# Borneo High Resolution Holocene Speleothem Oxygen Isotope Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # 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: http://www.ncdc.noaa.gov/paleo/study/19885 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/pacific/borneo2016ba03enso.txt # # Archive: Speleothems # # Parameter_Keywords: oxygen isotopes, age control #--------------------------------------- # Contribution_Date # Date: 2016-03-17 #--------------------------------------- # Title # Study_Name: Borneo High Resolution Holocene Speleothem Oxygen Isotope Data #--------------------------------------- # Investigators # Investigators: Chen, S.; Hoffmann, S.S.; Lund, D.C.; Cobb, K.M.; Emile-Geay, J.; Adkins, J.F. #--------------------------------------- # Description and Notes # Description: Subannual oxygen isotope record in six Holocene time windows from stalagmite BA03, Bukit Assam Cave, Borneo, Malaysia. # 2500 yr window: 349.270-400.030mm, 2386.36-2597.86 Cal. year BP # 3300 yr window: 474.630-492.600mm, 3234.12-3383.87 Cal. year BP # 5200 yr window: 743.770-754.450mm, 5161.41-5225.49 Cal. year BP # 5700 yr window: 827.186-838.316mm, 5628.52-5708.02 Cal. year BP # 6700 yr window: 940.150-959.800mm, 6583.78-6740.98 Cal. year BP # 8200 yr window: 1054.680-1073.698mm, 8136.82-8316.72 Cal. year BP # # Also included is the ENSO-band (2-7 year) 30-yr window d18O standard deviation calculated from BA03 subannual time series, # as plotted in Figure 7 of Chen et al. (2016) EPSL, 442, 61-71 # # Provided Keywords: Holocene, ENSO, speleothem, oxygen isotopes #--------------------------------------- # Publication # Authors: Sang Chen, Sharon S. Hoffmann, David C. Lund, Kim M. Cobb, Julien Emile-Geay, Jess F. Adkins # Published_Date_or_Year: 2016-05-15 # Published_Title: A high-resolution speleothem record of western equatorial Pacific rainfall: Implications for Holocene ENSO evolution # Journal_Name: Earth and Planetary Science Letters # Volume: 442 # Edition: # Issue: # Pages: 61-71 # Report Number: # DOI: 10.1016/j.epsl.2016.02.050 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0012821X16300759 # Full_Citation: # Abstract: The El Nino-Southern Oscillation (ENSO) is the primary driver of interannual climate variability in the tropics and subtropics. Despite substantial progress in understanding ocean-atmosphere feedbacks that drive ENSO today, relatively little is known about its behavior on centennial and longer timescales. Paleoclimate records from lakes, corals, molluscs and deep-sea sediments generally suggest that ENSO variability was weaker during the mid-Holocene (4-6 kyrBP) than the late Holocene (0-4 kyrBP). However, discrepancies amongst the records preclude a clear timeline of Holocene ENSO evolution and therefore the attribution of ENSO variability to specific climate forcing mechanisms. Here we present d18O results from a U-Th dated speleothem in Malaysian Borneo sampled at sub-annual resolution. The d18O of Borneo rainfall is a robust proxy of regional convective intensity and precipitation amount, both of which are directly influenced by ENSO activity. Our estimates of stalagmite d18O variance at ENSO periods (2-7 yr) show a significant reduction in interannual variability during the mid-Holocene (3240-3380 and 5160-5230 yrBP) relative to both the late Holocene (2390-2590 yrBP) and early Holocene (6590-6730 yrBP). The Borneo results are therefore inconsistent with lacustrine records of ENSO from the eastern equatorial Pacific that show little or no ENSO variance during the early Holocene. Instead, our results support coral, mollusc and foraminiferal records from the central and eastern equatorial Pacific that show a mid-Holocene minimum in ENSO variance. Reduced mid-Holocene interannual d18O variability in Borneo coincides with an overall minimum in mean d18O from 3.5 to 5.5 kyrBP. Persistent warm pool convection would tend to enhance the Walker circulation during the mid-Holocene, which likely contributed to reduced ENSO variance during this period. This finding implies that both convective intensity and interannual variability in Borneo are driven by coupled air-sea dynamics that are sensitive to precessional insolation forcing. Isolating the exact mechanisms that drive long-term ENSO evolution will require additional high-resolution paleoclimatic reconstructions and further investigation of Holocene tropical climate evolution using coupled climate models. