197 SCIENTIFIC PROSPECTUSPUBLISHER'S NOTESDISCLAIMERSCIENTIFIC REPORTABSTRACTINTRODUCTIONBACKGROUND AND RECENT RESULTSPaleomagnetic Bias in Sedimentary Inclinations New Paleolatitude Data for the Emperor Seamounts Hotspot Motion and True Polar Wander SCIENTIFIC OBJECTIVES1. Determining the Paleolatitude and Age of the Emperor Seamount 2. Investigate The Time-Averaged Late Cretaceous to Early Tertiary Geomagnetic Field 3. Investigate Late Cretaceous to Early Tertiary Geomagnetic Paleointensity 4. Source and Melting History of the Hawaiian HotspotDRILLING STRATEGY Secular Variation in Previous Ocean Drilling Studies Secular Variation in Previous Ocean Drilling Studies Group 1: Meiji Seamount (~86 Ma) Group 2: Detroit Seamount (81 Ma) Group 3: Nintoku (>56 Ma), Ojin (56 Ma), and Koko Seamounts (>48 Ma)UNDERWAY GEOPHYSICSSAMPLING STRATEGYShipboard and Shore-Based Samples LOGGING PLAN REFERENCES FIGURE CAPTIONS AND FIGURESFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9OPERATIONS PLAN AND TIME ESTIMATESOption 1Option 2Option 3SITE SUMMARIESSite: HE-1A (Site 192)Seismic Line: HE-1A/1BSite: HE-1BSite: HE-2Seismic Line: HE-2Site: HE-2ASeismic Line: HE-2ASite: HE-3Seismic Line: HE-3Site: HE-3ASeismic Line: HE-3A E-WSeismic Line: HE-3A N-SSite: HE-3BSeismic Line: HE-3B E-WSeismic Line: HE-3B N-SSite: HE-4ASeismic Line: HE-4A/4BSite: HE-4BSite: HE-5ASeismic Line: HE-5ASite: HE-5BSeismic Line: HE-5BSite: HE-5CSeismic Line: HE-5CSite: HE-5DSeismic Line: HE-5DSite: HE-6ASeismic Line: HE-6A/6BSite: HE-6BSCIENTIFIC PARTICIPANTSOCEAN DRILLING PROGRAMLEG 197 SCIENTIFIC PROSPECTUSMOTION OF THE HAWAIIAN HOTSPOT: A PALEOMAGNETIC TEST Dr. Robert A. DuncanCo-Chief ScientistOregon State UniversityCollege of Oceanic and Atmospheric Sciences104 Ocean Administration BuildingCorvallis OR 97331-5503USADr. John A. TardunoCo-Chief ScientistUniversity of RochesterDepartment of Earth andEnvironmental SciencesHutchison Hall 227Rochester NY 14627USA__________________Dr. Jack BaldaufDeputy Director of Science OperationsOcean Drilling ProgramTexas A&M University1000 Discovery DriveCollege Station TX 77845-9547USA_____________________Dr. Gary D. ActonLeg Project Manager and Staff ScientistOcean Drilling ProgramTexas A&M University1000 Discovery DriveCollege Station TX 77845-9547USAMay 2001PUBLISHER’S NOTESMaterial in this publication may be copied without restraint for library, abstract service, educational,or personal research purposes; however, this source should be appropriately acknowledged.Ocean Drilling Program Scientific Prospectus No. 97 (May 2001)Distribution: Electronic copies of this publication may be obtained from the ODP Publicationshomepage on the World Wide Web at: http://www-odp.tamu.edu/publicationsThis publication was prepared by the Ocean Drilling Program, Texas A&M University, as anaccount of work performed under the international Ocean Drilling Program, which is managed byJoint Oceanographic Institutions, Inc., under contract with the National Science Foundation.Funding for the program is provided by the following agencies:Australia/Canada/Chinese Taipei/Korea Consortium for Ocean Drilling Deutsche Forschungsgemeinschaft (Federal Republic of Germany)Institut National des Sciences de l'Univers-Centre National de la Recherche Scientifique(INSU CNRS; France)Ocean Research Institute of the University of Tokyo (Japan)National Science Foundation (United States)Natural Environment Research Council (United Kingdom)European Science Foundation Consortium for Ocean Drilling (Belgium, Denmark, Finland,Iceland, Ireland, Italy, The Netherlands, Norway, Portugal, Spain, Sweden, and Switzerland)Marine High-Technology Bureau of the State Science and Technology Commission of thePeople's Republic of ChinaDISCLAIMERAny opinions, findings, and conclusions or recommendations expressed in this publication arethose of the author(s) and do not necessarily reflect the views of the National Science Foundation,the participating agencies, Joint Oceanographic Institutions, Inc., Texas A&M University, or TexasA&M Research Foundation.This Scientific Prospectus is based on precruise JOIDES panel discussions and scientific inputfrom the designated Co-Chief Scientists on behalf of the drilling proponents. The operational planswithin reflect JOIDES Planning Committee and thematic panel priorities. During the course of thecruise, actual site operations may indicate to the Co-Chief Scientists and the Operations Managerthat it would be scientifically or operationally advantageous to amend the plan detailed in thisprospectus. It should be understood that any proposed changes to the plan presented here arecontingent upon approval of the Director of the Ocean Drilling Program in consultation with theScience and Operations Committees (successors to the Planning Committee) and the PollutionPrevention and Safety Panel.Technical Editors: Karen K. Graber and Lorri L. PetersLeg 197Scientific ProspectusPage 3ABSTRACT The bend in the Hawaiian-Emperor chain is the best example of a change in plate motion recordedin a fixed-hotspot frame of reference. Alternatively, the bend might primarily record differences inmotion of the Hawaiian hotspot relative to the Pacific lithosphere. Four lines of inquiry support thelatter view: (1) global plate motions predicted from relative plate motion data, (2) spreading ratedata from the North Pacific basin, (3) mantle flow modeling utilizing geoid and seismic tomographyconstraints, and (4) new paleomagnetic data from the Emperor chain. Although the rate of motion isdifficult to constrain because previous drilling has been limited, the best available paleomagneticdata suggest Pacific hotspots may have moved at rates comparable to those of lithospheric plates inLate Cretaceous to early Tertiary times (81-43 Ma). If correct, this requires a major change in howwe view mantle dynamics and the history of plate motions. This leg seeks to test the hypothesis ofsouthward motion of the Hawaiian hotspot by drilling five to six basement sites in the Emperorseamount trend. The principal drilling objective is to achieve moderate basement penetration (150-250 m) at these sites to obtain cores from lava flows suitable for paleomagnetic paleolatitude andradiometric age determinations. A comparison of these dated paleolatitude values with fixed andmoving hotspot predictions form the basis of the proposed test. Our sampling strategy will alsoallow us to address important geomagnetic