Absolute Gravity Measurements in New Zealand for the techtonic studies in Southern Alphs and establishing absolute gravity net

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H05205
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: Fukuda Yoichi 京都大学, 理学研究科, 教授 (30133854)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 絶対重力測定 / 重力変化 / テクトニクス / ニュージーランド / 南アルプス / カイコウラ地震

Outline of Final Research Achievements

To enhance and extend the absolute gravity network, we have newly conducted absolute gravity measurements in New Zealand. As a result, we supported the result obtained by Bilham et al. (2016) about the gravity change in the Southern Alps. On the other hand, we showed that the trend of gravity decreases after the 2011 Christchurch earthquake was probably as same as that of before the earthquake. Furthermore, we revealed the gravity changes caused by the 2016 Kaikoura earthquake and showed that the regional differences in the relationship between the gravity changes and the height changes possibly depended on the tectonic characteristics of the regions.

Free Research Field

測地学，地球物理学

Academic Significance and Societal Importance of the Research Achievements

ニュージーランドでの絶対重力測定を実施することで，同国の重力に関連したさまざまな研究や社会的にも重要な度量衡・測量の基準となる絶対重力基準点網の強化に寄与した．さらに，南アルプスのテクトニクスに関連した重力変化や，クライストチャーチ地震やカイコウラ地震に伴う重力変化を検出することで，学術的に重要なその変動のメカニズムに関する知見を与えた．