Study on viscoelastic structure and monitoring of global change by observation of uplifting and gravity in Alaska, US

2015 Fiscal Year Final Research Report

• Project/Area Number: 23253003
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Solid earth and planetary physics
• Research Institution: Tohoku University (2013-2015); The University of Tokyo (2011-2012)
• Principal Investigator: Miura Satoshi 東北大学, 理学(系)研究科(研究院), 教授 (70181849)
• Co-Investigator(Kenkyū-buntansha): SATO TADAHIRO 東北大学, 大学院理学研究科, 名誉教授 (10000176) ; FUJIMOTO HIROMI 東北大学, 大学院理学研究科, 名誉教授 (50107455) ; OHTA YUSAKU 東北大学, 大学院理学研究科, 准教授 (50451513) ; MOTOYUKI SATO 東北大学, 東北アジア研究センター, 教授 (40178778) ; TAKAHASHI HIROAKI 北海道大学, 大学院理学研究科, 准教授 (30301930) ; OKUBO SHUHEI 東京大学, 地震研究所, 教授 (30152078) ; KAZAMA TAKAHITO 京都大学, 大学院理学研究科, 助教 (20700363)
• Research Collaborator: Jeff Freymueller アラスカ大学, 地球物理学研究所, 教授 ; Chris Larsen アラスカ大学, 地球物理学研究所, 准教授 ; Max Kaufman アラスカ大学, 地球物理学研究所, 技術職員
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 地殻隆起 / 荷重変形 / GPS / 重力変化 / 粘弾性構造 / 後氷期隆起

Outline of Final Research Achievements

In order to study crustal uplifting and gravity change in southeastern Alaska, United States, we carried out continuous GPS and gravity measurements together with absolute gravity survey three times in the area. From the continuous GPS measurements, the maximum uplifting rate of 3 cm/year, which is consistent with the previous study, was derived. Since the continuous gravity measurements by a superconducting gravimeter demonstrated very small, almost no instrumental drift rate, we may be able to use the gravimeter complementing the absolute gravity survey. Gravity change rates obtained by the survey show -1 to -3 micro-gal/year, which is about a half of those for the period from 2006 to 2008. This discrepancy can be attributed to the effects of underground water and/or loading of precipitation.

Free Research Field

固体地球物理学