Japan Geoscience Union Meeting 2018

Presentation information

[EJ] Poster

S (Solid Earth Sciences) » S-GD Geodesy

[S-GD02] Geodesy General Contributions & Global Geodetic Observing System

Wed. May 23, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Koji Matsuo(Geospatial Information Authority of Japan), Yusuke Yokota(Japan Coast Guard, Hydrographic and oceanographic department), Takahiro Wakasugi(国土交通省国土地理院)

[SGD02-P07] Heat flow in the solid Earth and changes in length of day

*Chuichi Kakuta1 (1.none)

Keywords:heat flow in the outer core , growth of the inner core, variations of lod

Long time changes in length of day(LOD)in the outer ocre are formed in stable layers near the core mantle boundary(CMB) and the cooling inner core boundary (ICB). We assume that the outer core is compressible. We determine the magnitude of changes in the LOD. We exculde the effects of a thermal wind becauses there are many ambiguous factors in the inner core. As a result,variations of the angular momentum are -7.23. 10-5. If the growth of the inner core to the present time since the radius of the inner core to be 375 km, is 2.7 Ga(Kumazawa et al.,1994)and 1.0 Ga(Labrosse et al.,2001),the rate of variations of the angular momentum is 0.87.10-13 yr-1, and -2.35. 10-13 yr-1. These values are less than the rate of the long time variations from tidal variations known in the present time d omega/omega = - 3.8.10-10 yr-1(Rochester,1973).