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Identify proposed drilling targets to address these questions.

Drilling the “ S hackleton sites” on the Portuguese Margin as a Quaternary Marine Reference Section. Workshop Goals. Identify the important scientific questions that can be addressed by IODP drilling of the Portuguese Margin. Identify proposed drilling targets to address these questions.

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Identify proposed drilling targets to address these questions.

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  1. Drilling the “Shackleton sites” on the Portuguese Margin as a Quaternary Marine Reference Section Workshop Goals • Identify the important scientific questions that can be • addressed by IODP drilling of the Portuguese Margin. • Identify proposed drilling targets to address these questions. • Synthesize outcomes of workshop in the form of a drilling proposal to be submitted to IODP by 1 April 2010.

  2. MD95-2042 Greenland Why drill the “Shackleton sites” on the Portuguese Margin? Millennial-scale climate variability that can be confidently correlated to Greenland ice cores What was the nature of millennial-scale variability in older glacial periods of the Pleistocene?

  3. The 'flickering switch' of late Pleistocene climate change K. C. Taylor, G. W.  Lamorey, G. A. Doyle, R. B. Alley, P. M. Grootes, P. A. Mayewski, J. W. C. White and L. K. Barlow Nature 361: 432-436, 1993. Did D-O cycles occur during previous glacial periods? If so, how did their structure and pacing compare to the last glaciation? NGRIP Proj. Members (2004)

  4. How did the character of millennial-scale variability change as orbital and glacial boundary conditions changed during the Pleistocene? orbital millennial June insolation 65oN Greenland 18O H1 H5 H4 H6 H2 H3 Age (ka)

  5. Building marine sediment analogs to the polar ice cores Two ice cores in one….. MD95-2042 (Portuguese Margin) A2 (AIM 12) A1 (AIM 8) A3 A4 benthic planktic 12 3 4 6 7 8 9 10 11 5 Shackleton et al. (2000, 2004) Cacho et al. (1999)

  6. Stratigraphy is the backbone of paleoceanography Even in the absence of an accurate time scale….. it is possible to determine the relative phasing of millennial scale variability by identifying the lead/lag relationship of proxy variables that monitor different components of the ocean-climate system in the same core.

  7. A1 (AIM8) A2 (AIM12) MD95-2042 Planktic G. bulloides benthic Shackleton et al. (2000, 2004) Depth (m) d18O Depth (m)

  8. Timing of Millennial-Scale Climate Change in Antarctica and Greenland During the Last Glacial Period Thomas BLUNIER, Edward J. BROOK “Over this period, the onset of seven major millennial-scale warmings in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years.” Science 5 January 2001:Vol. 291. no. 5501, pp. 109 - 112

  9. One-to-one coupling of glacial climate variability in Greenland and Antarctica EPICA Community Members (2006), Nature 444: 195-198.

  10. Fresh water forcing Bipolar Seesaw Has the bipolar seesaw been a persistant feature of the climate system during glacial periods? Vellinga and Wood (2002)

  11. NEEM North Greenland Eemian Ice Drilling Study of past interglacials

  12. Ice-Marine-Terrestrial Linkages GISP/ GRIP EDML pollen Speleothems (e.g., Corchia)

  13. A Quaternary Marine Reference Section Richard Alley, 2003, editorial to Paleoceanography, “Raising Paleoceanography” Follow the lead of the ice core community …….. “ generate a few internationally coordinated, multiply replicated, multi-parameter, high-resolution type sections of oceanic (and terrestrial) change.”

  14. Sampling and analysis Opportunity for a truly coordinated multi-proxy approach Micropaleo Transfer functions Nutrient availability/ Productivity C, N, Si isotopes Temperature Uk37, TEX86, Mg/Ca Salinity Combined T and 18O Eecological indicators Terrestrial vegetation Pollen, biomarkers, charcoal Deep-water circulation Benthic 13C, End, sort silt, Cd/Ca, Pa/Th Carbonate system B/Ca, 11B

  15. Whatever you do, do it at high resolution…. N. Shackleton

  16. Multiple holes, multiple spliced composite sections

  17. Building community support…….

  18. IODP-USIO JOIDES Resolution Operations Schedule Expedition Name Canterbury Basin Sea Level 317 4 Nov–4 Jan'10 Wilkes Land Glacial History 318 9 Mar Tentative 2010-2011 Schedule Juan de Fuca Hydrogeology Jul-Sep 2010 South Pacific Gyre Microbiology Oct-Dec 2010 Louisville Seamount Trail Dec 2010-Feb 2011

  19. Pre-Proposal SSEP Full (Pre2) External Review Full-x Final Review forwarded to SPC Full-x + Ext.Rev. + PRL SSP STP EPSP ? ? ? ? ? Deactivate Proposal Proposal Review Process Proponents (Proposal submission to IODP-MI)

  20. quickest possible drilling • submission for April 2010 deadline: • proposal gets evaluated at SSEP during May 2010 • if perfect and no revisions requested, sent out for external review • proposal + ext. reviews evaluated during SSEP Nov. 2010 meeting • if perfect, forwarded to SPC (assuming site survey data etc. exist and are fine), ranking in March 2011 • if at least one revision for SSEP (very likely), ranking in March 2012 instead

  21. 763-APL PORT-1A 37.83732 oN, -10.15505 oW 3099 m water depth 3 days of drilling 3 holes to 150 mbsf (base of Pleistocene)

  22. Questions to keep in mind: Which of the important scientific themes that form the IODP Initial Science Plan will drilling the Portuguese Margin address? 2. Why is it necessary that scientific ocean drilling be used to explore the problem? 3. What are the key unanswered questions to be addressed by scientific drilling of the Portuguese Margin? 4. What new aspect(s) of the problem will the proposed drilling address? 5. What new results are expected from the proposed drilling? 6. What new insights into the problem can only be gained by the proposed drilling? 7. What is the societal relevance of drilling the Portuguese Margin? 8. What are the specific hypotheses and/or models to be tested through drilling? 9. What are the best strategies for reaching the overall goals?

  23. IODP Science Advisory Structure (SAS)

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