Formation and Elimination of Segmentation on the Reykjanes

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Formation and Elimination of Segmentation on the Reykjanes Ridge Fernando Martinez & Richard Hey

Formation and Elimination of Segmentation on the Reykjanes Ridge Fernando Martinez & Richard Hey Hawaii Institute of Geophysics and Planetology School of Ocean and Earth Science and Technology University of Hawaii at Manoa & R/V Marcus Langseth Shipboard Science Party: Ármann Höskuldsson, Deborah Eason, Jonathan Sleeper, Sigvaldi Thordarson, Irene Trujols, Joanna Dominiczak, Maria Laidla, Alica de Witt, Elías Eyþórsson, Jóhannesson, Chris Horvath, Ashley Paradiso With thanks to Ásdís Benediktsdóttir for magnetic data analysis and R. SEARLE & S. MERKOURIEV for generous data contributions

GREENLAND Bight FZ NORTH AMERICA RE YK JA NE S RI DG E ICELAND

GREENLAND Bight FZ NORTH AMERICA RE YK JA NE S RI DG E ICELAND EURASIA

3 MODES OF SEAFLOOR SPREADING FLANKING THE REYKJANES RIDGE MAGNETICS SATELLITE-DERIVED GRAVITY 1) UNSEGMENTED

3 MODES OF SEAFLOOR SPREADING FLANKING THE REYKJANES RIDGE MAGNETICS SATELLITE-DERIVED GRAVITY 1) UNSEGMENTED ORTHOGONAL SPREADING ON A LONG LINEAR RIDGE (THICK CRUST) 2) ORTHOGONAL SPREADING ON A SEGMENTED RIDGE (THINNER CRUST) 3) OBLIQUE SPREADING ON AN UNSEGMENTED LINEAR RIDGE (THICK CRUST)

R/V MARCUS G LANGSETH SURVEY TRACK GREENLAND ICELAND REYKJAVIK CRUISE MGL 1309 R/V MARCUS

R/V MARCUS G LANGSETH SURVEY TRACK GREENLAND ICELAND REYKJAVIK CRUISE MGL 1309 R/V MARCUS G LANGSETH MAIN DATA SETS: MULTIBEAM BATHYMETRY GRAVITY MAGNETICS

Tectonomagmatic regimes inferred to result from mantle plume temperature variations White, 1997, Phil. Trans.

Tectonomagmatic regimes inferred to result from mantle plume temperature variations White, 1997, Phil. Trans. R. Soc. Lond.

Red line: Spreading flow line

Red line: Spreading flow line

TOTAL VERTICAL MANTLE UPWELLING BETWEEN 6 -60 KM DEPTH UNSEGMENTED RIDGE VOLUME RATE OF

TOTAL VERTICAL MANTLE UPWELLING BETWEEN 6 -60 KM DEPTH UNSEGMENTED RIDGE VOLUME RATE OF UPWELLING = 12, 148 KM 3/M. Y. PEAK UPWELLING RATE = 6. 37 KM 3/M. Y. SEGMENTED RIDGE 52 X 30 KM VOLUME RATE OF UPWELLING = 8, 671 KM 3/M. Y. PEAK UPWELLING RATE = 5. 68 KM 3/M. Y. ~ 30 % less upwelling generated by segmented ridge than unsegmented ridge

Changes in Direction of Seafloor Spreading Revisited R. N. Hey, H. W. Menard, T.

Changes in Direction of Seafloor Spreading Revisited R. N. Hey, H. W. Menard, T. M. Atwater, D. W. Caress JGR, 1988

MAGNETIC ANOMALY

MAGNETIC ANOMALY

Magnetic isochrons show that ridge segments first migrate toward each other decreasing the offsets

Magnetic isochrons show that ridge segments first migrate toward each other decreasing the offsets across transform faults and non-transform discontinuities. Then the ridge segments break up into smaller segments to form an oblique plate boundary zone.

Thanks

Thanks

Reykjanes Reykjanes landfrileg lega og srkenni Einstakt nttrufarReykjanes Reykjanes landfrileg lega og srkenni Einstakt nttrufar
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