# 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/costa2017-39bb.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 39BB # Location: North Pacific Ocean # Country: # Northernmost_Latitude: 45.04507 # Southernmost_Latitude: 45.04507 # Easternmost_Longitude: -130.83318 # Westernmost_Longitude: -130.83318 # Elevation: -2794 #--------------------------------------- # Data_Collection # Collection_Name: AT26-19 39BB Costa17 # First_Year: 15628 # Last_Year: 408152 # 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 15629 0.409 0.006 4.5 18286 0.685 0.011 8.5 20944 0.818 0.013 12.5 23601 1.223 0.022 16.5 26259 1.294 0.023 20.5 28916 1.245 0.023 24.5 31574 1.263 0.024 28.5 34231 0.805 0.015 32.5 36889 0.934 0.017 36.5 39546 0.850 0.017 40.5 42204 0.762 0.015 44.5 44861 0.766 0.015 48.5 47519 0.789 0.015 52.5 50176 0.771 0.015 56.5 52834 0.741 0.015 60.5 55491 0.789 0.016 64.5 58149 0.726 0.015 68.5 60806 0.805 0.018 72.5 63464 0.834 0.019 76.5 66121 0.813 0.019 80.5 68779 0.818 0.019 84.5 71436 0.656 0.016 86.2 72566 0.670 0.018 90.2 75223 0.674 0.018 94.2 77881 0.706 0.020 98.2 80538 0.649 0.018 102.2 83196 0.523 0.014 106.2 85853 0.440 0.012 110.2 88511 0.370 0.010 114.2 91169 0.360 0.010 118.2 93826 0.394 0.011 122.2 96484 0.390 0.012 126.2 99141 0.353 0.011 130.2 101799 0.352 0.011 134.2 104456 0.317 0.010 138.2 107114 0.282 0.009 142.2 109771 0.320 0.010 146.2 112429 0.335 0.011 150.2 115086 0.451 0.015 154.2 117744 0.362 0.012 158.2 120401 0.326 0.011 162.2 123059 0.364 0.012 166.2 125716 0.499 0.018 170.2 128374 0.806 0.033 174.2 131031 1.210 0.056 178.2 133689 1.001 0.042 182.2 136378 1.342 0.063 186.2 139591 1.169 0.053 190.2 142804 1.175 0.054 194.2 146017 1.126 0.051 198.2 149230 1.118 0.053 202.2 152443 1.007 0.048 206.2 155656 1.065 0.056 210.2 158869 1.101 0.061 214.2 162082 1.082 0.063 218.2 165295 1.046 0.060 222.2 168508 0.996 0.060 226.2 171721 0.772 0.045 230.2 174934 0.805 0.051 234.2 178147 0.830 0.051 239 182003 0.852 0.055 243 185216 0.696 0.042 247 188429 0.459 0.032 251 191642 0.744 0.016 255 194855 0.420 0.028 259 198068 0.388 0.027 263 201281 0.371 0.025 267 204494 0.365 0.025 271 207707 0.365 0.025 275 210920 0.349 0.025 279 214133 0.338 0.024 283 217346 0.322 0.023 287 220559 0.294 0.021 291 223772 0.302 0.022 295 226985 0.265 0.019 299 230198 0.333 0.027 303 233412 0.402 0.036 307 236625 0.307 0.024 311 239838 0.411 0.036 315 243051 0.445 0.040 319 246264 0.514 0.047 323 249477 0.912 0.092 327 253132 0.940 0.092 331 256874 1.034 0.104 335 260615 1.184 0.122 339 264356 1.220 0.137 343 268098 1.382 0.172 347 271839 1.571 0.365 367 272212 0.746 0.137 351 272212 5.678 5.140 359 272212 2.492 1.108 371 273333 0.507 0.079 375 277820 0.447 0.064 379 282306 0.464 0.064 383 286793 0.489 0.065 387 291279 0.606 0.086 391.3 296102 0.601 0.087 395.3 300588 0.534 0.074 399.3 305075 0.497 0.077 403.3 309561 0.485 0.081 407.3 314048 0.422 0.070 411.3 318534 0.457 0.079 415.3 323021 0.359 0.063 419.3 327507 0.379 0.072 423.3 331994 0.460 0.092 427.3 336480 0.330 0.055 431.3 341309 0.913 0.224 435.3 347386 1.100 0.369 439.3 353462 1.130 0.370 443.3 359539 1.035 0.328 447.3 365615 0.964 0.293 451.3 371692 0.784 0.201 455.3 377769 0.814 0.220 459.3 383845 0.675 0.204 463.3 389922 0.594 0.155 467.3 395998 0.597 0.170 471.3 402075 0.470 0.122 475.3 408152 0.476 0.138