Japan Geoscience Union Meeting 2014

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Oral

Symbol S (Solid Earth Sciences) » S-CG Complex & General

[S-CG67_2AM2] Ocean Floor Geoscience

Fri. May 2, 2014 11:00 AM - 12:45 PM 418 (4F)

Convener:*Kyoko Okino(Ocean Research Institute, University of Tokyo), Keiichi Tadokoro(Research Center for Seismology, Volcanology and Earthquake and Volcano Research Center, Nagoya University), Osamu Ishizuka(Institute of Geoscience, Geological Survey of Japan/AIST), Tomohiro Toki(Faculty of Science, University of the Ryukyus), Narumi Takahashi(Earthquake and Tsunami Research Project for Disaster Prevention, Japan Agency for Marine-Earth Science and Technology), Chair:Tomohiro Toki(Faculty of Science, University of the Ryukyus), Kyoko Okino(Ocean Research Institute, University of Tokyo)

12:00 PM - 12:15 PM

[SCG67-P16_PG] Spreading stability at the mid-ocean ridges derived from 3D magnetic survey

3-min talk in an oral session

*Takeshi MATSUMOTO1, Yukitaka SATOH1, Yoshifumi NOGI2 (1.University of the Ryukyus, 2.National Institute of Polar Research)

Keywords:mid-ocean ridge, spreading rate, 3D magnetometry

The Shipboard Three Component Magnetometer (STCM) has provided vector data of the geomagnetic filed provided detailed information more than total magnetic force measurement. Previous study shows the results about relationship with ocean floor topography and standard deviation of magnetic boundary strike (MBS) calculated from Intensity of the Differential Vectors (ISDV) in Southeast Indian Ridge (SEIR) classified intermediate spreading rate. In this study, the standard deviation of MBS and half spreading rate were analyzed from STCM data in East Pacific Rise (EPR) of fast spreading ridge, Explorer Ridge (ER) and Southeast Indian Ridge (SEIR) classified intermediate spreading ridge and Mid Atlantic Ridge (MAR) categorized as slow spreading ridge. In EPR existing axial high, the results shows that standard deviation and half spreading rate are stable in west of EPR whereas standard deviation and half spreading rate are variability in east of EPR. However standard deviation is low and spreading rate is stable on both sides in MAR developed axial valley. Thus there is no relationship with topographic features and spreading of stability. Additionally, standard deviation of MBS is the low although half spreading rate has variability in ER. The results show differential MBS at the same position in SEIR. As a result, dispersion of MBS is caused by inaccurate measurements of magnetic anomaly. In addition, there is no clear relationship though the simulation was run about plate reconstruction. Therefore spreading stability is controlled by the balance among plate reconstruction, slab pull and magma provided from mantle.