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: AGS-1103385 #------------------ # Site_Information # Site_Name: Bukit Assam Cave # Location: Ocean>Indian Ocean>Malaysia # Country: Malaysia # Northernmost_Latitude: 4.2587 # Southernmost_Latitude: 4.2587 # Easternmost_Longitude: 114.9649 # Westernmost_Longitude: 114.9649 # Elevation: 250 m #------------------ # Data_Collection # Collection_Name: BA03ENSO # First_Year: 8298 # Last_Year: 2401 # Time_Unit: cal yr BP # Core_Length: 1.3 m # Notes: separate time windows #--------------------------------------- # Chronology_Information # Chronology: # # Depth (mm) Age (yr BP) 2sigma errors Note # 0 -53 Top age assumed zero due to active dripping at time of stalagmite collection. Note: 9/14/2017 Age value for depth 0 corrected from 0 to -53 Cal. yr BP (core collected in 2003 CE) # 25.00 263 22 # 44.50 247 42 # 95.00 731 63 # 114.00 824 97 center point of isochron # 161.50 1205 32 # 195.00 1386 23 # 247.75 1596 70 # 277.14 1813 97 # 296.63 1932 18 # 321.40 2169 20 # 361.15 2472 32 # 418.20 2747 59 # 456.70 3116 94 center point of isochron # 495.70 3402 22 # 518.46 3516 25 # 580.96 3870 42 # 644.95 4276 44 # 697.91 4910 40 # 763.45 5032 111 center point of isochron # 773.65 5392 30 # 802.85 5444 39 # 865.09 5913 36 # 882.48 6078 60 # 916.76 6353 35 # 940.95 6601 34 # 965.49 6785 48 # 988.80 6869 69 # 1016.72 7217 133 # 1036.45 7750 119 # 1054.68 8132 48 # 1078.45 8385 61 # 1094.83 8501 52 # 1121.92 9558 50 # 1170.06 9806 91 # 1216.36 11128 111 # 1246.34 11627 128 # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ## age_calBP age, , , calendar years before present, , , , ,N ## d18Ocarbstdev delta18O standard deviation, calcium carbonate, , , ,speleothem, ENSO-band (2-7 year) 30-yr window d18O standard deviation, calculated from BA03 subannual time series,N # #---------------- # Data # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Value: age_calBP d18Ocarbstdev 2401.4 0.0606 2406.4 0.0445 2411.4 0.0511 2416.4 0.0557 2421.4 0.0543 2426.4 0.0529 2431.4 0.0537 2436.4 0.0545 2441.4 0.0490 2446.4 0.0459 2451.4 0.0470 2456.4 0.0511 2461.4 0.0498 2466.4 0.0489 2471.4 0.0514 2476.4 0.0527 2481.4 0.0587 2486.4 0.0554 2491.4 0.0599 2496.4 0.0557 2501.4 0.0495 2506.4 0.0480 2511.4 0.0444 2516.4 0.0466 2521.4 0.0454 2526.4 0.0481 2531.4 0.0483 2536.4 0.0476 2541.4 0.0478 2546.4 0.0482 2551.4 0.0484 2556.4 0.0481 2561.4 0.0480 2566.4 0.0501 2571.4 0.0464 2576.4 0.0488 2581.4 0.0518 3249.1 0.0347 3254.1 0.0343 3259.1 0.0407 3264.1 0.0500 3269.1 0.0496 3274.1 0.0515 3279.1 0.0517 3284.1 0.0512 3289.1 0.0506 3294.1 0.0391 3299.1 0.0388 3304.1 0.0344 3309.1 0.0393 3314.1 0.0391 3319.1 0.0348 3324.1 0.0347 3329.1 0.0363 3334.1 0.0399 3339.1 0.0347 3344.1 0.0347 3349.1 0.0341 3354.1 0.0341 3359.1 0.0357 3364.1 0.0328 3369.1 0.0345 5176 0.0256 5181 0.0276 5186 0.0307 5191 0.0336 5196 0.0361 5201 0.0380 5206 0.0374 5211 0.0359 5643.5 0.0376 5648.5 0.0385 5653.5 0.0353 5658.5 0.0304 5663.5 0.0395 5668.5 0.0406 5673.5 0.0395 5678.5 0.0376 5683.5 0.0399 5688.5 0.0385 6598.8 0.0357 6603.6 0.0335 6608.4 0.0346 6613.2 0.0351 6618.0 0.0379 6622.8 0.0362 6627.6 0.0358 6632.4 0.0381 6637.2 0.0373 6642.0 0.0371 6646.8 0.0320 6651.6 0.0346 6656.4 0.0395 6661.2 0.0413 6666.0 0.0442 6670.8 0.0473 6675.6 0.0563 6680.4 0.0549 6685.2 0.0555 6690.0 0.0536 6694.8 0.0515 6699.6 0.0640 6704.4 0.0596 6709.2 0.0572 6714.0 0.0530 6718.8 0.0548 6723.6 0.0567 8151.8 0.0592 8156.7 0.0589 8161.6 0.0577 8166.5 0.0545 8171.4 0.0485 8176.3 0.0416 8181.2 0.0272 8186.1 0.0182 8191.0 0.0183 8195.9 0.0206 8200.8 0.0212 8205.7 0.0294 8210.6 0.0385 8215.5 0.0382 8220.4 0.0392 8225.3 0.0405 8230.2 0.0482 8235.1 0.0469 8240.0 0.0425 8244.9 0.0492 8249.8 0.0509 8254.7 0.0568 8259.6 0.0529 8264.5 0.0558 8269.4 0.0562 8274.3 0.0504 8279.2 0.0482 8284.1 0.0424 8289.0 0.0407 8293.9 0.0330 8298.8 0.0272