027 270.8 244431 0.862 0.088 272.8 249179 1.401 0.214 274.8 254013 0.966 0.112 276.8 258848 1.933 0.293 278.8 263682 1.420 0.315 280.8 268516 0.947 0.155 282.8 272046 0.759 0.102 288.8 272212 1.212 0.208 303.6 272212 2.969 1.350 295.6 272212 1.930 0.602 315.6 272212 0.583 0.095 292.8 272212 1.385 0.294 307.6 272212 2.269 0.868 311.6 272212 1.663 0.482 299.6 272212 2.317 0.826 284.8 272212 1.088 0.163 319.6 273425 0.520 0.076 321.6 276060 0.559 0.085 323.6 278695 0.575 0.085 325.6 281331 0.751 0.115 327.6 283966 0.723 0.110 329.6 286601 0.462 0.066 331.6 289236 0.471 0.060 333.6 291871 0.477 0.062 335.6 294506 0.488 0.061 337.6 297141 0.531 0.068 339.6 299776 0.544 0.072 341.6 302411 0.675 0.102 343.6 305046 0.626 0.092 345.6 307681 0.611 0.096 347.6 310316 0.602 0.092 349.6 312951 0.576 0.090 351.6 315586 0.485 0.072 353.6 318221 0.462 0.071 355.6 320857 0.483 0.082 357.6 323492 0.459 0.079 359.6 326239 0.437 0.075 361.6 329572 0.509 0.103 363.6 333028 0.527 0.096 365.6 336724 0.560 0.126 367.6 340461 0.552 0.119 369.6 344198 0.550 0.115 371.6 347935 0.748 0.210 373.6 351672 0.818 0.259 375.6 355409 0.652 0.172 377.6 359146 0.792 0.258 379.6 362883 0.733 0.204 381.6 366620 0.742 0.208 383.6 370357 0.491 0.113 385.6 374094 0.802 0.275 387.6 377831 0.721 0.228 399.6 379531 0.602 0.171 389.6 381568 0.706 0.220 395.6 382211 0.687 0.207 393.6 383551 0.504 0.130 391.6 384463 0.688 0.203 397.6 385534 0.663 0.214 401.6 387518 0.587 0.196 403.6 388268 0.581 0.201 405.6 393482 0.535 0.191 407.6 398696 0.524 0.190 409.6 403911 0.496 0.156 411.6 409125 0.534 0.182 413.6 414249 0.741 0.198 415.6 417923 1.184 0.430 419.6 423912 0.820 0.253 423.6 426699 0.888 0.251 427.6 429486 1.172 0.625 431.6 432273 0.821 0.227 435.6 435059 1.358 0.871 439.6 437846 1.213 0.544 443.6 440633 1.449 0.669 451.9 446416 1.241 0.529 459.9 451990 1.129 0.418 467.9 457564 1.638 0.875 475.9 463138 1.386 0.583 483.9 468712 2.605 2.135 491.9 474286 1.443 1.170 499.9 479860 1.141 0.784